Use common library in SuperStarTrek

2025-12-22 23:26:40 -08:00 · 2022-03-22 17:55:44 +11:00
parent 4fb62ce30c
commit 42c21bbc62
57 changed files with 1595 additions and 1682 deletions
--- a/00_Common/dotnet/Games.Common/IO/ConsoleIO.cs
+++ b/00_Common/dotnet/Games.Common/IO/ConsoleIO.cs
@@ -12,4 +12,6 @@ public sealed class ConsoleIO : TextIO
        : base(Console.In, Console.Out)
    {
    }
+
+    public override char ReadCharacter() => Console.ReadKey(intercept: true).KeyChar;
 }
--- a/00_Common/dotnet/Games.Common/IO/IReadWrite.cs
+++ b/00_Common/dotnet/Games.Common/IO/IReadWrite.cs
@@ -8,6 +8,12 @@ namespace Games.Common.IO;
 /// </summary>
 public interface IReadWrite
 {
+    /// <summary>
+    /// Reads a character from input.
+    /// </summary>
+    /// <returns>The character read.</returns>
+    char ReadCharacter();
+
    /// <summary>
    /// Reads a <see cref="float" /> value from input.
    /// </summary>
@@ -99,6 +105,13 @@ public interface IReadWrite
    /// </summary>
    /// <param name="format">The format <see cref="string" /> to be written.</param>
    /// <param name="value">The values to be inserted into the format.</param>
+    void Write(string format, params object[] values);
+
+    /// <summary>
+    /// Writes a formatted string to output followed by a new-line.
+    /// </summary>
+    /// <param name="format">The format <see cref="string" /> to be written.</param>
+    /// <param name="value">The values to be inserted into the format.</param>
    void WriteLine(string format, params object[] values);

    /// <summary>
--- a/00_Common/dotnet/Games.Common/IO/TextIO.cs
+++ b/00_Common/dotnet/Games.Common/IO/TextIO.cs
@@ -29,6 +29,15 @@ public class TextIO : IReadWrite
        _numberTokenReader = TokenReader.ForNumbers(this);
    }

+    public virtual char ReadCharacter()
+    {
+        while(true)
+        {
+            var ch = _input.Read();
+            if (ch != -1) { return (char)ch; }
+        }
+    }
+
    public float ReadNumber(string prompt) => ReadNumbers(prompt, 1)[0];

    public (float, float) Read2Numbers(string prompt)
@@ -99,6 +108,8 @@ public class TextIO : IReadWrite

    public void WriteLine(object value) => _output.WriteLine(value.ToString());

+    public void Write(string format, params object[] values) => _output.Write(format, values);
+
    public void WriteLine(string format, params object[] values) => _output.WriteLine(format, values);

    public void Write(Stream stream, bool keepOpen = false)
--- a/84_Super_Star_Trek/csharp/Commands/Command.cs
+++ b/84_Super_Star_Trek/csharp/Commands/Command.cs
@@ -1,34 +1,33 @@
 using System.ComponentModel;

-namespace SuperStarTrek.Commands
+namespace SuperStarTrek.Commands;
+
+internal enum Command
 {
-    internal enum Command
-    {
-        [Description("To set course")]
-        NAV,
+    [Description("To set course")]
+    NAV,

-        [Description("For short range sensor scan")]
-        SRS,
+    [Description("For short range sensor scan")]
+    SRS,

-        [Description("For long range sensor scan")]
-        LRS,
+    [Description("For long range sensor scan")]
+    LRS,

-        [Description("To fire phasers")]
-        PHA,
+    [Description("To fire phasers")]
+    PHA,

-        [Description("To fire photon torpedoes")]
-        TOR,
+    [Description("To fire photon torpedoes")]
+    TOR,

-        [Description("To raise or lower shields")]
-        SHE,
+    [Description("To raise or lower shields")]
+    SHE,

-        [Description("For damage control reports")]
-        DAM,
+    [Description("For damage control reports")]
+    DAM,

-        [Description("To call on library-computer")]
-        COM,
+    [Description("To call on library-computer")]
+    COM,

-        [Description("To resign your command")]
-        XXX
-    }
+    [Description("To resign your command")]
+    XXX
 }
--- a/84_Super_Star_Trek/csharp/Commands/CommandExtensions.cs
+++ b/84_Super_Star_Trek/csharp/Commands/CommandExtensions.cs
@@ -1,14 +1,13 @@
 using System.Reflection;
 using System.ComponentModel;

-namespace SuperStarTrek.Commands
+namespace SuperStarTrek.Commands;
+
+internal static class CommandExtensions
 {
-    internal static class CommandExtensions
-    {
-        internal static string GetDescription(this Command command) =>
-            typeof(Command)
-                .GetField(command.ToString())
-                .GetCustomAttribute<DescriptionAttribute>()
-                .Description;
-    }
+    internal static string GetDescription(this Command command) =>
+        typeof(Command)
+            .GetField(command.ToString())
+            .GetCustomAttribute<DescriptionAttribute>()
+            .Description;
 }
--- a/84_Super_Star_Trek/csharp/Commands/CommandResult.cs
+++ b/84_Super_Star_Trek/csharp/Commands/CommandResult.cs
@@ -1,23 +1,22 @@
-namespace SuperStarTrek.Commands
+namespace SuperStarTrek.Commands;
+
+internal class CommandResult
 {
-    internal class CommandResult
+    public static readonly CommandResult Ok = new(false);
+    public static readonly CommandResult GameOver = new(true);
+
+    private CommandResult(bool isGameOver)
    {
-        public static readonly CommandResult Ok = new(false);
-        public static readonly CommandResult GameOver = new(true);
-
-        private CommandResult(bool isGameOver)
-        {
-            IsGameOver = isGameOver;
-        }
-
-        private CommandResult(float timeElapsed)
-        {
-            TimeElapsed = timeElapsed;
-        }
-
-        public bool IsGameOver { get; }
-        public float TimeElapsed { get; }
-
-        public static CommandResult Elapsed(float timeElapsed) => new(timeElapsed);
+        IsGameOver = isGameOver;
    }
+
+    private CommandResult(float timeElapsed)
+    {
+        TimeElapsed = timeElapsed;
+    }
+
+    public bool IsGameOver { get; }
+    public float TimeElapsed { get; }
+
+    public static CommandResult Elapsed(float timeElapsed) => new(timeElapsed);
 }
--- a/84_Super_Star_Trek/csharp/Game.cs
+++ b/84_Super_Star_Trek/csharp/Game.cs
@@ -1,131 +1,128 @@
 using System;
+using Games.Common.IO;
+using Games.Common.Randomness;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;
 using SuperStarTrek.Systems;
 using SuperStarTrek.Systems.ComputerFunctions;

-namespace SuperStarTrek
+namespace SuperStarTrek;
+
+internal class Game
 {
-    internal class Game
+    private readonly TextIO _io;
+    private readonly IRandom _random;
+
+    private int _initialStardate;
+    private int _finalStarDate;
+    private float _currentStardate;
+    private Coordinates _currentQuadrant;
+    private Galaxy _galaxy;
+    private int _initialKlingonCount;
+    private Enterprise _enterprise;
+
+    internal Game(TextIO io, IRandom random)
    {
-        private readonly Output _output;
-        private readonly Input _input;
-        private readonly Random _random;
-
-        private int _initialStardate;
-        private int _finalStarDate;
-        private float _currentStardate;
-        private Coordinates _currentQuadrant;
-        private Galaxy _galaxy;
-        private int _initialKlingonCount;
-        private Enterprise _enterprise;
-
-        internal Game(Output output, Input input, Random random)
-        {
-            _output = output;
-            _input = input;
-            _random = random;
-        }
-
-        internal float Stardate => _currentStardate;
-
-        internal float StardatesRemaining => _finalStarDate - _currentStardate;
-
-        internal void DoIntroduction()
-        {
-            _output.Write(Strings.Title);
-
-            if (_input.GetYesNo("Do you need instructions", Input.YesNoMode.FalseOnN))
-            {
-                _output.Write(Strings.Instructions);
-
-                _input.WaitForAnyKeyButEnter("to continue");
-            }
-        }
-
-        internal void Play()
-        {
-            Initialise();
-            var gameOver = false;
-
-            while (!gameOver)
-            {
-                var command = _input.GetCommand();
-
-                var result = _enterprise.Execute(command);
-
-                gameOver = result.IsGameOver || CheckIfStranded();
-                _currentStardate += result.TimeElapsed;
-                gameOver |= _currentStardate > _finalStarDate;
-            }
-
-            if (_galaxy.KlingonCount > 0)
-            {
-                _output.Write(Strings.EndOfMission, _currentStardate, _galaxy.KlingonCount);
-            }
-            else
-            {
-                _output.Write(Strings.Congratulations, GetEfficiency());
-            }
-        }
-
-        private void Initialise()
-        {
-            _currentStardate = _initialStardate = _random.GetInt(20, 40) * 100;
-            _finalStarDate = _initialStardate + _random.GetInt(25, 35);
-
-            _currentQuadrant = _random.GetCoordinate();
-
-            _galaxy = new Galaxy(_random);
-            _initialKlingonCount = _galaxy.KlingonCount;
-
-            _enterprise = new Enterprise(3000, _random.GetCoordinate(), _output, _random, _input);
-            _enterprise
-                .Add(new WarpEngines(_enterprise, _output, _input))
-                .Add(new ShortRangeSensors(_enterprise, _galaxy, this, _output))
-                .Add(new LongRangeSensors(_galaxy, _output))
-                .Add(new PhaserControl(_enterprise, _output, _input, _random))
-                .Add(new PhotonTubes(10, _enterprise, _output, _input))
-                .Add(new ShieldControl(_enterprise, _output, _input))
-                .Add(new DamageControl(_enterprise, _output))
-                .Add(new LibraryComputer(
-                    _output,
-                    _input,
-                    new CumulativeGalacticRecord(_output, _galaxy),
-                    new StatusReport(this, _galaxy, _enterprise, _output),
-                    new TorpedoDataCalculator(_enterprise, _output),
-                    new StarbaseDataCalculator(_enterprise, _output),
-                    new DirectionDistanceCalculator(_enterprise, _output, _input),
-                    new GalaxyRegionMap(_output, _galaxy)));
-
-            _output.Write(Strings.Enterprise);
-            _output.Write(
-                Strings.Orders,
-                _galaxy.KlingonCount,
-                _finalStarDate,
-                _finalStarDate - _initialStardate,
-                _galaxy.StarbaseCount > 1 ? "are" : "is",
-                _galaxy.StarbaseCount,
-                _galaxy.StarbaseCount > 1 ? "s" : "");
-
-            _input.WaitForAnyKeyButEnter("when ready to accept command");
-
-            _enterprise.StartIn(BuildCurrentQuadrant());
-        }
-
-        private Quadrant BuildCurrentQuadrant() =>
-           new Quadrant(_galaxy[_currentQuadrant], _enterprise, _random, _galaxy, _input, _output);
-
-        internal bool Replay() => _galaxy.StarbaseCount > 0 && _input.GetString(Strings.ReplayPrompt, "Aye");
-
-        private bool CheckIfStranded()
-        {
-            if (_enterprise.IsStranded) { _output.Write(Strings.Stranded); }
-            return _enterprise.IsStranded;
-        }
-
-        private float GetEfficiency() =>
-            1000 * (float)Math.Pow(_initialKlingonCount / (_currentStardate - _initialStardate), 2);
+        _io = io;
+        _random = random;
    }
+
+    internal float Stardate => _currentStardate;
+
+    internal float StardatesRemaining => _finalStarDate - _currentStardate;
+
+    internal void DoIntroduction()
+    {
+        _io.Write(Strings.Title);
+
+        if (_io.GetYesNo("Do you need instructions", IReadWriteExtensions.YesNoMode.FalseOnN))
+        {
+            _io.Write(Strings.Instructions);
+
+            _io.WaitForAnyKeyButEnter("to continue");
+        }
+    }
+
+    internal void Play()
+    {
+        Initialise();
+        var gameOver = false;
+
+        while (!gameOver)
+        {
+            var command = _io.ReadCommand();
+
+            var result = _enterprise.Execute(command);
+
+            gameOver = result.IsGameOver || CheckIfStranded();
+            _currentStardate += result.TimeElapsed;
+            gameOver |= _currentStardate > _finalStarDate;
+        }
+
+        if (_galaxy.KlingonCount > 0)
+        {
+            _io.Write(Strings.EndOfMission, _currentStardate, _galaxy.KlingonCount);
+        }
+        else
+        {
+            _io.Write(Strings.Congratulations, CalculateEfficiency());
+        }
+    }
+
+    private void Initialise()
+    {
+        _currentStardate = _initialStardate = _random.Next(20, 40) * 100;
+        _finalStarDate = _initialStardate + _random.Next(25, 35);
+
+        _currentQuadrant = _random.NextCoordinate();
+
+        _galaxy = new Galaxy(_random);
+        _initialKlingonCount = _galaxy.KlingonCount;
+
+        _enterprise = new Enterprise(3000, _random.NextCoordinate(), _io, _random);
+        _enterprise
+            .Add(new WarpEngines(_enterprise, _io))
+            .Add(new ShortRangeSensors(_enterprise, _galaxy, this, _io))
+            .Add(new LongRangeSensors(_galaxy, _io))
+            .Add(new PhaserControl(_enterprise, _io, _random))
+            .Add(new PhotonTubes(10, _enterprise, _io))
+            .Add(new ShieldControl(_enterprise, _io))
+            .Add(new DamageControl(_enterprise, _io))
+            .Add(new LibraryComputer(
+                _io,
+                new CumulativeGalacticRecord(_io, _galaxy),
+                new StatusReport(this, _galaxy, _enterprise, _io),
+                new TorpedoDataCalculator(_enterprise, _io),
+                new StarbaseDataCalculator(_enterprise, _io),
+                new DirectionDistanceCalculator(_enterprise, _io),
+                new GalaxyRegionMap(_io, _galaxy)));
+
+        _io.Write(Strings.Enterprise);
+        _io.Write(
+            Strings.Orders,
+            _galaxy.KlingonCount,
+            _finalStarDate,
+            _finalStarDate - _initialStardate,
+            _galaxy.StarbaseCount > 1 ? "are" : "is",
+            _galaxy.StarbaseCount,
+            _galaxy.StarbaseCount > 1 ? "s" : "");
+
+        _io.WaitForAnyKeyButEnter("when ready to accept command");
+
+        _enterprise.StartIn(BuildCurrentQuadrant());
+    }
+
+    private Quadrant BuildCurrentQuadrant() => new(_galaxy[_currentQuadrant], _enterprise, _random, _galaxy, _io);
+
+    internal bool Replay() => _galaxy.StarbaseCount > 0 && _io.ReadExpectedString(Strings.ReplayPrompt, "Aye");
+
+    private bool CheckIfStranded()
+    {
+        if (_enterprise.IsStranded) { _io.Write(Strings.Stranded); }
+        return _enterprise.IsStranded;
+    }
+
+    private float CalculateEfficiency() =>
+        1000 * (float)Math.Pow(_initialKlingonCount / (_currentStardate - _initialStardate), 2);
 }
--- a/84_Super_Star_Trek/csharp/IRandomExtensions.cs
+++ b/84_Super_Star_Trek/csharp/IRandomExtensions.cs
@@ -0,0 +1,16 @@
+using Games.Common.Randomness;
+using SuperStarTrek.Space;
+
+namespace SuperStarTrek;
+
+internal static class IRandomExtensions
+{
+    internal static Coordinates NextCoordinate(this IRandom random) =>
+        new Coordinates(random.Next1To8Inclusive() - 1, random.Next1To8Inclusive() - 1);
+
+    // Duplicates the algorithm used in the original code to get an integer value from 1 to 8, inclusive:
+    //     475 DEF FNR(R)=INT(RND(R)*7.98+1.01)
+    // Returns a value from 1 to 8, inclusive.
+    // Note there's a slight bias away from the extreme values, 1 and 8.
+    internal static int Next1To8Inclusive(this IRandom random) => (int)(random.NextFloat() * 7.98 + 1.01);
+}
--- a/84_Super_Star_Trek/csharp/IReadWriteExtensions.cs
+++ b/84_Super_Star_Trek/csharp/IReadWriteExtensions.cs
@@ -0,0 +1,89 @@
+using System;
+using System.Linq;
+using Games.Common.IO;
+using SuperStarTrek.Commands;
+using SuperStarTrek.Space;
+using static System.StringComparison;
+
+namespace SuperStarTrek;
+
+internal static class IReadWriteExtensions
+{
+    internal static void WaitForAnyKeyButEnter(this IReadWrite io, string prompt)
+    {
+        io.Write($"Hit any key but Enter {prompt} ");
+        while (io.ReadCharacter() == '\r');
+    }
+
+    internal static (float X, float Y) GetCoordinates(this IReadWrite io, string prompt) =>
+        io.Read2Numbers($"{prompt} (X,Y)");
+
+    internal static bool TryReadNumberInRange(
+        this IReadWrite io,
+        string prompt,
+        float minValue,
+        float maxValue,
+        out float value)
+    {
+        value = io.ReadNumber($"{prompt} ({minValue}-{maxValue})");
+
+        return value >= minValue && value <= maxValue;
+    }
+
+    internal static bool ReadExpectedString(this IReadWrite io, string prompt, string trueValue) =>
+        io.ReadString(prompt).Equals(trueValue, InvariantCultureIgnoreCase);
+
+    internal static Command ReadCommand(this IReadWrite io)
+    {
+        while(true)
+        {
+            var response = io.ReadString("Command");
+
+            if (response.Length >= 3 &&
+                Enum.TryParse(response.Substring(0, 3), ignoreCase: true, out Command parsedCommand))
+            {
+                return parsedCommand;
+            }
+
+            io.WriteLine("Enter one of the following:");
+            foreach (var command in Enum.GetValues(typeof(Command)).OfType<Command>())
+            {
+                io.WriteLine($"  {command}  ({command.GetDescription()})");
+            }
+            io.WriteLine();
+        }
+    }
+
+    internal static bool TryReadCourse(this IReadWrite io, string prompt, string officer, out Course course)
+    {
+        if (!io.TryReadNumberInRange(prompt, 1, 9, out var direction))
+        {
+            io.WriteLine($"{officer} reports, 'Incorrect course data, sir!'");
+            course = default;
+            return false;
+        }
+
+        course = new Course(direction);
+        return true;
+    }
+
+    internal static bool GetYesNo(this IReadWrite io, string prompt, YesNoMode mode)
+    {
+        var response = io.ReadString($"{prompt} (Y/N)").ToUpperInvariant();
+
+        return (mode, response) switch
+        {
+            (YesNoMode.FalseOnN, "N") => false,
+            (YesNoMode.FalseOnN, _) => true,
+            (YesNoMode.TrueOnY, "Y") => true,
+            (YesNoMode.TrueOnY, _) => false,
+            _ => throw new ArgumentOutOfRangeException(nameof(mode), mode, "Invalid value")
+        };
+    }
+
+    internal enum YesNoMode
+    {
+        TrueOnY,
+        FalseOnN
+    }
+}
--- a/84_Super_Star_Trek/csharp/Input.cs
+++ b/84_Super_Star_Trek/csharp/Input.cs
@@ -1,159 +0,0 @@
-using System;
-using System.Linq;
-using SuperStarTrek.Commands;
-using SuperStarTrek.Space;
-using static System.StringComparison;
-
-namespace SuperStarTrek
-{
-    internal class Input
-    {
-        private readonly Output _output;
-
-        internal Input(Output output)
-        {
-            _output = output;
-        }
-
-        internal void WaitForAnyKeyButEnter(string prompt)
-        {
-            _output.Write($"Hit any key but Enter {prompt} ");
-            while (Console.ReadKey(intercept: true).Key == ConsoleKey.Enter);
-        }
-
-        internal string GetString(string prompt)
-        {
-            _output.Prompt(prompt);
-            return Console.ReadLine();
-        }
-
-        internal float GetNumber(string prompt)
-        {
-            _output.Prompt(prompt);
-
-            while (true)
-            {
-                var response = Console.ReadLine();
-                if (float.TryParse(response, out var value))
-                {
-                    return value;
-                }
-
-                _output.WriteLine("!Number expected - retry input line");
-                _output.Prompt();
-            }
-        }
-
-        internal (float X, float Y) GetCoordinates(string prompt)
-        {
-            _output.Prompt($"{prompt} (X,Y)");
-            var responses = ReadNumbers(2);
-            return (responses[0], responses[1]);
-        }
-
-        internal bool TryGetNumber(string prompt, float minValue, float maxValue, out float value)
-        {
-            value = GetNumber($"{prompt} ({minValue}-{maxValue})");
-
-            return value >= minValue && value <= maxValue;
-        }
-
-        internal bool GetString(string replayPrompt, string trueValue) =>
-            GetString(replayPrompt).Equals(trueValue, InvariantCultureIgnoreCase);
-
-        internal Command GetCommand()
-        {
-            while(true)
-            {
-                var response = GetString("Command");
-
-                if (response.Length >= 3 &&
-                    Enum.TryParse(response.Substring(0, 3), ignoreCase: true, out Command parsedCommand))
-                {
-                    return parsedCommand;
-                }
-
-                _output.WriteLine("Enter one of the following:");
-                foreach (var command in Enum.GetValues(typeof(Command)).OfType<Command>())
-                {
-                    _output.WriteLine($"  {command}  ({command.GetDescription()})");
-                }
-                _output.WriteLine();
-            }
-        }
-
-        internal bool TryGetCourse(string prompt, string officer, out Course course)
-        {
-            if (!TryGetNumber(prompt, 1, 9, out var direction))
-            {
-                _output.WriteLine($"{officer} reports, 'Incorrect course data, sir!'");
-                course = default;
-                return false;
-            }
-
-            course = new Course(direction);
-            return true;
-        }
-
-        internal bool GetYesNo(string prompt, YesNoMode mode)
-        {
-            _output.Prompt($"{prompt} (Y/N)");
-            var response = Console.ReadLine().ToUpperInvariant();
-
-            return (mode, response) switch
-            {
-                (YesNoMode.FalseOnN, "N") => false,
-                (YesNoMode.FalseOnN, _) => true,
-                (YesNoMode.TrueOnY, "Y") => true,
-                (YesNoMode.TrueOnY, _) => false,
-                _ => throw new ArgumentOutOfRangeException(nameof(mode), mode, "Invalid value")
-            };
-        }
-
-        private float[] ReadNumbers(int quantity)
-        {
-            var numbers = new float[quantity];
-            var index = 0;
-            bool tryAgain;
-
-            do
-            {
-                tryAgain = false;
-                var responses = Console.ReadLine().Split(',');
-                if (responses.Length > quantity)
-                {
-                    _output.WriteLine("!Extra input ingored");
-                }
-
-                for (; index < responses.Length; index++)
-                {
-                    if (!float.TryParse(responses[index], out numbers[index]))
-                    {
-                        _output.WriteLine("!Number expected - retry input line");
-                        _output.Prompt();
-                        tryAgain = true;
-                        break;
-                    }
-                }
-            } while (tryAgain);
-
-            if (index < quantity)
-            {
-                _output.Prompt("?");
-                var responses = ReadNumbers(quantity - index);
-                for (int i = 0; i < responses.Length; i++, index++)
-                {
-                    numbers[index] = responses[i];
-                }
-            }
-
-            return numbers;
-        }
-
-        internal enum YesNoMode
-        {
-            TrueOnY,
-            FalseOnN
-        }
-    }
-}
--- a/84_Super_Star_Trek/csharp/Objects/Enterprise.cs
+++ b/84_Super_Star_Trek/csharp/Objects/Enterprise.cs
@@ -1,231 +1,230 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
+using Games.Common.Randomness;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;
 using SuperStarTrek.Systems;

-namespace SuperStarTrek.Objects
+namespace SuperStarTrek.Objects;
+
+internal class Enterprise
 {
-    internal class Enterprise
+    private readonly int _maxEnergy;
+    private readonly IReadWrite _io;
+    private readonly List<Subsystem> _systems;
+    private readonly Dictionary<Command, Subsystem> _commandExecutors;
+    private readonly IRandom _random;
+    private Quadrant _quadrant;
+
+    public Enterprise(int maxEnergy, Coordinates sector, IReadWrite io, IRandom random)
    {
-        private readonly int _maxEnergy;
-        private readonly Output _output;
-        private readonly List<Subsystem> _systems;
-        private readonly Dictionary<Command, Subsystem> _commandExecutors;
-        private readonly Random _random;
-        private readonly Input _input;
-        private Quadrant _quadrant;
+        SectorCoordinates = sector;
+        TotalEnergy = _maxEnergy = maxEnergy;

-        public Enterprise(int maxEnergy, Coordinates sector, Output output, Random random, Input input)
-        {
-            SectorCoordinates = sector;
-            TotalEnergy = _maxEnergy = maxEnergy;
-
-            _systems = new List<Subsystem>();
-            _commandExecutors = new Dictionary<Command, Subsystem>();
-            _output = output;
-            _random = random;
-            _input = input;
-        }
-
-        internal Quadrant Quadrant => _quadrant;
-
-        internal Coordinates QuadrantCoordinates => _quadrant.Coordinates;
-
-        internal Coordinates SectorCoordinates { get; private set; }
-
-        internal string Condition => GetCondition();
-
-        internal LibraryComputer Computer => (LibraryComputer)_commandExecutors[Command.COM];
-
-        internal ShieldControl ShieldControl => (ShieldControl)_commandExecutors[Command.SHE];
-
-        internal float Energy => TotalEnergy - ShieldControl.ShieldEnergy;
-
-        internal float TotalEnergy { get; private set; }
-
-        internal int DamagedSystemCount => _systems.Count(s => s.IsDamaged);
-
-        internal IEnumerable<Subsystem> Systems => _systems;
-
-        internal PhotonTubes PhotonTubes => (PhotonTubes)_commandExecutors[Command.TOR];
-
-        internal bool IsDocked => _quadrant.EnterpriseIsNextToStarbase;
-
-        internal bool IsStranded => TotalEnergy < 10 || Energy < 10 && ShieldControl.IsDamaged;
-
-        internal Enterprise Add(Subsystem system)
-        {
-            _systems.Add(system);
-            _commandExecutors[system.Command] = system;
-
-            return this;
-        }
-
-        internal void StartIn(Quadrant quadrant)
-        {
-            _quadrant = quadrant;
-            quadrant.Display(Strings.StartText);
-        }
-
-        private string GetCondition() =>
-            IsDocked switch
-            {
-                true => "Docked",
-                false when _quadrant.HasKlingons => "*Red*",
-                false when Energy / _maxEnergy < 0.1f => "Yellow",
-                false => "Green"
-            };
-
-        internal CommandResult Execute(Command command)
-        {
-            if (command == Command.XXX) { return CommandResult.GameOver; }
-
-            return _commandExecutors[command].ExecuteCommand(_quadrant);
-        }
-
-        internal void Refuel() => TotalEnergy = _maxEnergy;
-
-        public override string ToString() => "<*>";
-
-        internal void UseEnergy(float amountUsed)
-        {
-            TotalEnergy -= amountUsed;
-        }
-
-        internal CommandResult TakeHit(Coordinates sector, int hitStrength)
-        {
-            _output.WriteLine($"{hitStrength} unit hit on Enterprise from sector {sector}");
-            ShieldControl.AbsorbHit(hitStrength);
-
-            if (ShieldControl.ShieldEnergy <= 0)
-            {
-                _output.WriteLine(Strings.Destroyed);
-                return CommandResult.GameOver;
-            }
-
-            _output.WriteLine($"      <Shields down to {ShieldControl.ShieldEnergy} units>");
-
-            if (hitStrength >= 20)
-            {
-                TakeDamage(hitStrength);
-            }
-
-            return CommandResult.Ok;
-        }
-
-        private void TakeDamage(float hitStrength)
-        {
-            var hitShieldRatio = hitStrength / ShieldControl.ShieldEnergy;
-            if (_random.GetFloat() > 0.6 || hitShieldRatio <= 0.02f)
-            {
-                return;
-            }
-
-            var system = _systems[_random.Get1To8Inclusive() - 1];
-            system.TakeDamage(hitShieldRatio + 0.5f * _random.GetFloat());
-            _output.WriteLine($"Damage Control reports, '{system.Name} damaged by the hit.'");
-        }
-
-        internal void RepairSystems(float repairWorkDone)
-        {
-            var repairedSystems = new List<string>();
-
-            foreach (var system in _systems.Where(s => s.IsDamaged))
-            {
-                if (system.Repair(repairWorkDone))
-                {
-                    repairedSystems.Add(system.Name);
-                }
-            }
-
-            if (repairedSystems.Any())
-            {
-                _output.WriteLine("Damage Control report:");
-                foreach (var systemName in repairedSystems)
-                {
-                    _output.WriteLine($"        {systemName} repair completed.");
-                }
-            }
-        }
-
-        internal void VaryConditionOfRandomSystem()
-        {
-            if (_random.GetFloat() > 0.2f) { return; }
-
-            var system = _systems[_random.Get1To8Inclusive() - 1];
-            _output.Write($"Damage Control report:  {system.Name} ");
-            if (_random.GetFloat() >= 0.6)
-            {
-                system.Repair(_random.GetFloat() * 3 + 1);
-                _output.WriteLine("state of repair improved");
-            }
-            else
-            {
-                system.TakeDamage(_random.GetFloat() * 5 + 1);
-                _output.WriteLine("damaged");
-            }
-        }
-
-        internal float Move(Course course, float warpFactor, int distance)
-        {
-            var (quadrant, sector) = MoveWithinQuadrant(course, distance) ?? MoveBeyondQuadrant(course, distance);
-
-            if (quadrant != _quadrant.Coordinates)
-            {
-                _quadrant = new Quadrant(_quadrant.Galaxy[quadrant], this, _random, _quadrant.Galaxy, _input, _output);
-            }
-            _quadrant.SetEnterpriseSector(sector);
-            SectorCoordinates = sector;
-
-            TotalEnergy -= distance + 10;
-            if (Energy < 0)
-            {
-                _output.WriteLine("Shield Control supplies energy to complete the maneuver.");
-                ShieldControl.ShieldEnergy = Math.Max(0, TotalEnergy);
-            }
-
-            return GetTimeElapsed(quadrant, warpFactor);
-        }
-
-        private (Coordinates, Coordinates)? MoveWithinQuadrant(Course course, int distance)
-        {
-            var currentSector = SectorCoordinates;
-            foreach (var (sector, index) in course.GetSectorsFrom(SectorCoordinates).Select((s, i) => (s, i)))
-            {
-                if (distance == 0) { break; }
-
-                if (_quadrant.HasObjectAt(sector))
-                {
-                    _output.WriteLine($"Warp engines shut down at sector {currentSector} dues to bad navigation");
-                    distance = 0;
-                    break;
-                }
-
-                currentSector = sector;
-                distance -= 1;
-            }
-
-            return distance == 0 ? (_quadrant.Coordinates, currentSector) : null;
-        }
-
-        private (Coordinates, Coordinates) MoveBeyondQuadrant(Course course, int distance)
-        {
-            var (complete, quadrant, sector) = course.GetDestination(QuadrantCoordinates, SectorCoordinates, distance);
-
-            if (!complete)
-            {
-                _output.Write(Strings.PermissionDenied, sector, quadrant);
-            }
-
-            return (quadrant, sector);
-        }
-
-        private float GetTimeElapsed(Coordinates finalQuadrant, float warpFactor) =>
-            finalQuadrant == _quadrant.Coordinates
-                ? Math.Min(1, (float)Math.Round(warpFactor, 1, MidpointRounding.ToZero))
-                : 1;
+        _systems = new List<Subsystem>();
+        _commandExecutors = new Dictionary<Command, Subsystem>();
+        _io = io;
+        _random = random;
    }
+
+    internal Quadrant Quadrant => _quadrant;
+
+    internal Coordinates QuadrantCoordinates => _quadrant.Coordinates;
+
+    internal Coordinates SectorCoordinates { get; private set; }
+
+    internal string Condition => GetCondition();
+
+    internal LibraryComputer Computer => (LibraryComputer)_commandExecutors[Command.COM];
+
+    internal ShieldControl ShieldControl => (ShieldControl)_commandExecutors[Command.SHE];
+
+    internal float Energy => TotalEnergy - ShieldControl.ShieldEnergy;
+
+    internal float TotalEnergy { get; private set; }
+
+    internal int DamagedSystemCount => _systems.Count(s => s.IsDamaged);
+
+    internal IEnumerable<Subsystem> Systems => _systems;
+
+    internal PhotonTubes PhotonTubes => (PhotonTubes)_commandExecutors[Command.TOR];
+
+    internal bool IsDocked => _quadrant.EnterpriseIsNextToStarbase;
+
+    internal bool IsStranded => TotalEnergy < 10 || Energy < 10 && ShieldControl.IsDamaged;
+
+    internal Enterprise Add(Subsystem system)
+    {
+        _systems.Add(system);
+        _commandExecutors[system.Command] = system;
+
+        return this;
+    }
+
+    internal void StartIn(Quadrant quadrant)
+    {
+        _quadrant = quadrant;
+        quadrant.Display(Strings.StartText);
+    }
+
+    private string GetCondition() =>
+        IsDocked switch
+        {
+            true => "Docked",
+            false when _quadrant.HasKlingons => "*Red*",
+            false when Energy / _maxEnergy < 0.1f => "Yellow",
+            false => "Green"
+        };
+
+    internal CommandResult Execute(Command command)
+    {
+        if (command == Command.XXX) { return CommandResult.GameOver; }
+
+        return _commandExecutors[command].ExecuteCommand(_quadrant);
+    }
+
+    internal void Refuel() => TotalEnergy = _maxEnergy;
+
+    public override string ToString() => "<*>";
+
+    internal void UseEnergy(float amountUsed)
+    {
+        TotalEnergy -= amountUsed;
+    }
+
+    internal CommandResult TakeHit(Coordinates sector, int hitStrength)
+    {
+        _io.WriteLine($"{hitStrength} unit hit on Enterprise from sector {sector}");
+        ShieldControl.AbsorbHit(hitStrength);
+
+        if (ShieldControl.ShieldEnergy <= 0)
+        {
+            _io.WriteLine(Strings.Destroyed);
+            return CommandResult.GameOver;
+        }
+
+        _io.WriteLine($"      <Shields down to {ShieldControl.ShieldEnergy} units>");
+
+        if (hitStrength >= 20)
+        {
+            TakeDamage(hitStrength);
+        }
+
+        return CommandResult.Ok;
+    }
+
+    private void TakeDamage(float hitStrength)
+    {
+        var hitShieldRatio = hitStrength / ShieldControl.ShieldEnergy;
+        if (_random.NextFloat() > 0.6 || hitShieldRatio <= 0.02f)
+        {
+            return;
+        }
+
+        var system = _systems[_random.Next1To8Inclusive() - 1];
+        system.TakeDamage(hitShieldRatio + 0.5f * _random.NextFloat());
+        _io.WriteLine($"Damage Control reports, '{system.Name} damaged by the hit.'");
+    }
+
+    internal void RepairSystems(float repairWorkDone)
+    {
+        var repairedSystems = new List<string>();
+
+        foreach (var system in _systems.Where(s => s.IsDamaged))
+        {
+            if (system.Repair(repairWorkDone))
+            {
+                repairedSystems.Add(system.Name);
+            }
+        }
+
+        if (repairedSystems.Any())
+        {
+            _io.WriteLine("Damage Control report:");
+            foreach (var systemName in repairedSystems)
+            {
+                _io.WriteLine($"        {systemName} repair completed.");
+            }
+        }
+    }
+
+    internal void VaryConditionOfRandomSystem()
+    {
+        if (_random.NextFloat() > 0.2f) { return; }
+
+        var system = _systems[_random.Next1To8Inclusive() - 1];
+        _io.Write($"Damage Control report:  {system.Name} ");
+        if (_random.NextFloat() >= 0.6)
+        {
+            system.Repair(_random.NextFloat() * 3 + 1);
+            _io.WriteLine("state of repair improved");
+        }
+        else
+        {
+            system.TakeDamage(_random.NextFloat() * 5 + 1);
+            _io.WriteLine("damaged");
+        }
+    }
+
+    internal float Move(Course course, float warpFactor, int distance)
+    {
+        var (quadrant, sector) = MoveWithinQuadrant(course, distance) ?? MoveBeyondQuadrant(course, distance);
+
+        if (quadrant != _quadrant.Coordinates)
+        {
+            _quadrant = new Quadrant(_quadrant.Galaxy[quadrant], this, _random, _quadrant.Galaxy, _io);
+        }
+        _quadrant.SetEnterpriseSector(sector);
+        SectorCoordinates = sector;
+
+        TotalEnergy -= distance + 10;
+        if (Energy < 0)
+        {
+            _io.WriteLine("Shield Control supplies energy to complete the maneuver.");
+            ShieldControl.ShieldEnergy = Math.Max(0, TotalEnergy);
+        }
+
+        return GetTimeElapsed(quadrant, warpFactor);
+    }
+
+    private (Coordinates, Coordinates)? MoveWithinQuadrant(Course course, int distance)
+    {
+        var currentSector = SectorCoordinates;
+        foreach (var (sector, index) in course.GetSectorsFrom(SectorCoordinates).Select((s, i) => (s, i)))
+        {
+            if (distance == 0) { break; }
+
+            if (_quadrant.HasObjectAt(sector))
+            {
+                _io.WriteLine($"Warp engines shut down at sector {currentSector} dues to bad navigation");
+                distance = 0;
+                break;
+            }
+
+            currentSector = sector;
+            distance -= 1;
+        }
+
+        return distance == 0 ? (_quadrant.Coordinates, currentSector) : null;
+    }
+
+    private (Coordinates, Coordinates) MoveBeyondQuadrant(Course course, int distance)
+    {
+        var (complete, quadrant, sector) = course.GetDestination(QuadrantCoordinates, SectorCoordinates, distance);
+
+        if (!complete)
+        {
+            _io.Write(Strings.PermissionDenied, sector, quadrant);
+        }
+
+        return (quadrant, sector);
+    }
+
+    private float GetTimeElapsed(Coordinates finalQuadrant, float warpFactor) =>
+        finalQuadrant == _quadrant.Coordinates
+            ? Math.Min(1, (float)Math.Round(warpFactor, 1, MidpointRounding.ToZero))
+            : 1;
 }
--- a/84_Super_Star_Trek/csharp/Objects/Klingon.cs
+++ b/84_Super_Star_Trek/csharp/Objects/Klingon.cs
@@ -1,43 +1,43 @@
+using Games.Common.Randomness;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Objects
+namespace SuperStarTrek.Objects;
+
+internal class Klingon
 {
-    internal class Klingon
+    private readonly IRandom _random;
+
+    internal Klingon(Coordinates sector, IRandom random)
    {
-        private readonly Random _random;
-
-        internal Klingon(Coordinates sector, Random random)
-        {
-            Sector = sector;
-            _random = random;
-            Energy = _random.GetFloat(100, 300);
-        }
-
-        internal float Energy { get; private set; }
-
-        internal Coordinates Sector { get; private set; }
-
-        public override string ToString() => "+K+";
-
-        internal CommandResult FireOn(Enterprise enterprise)
-        {
-            var attackStrength = _random.GetFloat();
-            var distanceToEnterprise = Sector.GetDistanceTo(enterprise.SectorCoordinates);
-            var hitStrength = (int)(Energy * (2 + attackStrength) / distanceToEnterprise);
-            Energy /= 3 + attackStrength;
-
-            return enterprise.TakeHit(Sector, hitStrength);
-        }
-
-        internal bool TakeHit(int hitStrength)
-        {
-            if (hitStrength < 0.15 * Energy) { return false; }
-
-            Energy -= hitStrength;
-            return true;
-        }
-
-        internal void MoveTo(Coordinates newSector) => Sector = newSector;
+        Sector = sector;
+        _random = random;
+        Energy = _random.NextFloat(100, 300);
    }
+
+    internal float Energy { get; private set; }
+
+    internal Coordinates Sector { get; private set; }
+
+    public override string ToString() => "+K+";
+
+    internal CommandResult FireOn(Enterprise enterprise)
+    {
+        var attackStrength = _random.NextFloat();
+        var distanceToEnterprise = Sector.GetDistanceTo(enterprise.SectorCoordinates);
+        var hitStrength = (int)(Energy * (2 + attackStrength) / distanceToEnterprise);
+        Energy /= 3 + attackStrength;
+
+        return enterprise.TakeHit(Sector, hitStrength);
+    }
+
+    internal bool TakeHit(int hitStrength)
+    {
+        if (hitStrength < 0.15 * Energy) { return false; }
+
+        Energy -= hitStrength;
+        return true;
+    }
+
+    internal void MoveTo(Coordinates newSector) => Sector = newSector;
 }
--- a/84_Super_Star_Trek/csharp/Objects/Star.cs
+++ b/84_Super_Star_Trek/csharp/Objects/Star.cs
@@ -1,7 +1,6 @@
-namespace SuperStarTrek.Objects
+namespace SuperStarTrek.Objects;
+
+internal class Star
 {
-    internal class Star
-    {
-        public override string ToString() => " * ";
-    }
+    public override string ToString() => " * ";
 }
--- a/84_Super_Star_Trek/csharp/Objects/Starbase.cs
+++ b/84_Super_Star_Trek/csharp/Objects/Starbase.cs
@@ -1,45 +1,44 @@
+using Games.Common.IO;
+using Games.Common.Randomness;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Objects
+namespace SuperStarTrek.Objects;
+
+internal class Starbase
 {
-    internal class Starbase
+    private readonly IReadWrite _io;
+    private readonly float _repairDelay;
+
+    internal Starbase(Coordinates sector, IRandom random, IReadWrite io)
    {
-        private readonly Input _input;
-        private readonly Output _output;
-        private readonly float _repairDelay;
-
-        internal Starbase(Coordinates sector, Random random, Input input, Output output)
-        {
-            Sector = sector;
-            _repairDelay = random.GetFloat() * 0.5f;
-            _input = input;
-            _output = output;
-        }
-
-        internal Coordinates Sector { get; }
-
-        public override string ToString() => ">!<";
-
-        internal bool TryRepair(Enterprise enterprise, out float repairTime)
-        {
-            repairTime = enterprise.DamagedSystemCount * 0.1f + _repairDelay;
-            if (repairTime >= 1) { repairTime = 0.9f; }
-
-            _output.Write(Strings.RepairEstimate, repairTime);
-            if (_input.GetYesNo(Strings.RepairPrompt, Input.YesNoMode.TrueOnY))
-            {
-                foreach (var system in enterprise.Systems)
-                {
-                    system.Repair();
-                }
-                return true;
-            }
-
-            repairTime = 0;
-            return false;
-        }
-
-        internal void ProtectEnterprise() => _output.WriteLine(Strings.Protected);
+        Sector = sector;
+        _repairDelay = random.NextFloat(0.5f);
+        _io = io;
    }
+
+    internal Coordinates Sector { get; }
+
+    public override string ToString() => ">!<";
+
+    internal bool TryRepair(Enterprise enterprise, out float repairTime)
+    {
+        repairTime = enterprise.DamagedSystemCount * 0.1f + _repairDelay;
+        if (repairTime >= 1) { repairTime = 0.9f; }
+
+        _io.Write(Strings.RepairEstimate, repairTime);
+        if (_io.GetYesNo(Strings.RepairPrompt, IReadWriteExtensions.YesNoMode.TrueOnY))
+        {
+            foreach (var system in enterprise.Systems)
+            {
+                system.Repair();
+            }
+            return true;
+        }
+
+        repairTime = 0;
+        return false;
+    }
+
+    internal void ProtectEnterprise() => _io.WriteLine(Strings.Protected);
 }
--- a/84_Super_Star_Trek/csharp/Output.cs
+++ b/84_Super_Star_Trek/csharp/Output.cs
@@ -1,40 +0,0 @@
-using System;
-
-namespace SuperStarTrek
-{
-    internal class Output
-    {
-        internal Output Write(string text)
-        {
-            Console.Write(text);
-            return this;
-        }
-
-        internal Output Write(string format, params object[] args)
-        {
-            Console.Write(format, args);
-            return this;
-        }
-
-        internal Output WriteLine(string text = "")
-        {
-            Console.WriteLine(text);
-            return this;
-        }
-
-
-        internal Output NextLine()
-        {
-            Console.WriteLine();
-            return this;
-        }
-
-
-        internal Output Prompt(string text = "")
-        {
-            Console.Write($"{text}? ");
-            return this;
-        }
-
-    }
-}
--- a/84_Super_Star_Trek/csharp/Program.cs
+++ b/84_Super_Star_Trek/csharp/Program.cs
@@ -23,24 +23,18 @@
 // ****  CONVERTED TO MICROSOFT C# 2/20/21 BY ANDREW COOPER
 // ****

-namespace SuperStarTrek
+using Games.Common.IO;
+using Games.Common.Randomness;
+using SuperStarTrek;
+
+var io = new ConsoleIO();
+var random = new RandomNumberGenerator();
+
+var game = new Game(io, random);
+
+game.DoIntroduction();
+
+do
 {
-    internal class Program
-    {
-        static void Main()
-        {
-            var output = new Output();
-            var input = new Input(output);
-            var random = new Random();
-
-            var game = new Game(output, input, random);
-
-            game.DoIntroduction();
-
-            do
-            {
-                game.Play();
-            } while (game.Replay());
-        }
-    }
-}
+    game.Play();
+} while (game.Replay());
--- a/84_Super_Star_Trek/csharp/Random.cs
+++ b/84_Super_Star_Trek/csharp/Random.cs
@@ -1,25 +0,0 @@
-using SuperStarTrek.Space;
-
-namespace SuperStarTrek
-{
-    internal class Random
-    {
-        private readonly System.Random _random = new();
-
-        internal Coordinates GetCoordinate() => new Coordinates(Get1To8Inclusive() - 1, Get1To8Inclusive() - 1);
-
-        // Duplicates the algorithm used in the original code to get an integer value from 1 to 8, inclusive:
-        //     475 DEF FNR(R)=INT(RND(R)*7.98+1.01)
-        // Returns a value from 1 to 8, inclusive.
-        // Note there's a slight bias away from the extreme values, 1 and 8.
-        internal int Get1To8Inclusive() => (int)(GetFloat() * 7.98 + 1.01);
-
-        internal int GetInt(int inclusiveMinValue, int exclusiveMaxValue) =>
-            _random.Next(inclusiveMinValue, exclusiveMaxValue);
-
-        internal float GetFloat() => (float)_random.NextDouble();
-
-        internal float GetFloat(float inclusiveMinValue, float exclusiveMaxValue)
-            => GetFloat() * (exclusiveMaxValue - inclusiveMinValue) + inclusiveMinValue;
-    }
-}
--- a/84_Super_Star_Trek/csharp/Resources/Enterprise.txt
+++ b/84_Super_Star_Trek/csharp/Resources/Enterprise.txt
@@ -16,3 +16,9 @@
                          '----------------'

                    THE USS ENTERPRISE --- NCC-1701
+
+
+
+
+
+
--- a/84_Super_Star_Trek/csharp/Resources/Instructions.txt
+++ b/84_Super_Star_Trek/csharp/Resources/Instructions.txt
@@ -104,3 +104,4 @@ COM command = Library-Computer
     Option 5 = Galactic Region Name Map
        This option prints the names of the sixteen major
        galactic regions referred to in the game.
+
--- a/84_Super_Star_Trek/csharp/Resources/NowEntering.txt
+++ b/84_Super_Star_Trek/csharp/Resources/NowEntering.txt
@@ -1,2 +1,3 @@

 Now entering {0} quadrant . . .
+
--- a/84_Super_Star_Trek/csharp/Resources/Orders.txt
+++ b/84_Super_Star_Trek/csharp/Resources/Orders.txt
@@ -3,3 +3,4 @@ Your orders are as follows:
  the galaxy before they can attack federation headquarters
  on stardate {1}. This gives you {2} days. There {3}
  {4} starbase{5} in the galaxy for resupplying your ship.
+
--- a/84_Super_Star_Trek/csharp/Resources/StartText.txt
+++ b/84_Super_Star_Trek/csharp/Resources/StartText.txt
@@ -2,3 +2,4 @@

 Your mission begins with your starship located
 in the galactic quadrant, '{0}'.
+
--- a/84_Super_Star_Trek/csharp/Resources/Title.txt
+++ b/84_Super_Star_Trek/csharp/Resources/Title.txt
@@ -17,3 +17,11 @@
          *                                   *
          *                                   *
          *************************************
+
+
+
+
+
+
+
+
--- a/84_Super_Star_Trek/csharp/Space/Coordinates.cs
+++ b/84_Super_Star_Trek/csharp/Space/Coordinates.cs
@@ -1,70 +1,69 @@
 using System;
 using SuperStarTrek.Utils;

-namespace SuperStarTrek.Space
+namespace SuperStarTrek.Space;
+
+// Represents the corrdintate of a quadrant in the galaxy, or a sector in a quadrant.
+// Note that the origin is top-left, x increase downwards, and y increases to the right.
+internal record Coordinates
 {
-    // Represents the corrdintate of a quadrant in the galaxy, or a sector in a quadrant.
-    // Note that the origin is top-left, x increase downwards, and y increases to the right.
-    internal record Coordinates
+    internal Coordinates(int x, int y)
    {
-        internal Coordinates(int x, int y)
-        {
-            X = Validated(x, nameof(x));
-            Y = Validated(y, nameof(y));
+        X = Validated(x, nameof(x));
+        Y = Validated(y, nameof(y));

-            RegionIndex = (X << 1) + (Y >> 2);
-            SubRegionIndex = Y % 4;
+        RegionIndex = (X << 1) + (Y >> 2);
+        SubRegionIndex = Y % 4;
+    }
+
+    internal int X { get; }
+
+    internal int Y { get; }
+
+    internal int RegionIndex { get; }
+
+    internal int SubRegionIndex { get; }
+
+    private static int Validated(int value, string argumentName)
+    {
+        if (value >= 0 && value <= 7) { return value; }
+
+        throw new ArgumentOutOfRangeException(argumentName, value, "Must be 0 to 7 inclusive");
+    }
+
+    private static bool IsValid(int value) => value >= 0 && value <= 7;
+
+    public override string ToString() => $"{X+1} , {Y+1}";
+
+    internal void Deconstruct(out int x, out int y)
+    {
+        x = X;
+        y = Y;
+    }
+
+    internal static bool TryCreate(float x, float y, out Coordinates coordinates)
+    {
+        var roundedX = Round(x);
+        var roundedY = Round(y);
+
+        if (IsValid(roundedX) && IsValid(roundedY))
+        {
+            coordinates = new Coordinates(roundedX, roundedY);
+            return true;
        }

-        internal int X { get; }
+        coordinates = default;
+        return false;

-        internal int Y { get; }
+        static int Round(float value) => (int)Math.Round(value, MidpointRounding.AwayFromZero);
+    }

-        internal int RegionIndex { get; }
+    internal (float Direction, float Distance) GetDirectionAndDistanceTo(Coordinates destination) =>
+        DirectionAndDistance.From(this).To(destination);

-        internal int SubRegionIndex { get; }
-
-        private static int Validated(int value, string argumentName)
-        {
-            if (value >= 0 && value <= 7) { return value; }
-
-            throw new ArgumentOutOfRangeException(argumentName, value, "Must be 0 to 7 inclusive");
-        }
-
-        private static bool IsValid(int value) => value >= 0 && value <= 7;
-
-        public override string ToString() => $"{X+1} , {Y+1}";
-
-        internal void Deconstruct(out int x, out int y)
-        {
-            x = X;
-            y = Y;
-        }
-
-        internal static bool TryCreate(float x, float y, out Coordinates coordinates)
-        {
-            var roundedX = Round(x);
-            var roundedY = Round(y);
-
-            if (IsValid(roundedX) && IsValid(roundedY))
-            {
-                coordinates = new Coordinates(roundedX, roundedY);
-                return true;
-            }
-
-            coordinates = default;
-            return false;
-
-            static int Round(float value) => (int)Math.Round(value, MidpointRounding.AwayFromZero);
-        }
-
-        internal (float Direction, float Distance) GetDirectionAndDistanceTo(Coordinates destination) =>
-            DirectionAndDistance.From(this).To(destination);
-
-        internal float GetDistanceTo(Coordinates destination)
-        {
-            var (_, distance) = GetDirectionAndDistanceTo(destination);
-            return distance;
-        }
+    internal float GetDistanceTo(Coordinates destination)
+    {
+        var (_, distance) = GetDirectionAndDistanceTo(destination);
+        return distance;
    }
 }
--- a/84_Super_Star_Trek/csharp/Space/Course.cs
+++ b/84_Super_Star_Trek/csharp/Space/Course.cs
@@ -1,98 +1,97 @@
 using System;
 using System.Collections.Generic;

-namespace SuperStarTrek.Space
+namespace SuperStarTrek.Space;
+
+// Implements the course calculations from the original code:
+//     530 FORI=1TO9:C(I,1)=0:C(I,2)=0:NEXTI
+//     540 C(3,1)=-1:C(2,1)=-1:C(4,1)=-1:C(4,2)=-1:C(5,2)=-1:C(6,2)=-1
+//     600 C(1,2)=1:C(2,2)=1:C(6,1)=1:C(7,1)=1:C(8,1)=1:C(8,2)=1:C(9,2)=1
+//
+//     3110 X1=C(C1,1)+(C(C1+1,1)-C(C1,1))*(C1-INT(C1))
+//     3140 X2=C(C1,2)+(C(C1+1,2)-C(C1,2))*(C1-INT(C1))
+internal class Course
 {
-    // Implements the course calculations from the original code:
-    //     530 FORI=1TO9:C(I,1)=0:C(I,2)=0:NEXTI
-    //     540 C(3,1)=-1:C(2,1)=-1:C(4,1)=-1:C(4,2)=-1:C(5,2)=-1:C(6,2)=-1
-    //     600 C(1,2)=1:C(2,2)=1:C(6,1)=1:C(7,1)=1:C(8,1)=1:C(8,2)=1:C(9,2)=1
-    //
-    //     3110 X1=C(C1,1)+(C(C1+1,1)-C(C1,1))*(C1-INT(C1))
-    //     3140 X2=C(C1,2)+(C(C1+1,2)-C(C1,2))*(C1-INT(C1))
-    internal class Course
+    private static readonly (int DeltaX, int DeltaY)[] cardinals = new[]
    {
-        private static readonly (int DeltaX, int DeltaY)[] cardinals = new[]
+        (0, 1),
+        (-1, 1),
+        (-1, 0),
+        (-1, -1),
+        (0, -1),
+        (1, -1),
+        (1, 0),
+        (1, 1),
+        (0, 1)
+    };
+
+    internal Course(float direction)
+    {
+        if (direction < 1 || direction > 9)
        {
-            (0, 1),
-            (-1, 1),
-            (-1, 0),
-            (-1, -1),
-            (0, -1),
-            (1, -1),
-            (1, 0),
-            (1, 1),
-            (0, 1)
-        };
-
-        internal Course(float direction)
-        {
-            if (direction < 1 || direction > 9)
-            {
-                throw new ArgumentOutOfRangeException(
-                    nameof(direction),
-                    direction,
-                    "Must be between 1 and 9, inclusive.");
-            }
-
-            var cardinalDirection = (int)(direction - 1) % 8;
-            var fractionalDirection = direction - (int)direction;
-
-            var baseCardinal = cardinals[cardinalDirection];
-            var nextCardinal = cardinals[cardinalDirection + 1];
-
-            DeltaX = baseCardinal.DeltaX + (nextCardinal.DeltaX - baseCardinal.DeltaX) * fractionalDirection;
-            DeltaY = baseCardinal.DeltaY + (nextCardinal.DeltaY - baseCardinal.DeltaY) * fractionalDirection;
+            throw new ArgumentOutOfRangeException(
+                nameof(direction),
+                direction,
+                "Must be between 1 and 9, inclusive.");
        }

-        internal float DeltaX { get; }
+        var cardinalDirection = (int)(direction - 1) % 8;
+        var fractionalDirection = direction - (int)direction;

-        internal float DeltaY { get; }
+        var baseCardinal = cardinals[cardinalDirection];
+        var nextCardinal = cardinals[cardinalDirection + 1];

-        internal IEnumerable<Coordinates> GetSectorsFrom(Coordinates start)
+        DeltaX = baseCardinal.DeltaX + (nextCardinal.DeltaX - baseCardinal.DeltaX) * fractionalDirection;
+        DeltaY = baseCardinal.DeltaY + (nextCardinal.DeltaY - baseCardinal.DeltaY) * fractionalDirection;
+    }
+
+    internal float DeltaX { get; }
+
+    internal float DeltaY { get; }
+
+    internal IEnumerable<Coordinates> GetSectorsFrom(Coordinates start)
+    {
+        (float x, float y) = start;
+
+        while(true)
        {
-            (float x, float y) = start;
+            x += DeltaX;
+            y += DeltaY;

-            while(true)
+            if (!Coordinates.TryCreate(x, y, out var coordinates))
            {
-                x += DeltaX;
-                y += DeltaY;
-
-                if (!Coordinates.TryCreate(x, y, out var coordinates))
-                {
-                    yield break;
-                }
-
-                yield return coordinates;
-            }
-        }
-
-        internal (bool, Coordinates, Coordinates) GetDestination(Coordinates quadrant, Coordinates sector, int distance)
-        {
-            var (xComplete, quadrantX, sectorX) = GetNewCoordinate(quadrant.X, sector.X, DeltaX * distance);
-            var (yComplete, quadrantY, sectorY) = GetNewCoordinate(quadrant.Y, sector.Y, DeltaY * distance);
-
-            return (xComplete && yComplete, new Coordinates(quadrantX, quadrantY), new Coordinates(sectorX, sectorY));
-        }
-
-        private static (bool, int, int) GetNewCoordinate(int quadrant, int sector, float sectorsTravelled)
-        {
-            var galacticCoordinate = quadrant * 8 + sector + sectorsTravelled;
-            var newQuadrant = (int)(galacticCoordinate / 8);
-            var newSector = (int)(galacticCoordinate - newQuadrant * 8);
-
-            if (newSector < 0)
-            {
-                newQuadrant -= 1;
-                newSector += 8;
+                yield break;
            }

-            return newQuadrant switch
-            {
-                < 0 => (false, 0, 0),
-                > 7 => (false, 7, 7),
-                _ => (true, newQuadrant, newSector)
-            };
+            yield return coordinates;
        }
    }
+
+    internal (bool, Coordinates, Coordinates) GetDestination(Coordinates quadrant, Coordinates sector, int distance)
+    {
+        var (xComplete, quadrantX, sectorX) = GetNewCoordinate(quadrant.X, sector.X, DeltaX * distance);
+        var (yComplete, quadrantY, sectorY) = GetNewCoordinate(quadrant.Y, sector.Y, DeltaY * distance);
+
+        return (xComplete && yComplete, new Coordinates(quadrantX, quadrantY), new Coordinates(sectorX, sectorY));
+    }
+
+    private static (bool, int, int) GetNewCoordinate(int quadrant, int sector, float sectorsTravelled)
+    {
+        var galacticCoordinate = quadrant * 8 + sector + sectorsTravelled;
+        var newQuadrant = (int)(galacticCoordinate / 8);
+        var newSector = (int)(galacticCoordinate - newQuadrant * 8);
+
+        if (newSector < 0)
+        {
+            newQuadrant -= 1;
+            newSector += 8;
+        }
+
+        return newQuadrant switch
+        {
+            < 0 => (false, 0, 0),
+            > 7 => (false, 7, 7),
+            _ => (true, newQuadrant, newSector)
+        };
+    }
 }
--- a/84_Super_Star_Trek/csharp/Space/Galaxy.cs
+++ b/84_Super_Star_Trek/csharp/Space/Galaxy.cs
@@ -1,64 +1,64 @@
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.Randomness;
 using SuperStarTrek.Resources;

 using static System.StringSplitOptions;

-namespace SuperStarTrek.Space
+namespace SuperStarTrek.Space;
+
+internal class Galaxy
 {
-    internal class Galaxy
+    private static readonly string[] _regionNames;
+    private static readonly string[] _subRegionIdentifiers;
+    private readonly QuadrantInfo[][] _quadrants;
+
+    static Galaxy()
    {
-        private static readonly string[] _regionNames;
-        private static readonly string[] _subRegionIdentifiers;
-        private readonly QuadrantInfo[][] _quadrants;
+        _regionNames = Strings.RegionNames.Split(new[] { ' ', '\n' }, RemoveEmptyEntries | TrimEntries);
+        _subRegionIdentifiers = new[] { "I", "II", "III", "IV" };
+    }

-        static Galaxy()
-        {
-            _regionNames = Strings.RegionNames.Split(new[] { ' ', '\n' }, RemoveEmptyEntries | TrimEntries);
-            _subRegionIdentifiers = new[] { "I", "II", "III", "IV" };
-        }
-
-        internal Galaxy(Random random)
-        {
-            _quadrants = Enumerable
+    internal Galaxy(IRandom random)
+    {
+        _quadrants = Enumerable
+            .Range(0, 8)
+            .Select(x => Enumerable
                .Range(0, 8)
-                .Select(x => Enumerable
-                    .Range(0, 8)
-                    .Select(y => new Coordinates(x, y))
-                    .Select(c => QuadrantInfo.Create(c, GetQuadrantName(c), random))
-                    .ToArray())
-                .ToArray();
+                .Select(y => new Coordinates(x, y))
+                .Select(c => QuadrantInfo.Create(c, GetQuadrantName(c), random))
+                .ToArray())
+            .ToArray();

-            if (StarbaseCount == 0)
+        if (StarbaseCount == 0)
+        {
+            var randomQuadrant = this[random.NextCoordinate()];
+            randomQuadrant.AddStarbase();
+
+            if (randomQuadrant.KlingonCount < 2)
            {
-                var randomQuadrant = this[random.GetCoordinate()];
-                randomQuadrant.AddStarbase();
-
-                if (randomQuadrant.KlingonCount < 2)
-                {
-                    randomQuadrant.AddKlingon();
-                }
+                randomQuadrant.AddKlingon();
            }
        }
-
-        internal QuadrantInfo this[Coordinates coordinate] => _quadrants[coordinate.X][coordinate.Y];
-
-        internal int KlingonCount => _quadrants.SelectMany(q => q).Sum(q => q.KlingonCount);
-
-        internal int StarbaseCount => _quadrants.SelectMany(q => q).Count(q => q.HasStarbase);
-
-        internal IEnumerable<IEnumerable<QuadrantInfo>> Quadrants => _quadrants;
-
-        private static string GetQuadrantName(Coordinates coordinates) =>
-            $"{_regionNames[coordinates.RegionIndex]} {_subRegionIdentifiers[coordinates.SubRegionIndex]}";
-
-        internal IEnumerable<IEnumerable<QuadrantInfo>> GetNeighborhood(Quadrant quadrant) =>
-            Enumerable.Range(-1, 3)
-                .Select(dx => dx + quadrant.Coordinates.X)
-                .Select(x => GetNeighborhoodRow(quadrant, x));
-        private IEnumerable<QuadrantInfo> GetNeighborhoodRow(Quadrant quadrant, int x) =>
-            Enumerable.Range(-1, 3)
-                .Select(dy => dy + quadrant.Coordinates.Y)
-                .Select(y => y < 0 || y > 7 || x < 0 || x > 7 ? null : _quadrants[x][y]);
    }
+
+    internal QuadrantInfo this[Coordinates coordinate] => _quadrants[coordinate.X][coordinate.Y];
+
+    internal int KlingonCount => _quadrants.SelectMany(q => q).Sum(q => q.KlingonCount);
+
+    internal int StarbaseCount => _quadrants.SelectMany(q => q).Count(q => q.HasStarbase);
+
+    internal IEnumerable<IEnumerable<QuadrantInfo>> Quadrants => _quadrants;
+
+    private static string GetQuadrantName(Coordinates coordinates) =>
+        $"{_regionNames[coordinates.RegionIndex]} {_subRegionIdentifiers[coordinates.SubRegionIndex]}";
+
+    internal IEnumerable<IEnumerable<QuadrantInfo>> GetNeighborhood(Quadrant quadrant) =>
+        Enumerable.Range(-1, 3)
+            .Select(dx => dx + quadrant.Coordinates.X)
+            .Select(x => GetNeighborhoodRow(quadrant, x));
+    private IEnumerable<QuadrantInfo> GetNeighborhoodRow(Quadrant quadrant, int x) =>
+        Enumerable.Range(-1, 3)
+            .Select(dy => dy + quadrant.Coordinates.Y)
+            .Select(y => y < 0 || y > 7 || x < 0 || x > 7 ? null : _quadrants[x][y]);
 }
--- a/84_Super_Star_Trek/csharp/Space/Quadrant.cs
+++ b/84_Super_Star_Trek/csharp/Space/Quadrant.cs
@@ -1,192 +1,192 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
+using Games.Common.Randomness;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;

-namespace SuperStarTrek.Space
+namespace SuperStarTrek.Space;
+
+internal class Quadrant
 {
-    internal class Quadrant
+    private readonly QuadrantInfo _info;
+    private readonly IRandom _random;
+    private readonly Dictionary<Coordinates, object> _sectors;
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+    private bool _entered = false;
+
+    internal Quadrant(
+        QuadrantInfo info,
+        Enterprise enterprise,
+        IRandom random,
+        Galaxy galaxy,
+        IReadWrite io)
    {
-        private readonly QuadrantInfo _info;
-        private readonly Random _random;
-        private readonly Dictionary<Coordinates, object> _sectors;
-        private readonly Enterprise _enterprise;
-        private readonly Output _output;
-        private bool _entered = false;
+        _info = info;
+        _random = random;
+        _io = io;
+        Galaxy = galaxy;

-        internal Quadrant(
-            QuadrantInfo info,
-            Enterprise enterprise,
-            Random random,
-            Galaxy galaxy,
-            Input input,
-            Output output)
+        info.MarkAsKnown();
+        _sectors = new() { [enterprise.SectorCoordinates] = _enterprise = enterprise };
+        PositionObject(sector => new Klingon(sector, _random), _info.KlingonCount);
+        if (_info.HasStarbase)
        {
-            _info = info;
-            _random = random;
-            _output = output;
-            Galaxy = galaxy;
+            Starbase = PositionObject(sector => new Starbase(sector, _random, io));
+        }
+        PositionObject(_ => new Star(), _info.StarCount);
+    }

-            info.MarkAsKnown();
-            _sectors = new() { [enterprise.SectorCoordinates] = _enterprise = enterprise };
-            PositionObject(sector => new Klingon(sector, _random), _info.KlingonCount);
-            if (_info.HasStarbase)
-            {
-                Starbase = PositionObject(sector => new Starbase(sector, _random, input, output));
-            }
-            PositionObject(_ => new Star(), _info.StarCount);
+    internal Coordinates Coordinates => _info.Coordinates;
+
+    internal bool HasKlingons => _info.KlingonCount > 0;
+
+    internal int KlingonCount => _info.KlingonCount;
+
+    internal bool HasStarbase => _info.HasStarbase;
+
+    internal Starbase Starbase { get; }
+
+    internal Galaxy Galaxy { get; }
+
+    internal bool EnterpriseIsNextToStarbase =>
+        _info.HasStarbase &&
+        Math.Abs(_enterprise.SectorCoordinates.X - Starbase.Sector.X) <= 1 &&
+        Math.Abs(_enterprise.SectorCoordinates.Y - Starbase.Sector.Y) <= 1;
+
+    internal IEnumerable<Klingon> Klingons => _sectors.Values.OfType<Klingon>();
+
+    public override string ToString() => _info.Name;
+
+    private T PositionObject<T>(Func<Coordinates, T> objectFactory)
+    {
+        var sector = GetRandomEmptySector();
+        _sectors[sector] = objectFactory.Invoke(sector);
+        return (T)_sectors[sector];
+    }
+
+    private void PositionObject(Func<Coordinates, object> objectFactory, int count)
+    {
+        for (int i = 0; i < count; i++)
+        {
+            PositionObject(objectFactory);
+        }
+    }
+
+    internal void Display(string textFormat)
+    {
+        if (!_entered)
+        {
+            _io.Write(textFormat, this);
+            _entered = true;
        }

-        internal Coordinates Coordinates => _info.Coordinates;
-
-        internal bool HasKlingons => _info.KlingonCount > 0;
-
-        internal int KlingonCount => _info.KlingonCount;
-
-        internal bool HasStarbase => _info.HasStarbase;
-
-        internal Starbase Starbase { get; }
-
-        internal Galaxy Galaxy { get; }
-
-        internal bool EnterpriseIsNextToStarbase =>
-            _info.HasStarbase &&
-            Math.Abs(_enterprise.SectorCoordinates.X - Starbase.Sector.X) <= 1 &&
-            Math.Abs(_enterprise.SectorCoordinates.Y - Starbase.Sector.Y) <= 1;
-
-        internal IEnumerable<Klingon> Klingons => _sectors.Values.OfType<Klingon>();
-
-        public override string ToString() => _info.Name;
-
-        private T PositionObject<T>(Func<Coordinates, T> objectFactory)
+        if (_info.KlingonCount > 0)
        {
-            var sector = GetRandomEmptySector();
-            _sectors[sector] = objectFactory.Invoke(sector);
-            return (T)_sectors[sector];
+            _io.Write(Strings.CombatArea);
+            if (_enterprise.ShieldControl.ShieldEnergy <= 200) { _io.Write(Strings.LowShields); }
        }

-        private void PositionObject(Func<Coordinates, object> objectFactory, int count)
+        _enterprise.Execute(Command.SRS);
+    }
+
+    internal bool HasObjectAt(Coordinates coordinates) => _sectors.ContainsKey(coordinates);
+
+    internal bool TorpedoCollisionAt(Coordinates coordinates, out string message, out bool gameOver)
+    {
+        gameOver = false;
+        message = default;
+
+        switch (_sectors.GetValueOrDefault(coordinates))
        {
-            for (int i = 0; i < count; i++)
-            {
-                PositionObject(objectFactory);
-            }
+            case Klingon klingon:
+                message = Remove(klingon);
+                gameOver = Galaxy.KlingonCount == 0;
+                return true;
+
+            case Star _:
+                message = $"Star at {coordinates} absorbed torpedo energy.";
+                return true;
+
+            case Starbase _:
+                _sectors.Remove(coordinates);
+                _info.RemoveStarbase();
+                message = "*** Starbase destroyed ***" +
+                    (Galaxy.StarbaseCount > 0 ? Strings.CourtMartial : Strings.RelievedOfCommand);
+                gameOver = Galaxy.StarbaseCount == 0;
+                return true;
+
+            default:
+                return false;
        }
+    }

-        internal void Display(string textFormat)
-        {
-            if (!_entered)
-            {
-                _output.Write(textFormat, this);
-                _entered = true;
-            }
-
-            if (_info.KlingonCount > 0)
-            {
-                _output.Write(Strings.CombatArea);
-                if (_enterprise.ShieldControl.ShieldEnergy <= 200) { _output.Write(Strings.LowShields); }
-            }
-
-            _enterprise.Execute(Command.SRS);
-        }
-
-        internal bool HasObjectAt(Coordinates coordinates) => _sectors.ContainsKey(coordinates);
-
-        internal bool TorpedoCollisionAt(Coordinates coordinates, out string message, out bool gameOver)
-        {
-            gameOver = false;
-            message = default;
-
-            switch (_sectors.GetValueOrDefault(coordinates))
-            {
-                case Klingon klingon:
-                    message = Remove(klingon);
-                    gameOver = Galaxy.KlingonCount == 0;
-                    return true;
-
-                case Star _:
-                    message = $"Star at {coordinates} absorbed torpedo energy.";
-                    return true;
-
-                case Starbase _:
-                    _sectors.Remove(coordinates);
-                    _info.RemoveStarbase();
-                    message = "*** Starbase destroyed ***" +
-                        (Galaxy.StarbaseCount > 0 ? Strings.CourtMartial : Strings.RelievedOfCommand);
-                    gameOver = Galaxy.StarbaseCount == 0;
-                    return true;
-
-                default:
-                    return false;
-            }
-        }
-
-        internal string Remove(Klingon klingon)
+    internal string Remove(Klingon klingon)
+    {
+        _sectors.Remove(klingon.Sector);
+        _info.RemoveKlingon();
+        return "*** Klingon destroyed ***";
+    }
+
+    internal CommandResult KlingonsMoveAndFire()
+    {
+        foreach (var klingon in Klingons.ToList())
        {
+            var newSector = GetRandomEmptySector();
            _sectors.Remove(klingon.Sector);
-            _info.RemoveKlingon();
-            return "*** Klingon destroyed ***";
+            _sectors[newSector] = klingon;
+            klingon.MoveTo(newSector);
        }

-        internal CommandResult KlingonsMoveAndFire()
+        return KlingonsFireOnEnterprise();
+    }
+
+    internal CommandResult KlingonsFireOnEnterprise()
+    {
+        if (EnterpriseIsNextToStarbase && Klingons.Any())
        {
-            foreach (var klingon in Klingons.ToList())
-            {
-                var newSector = GetRandomEmptySector();
-                _sectors.Remove(klingon.Sector);
-                _sectors[newSector] = klingon;
-                klingon.MoveTo(newSector);
-            }
-
-            return KlingonsFireOnEnterprise();
-        }
-
-        internal CommandResult KlingonsFireOnEnterprise()
-        {
-            if (EnterpriseIsNextToStarbase && Klingons.Any())
-            {
-                Starbase.ProtectEnterprise();
-                return CommandResult.Ok;
-            }
-
-            foreach (var klingon in Klingons)
-            {
-                var result = klingon.FireOn(_enterprise);
-                if (result.IsGameOver) { return result; }
-            }
-
+            Starbase.ProtectEnterprise();
            return CommandResult.Ok;
        }

-        private Coordinates GetRandomEmptySector()
+        foreach (var klingon in Klingons)
        {
-            while (true)
+            var result = klingon.FireOn(_enterprise);
+            if (result.IsGameOver) { return result; }
+        }
+
+        return CommandResult.Ok;
+    }
+
+    private Coordinates GetRandomEmptySector()
+    {
+        while (true)
+        {
+            var sector = _random.NextCoordinate();
+            if (!_sectors.ContainsKey(sector))
            {
-                var sector = _random.GetCoordinate();
-                if (!_sectors.ContainsKey(sector))
-                {
-                    return sector;
-                }
+                return sector;
            }
        }
+    }

-        internal IEnumerable<string> GetDisplayLines() => Enumerable.Range(0, 8).Select(x => GetDisplayLine(x));
+    internal IEnumerable<string> GetDisplayLines() => Enumerable.Range(0, 8).Select(x => GetDisplayLine(x));

-        private string GetDisplayLine(int x) =>
-            string.Join(
-                " ",
-                Enumerable
-                    .Range(0, 8)
-                    .Select(y => new Coordinates(x, y))
-                    .Select(c => _sectors.GetValueOrDefault(c))
-                    .Select(o => o?.ToString() ?? "   "));
+    private string GetDisplayLine(int x) =>
+        string.Join(
+            " ",
+            Enumerable
+                .Range(0, 8)
+                .Select(y => new Coordinates(x, y))
+                .Select(c => _sectors.GetValueOrDefault(c))
+                .Select(o => o?.ToString() ?? "   "));

-        internal void SetEnterpriseSector(Coordinates sector)
-        {
-            _sectors.Remove(_enterprise.SectorCoordinates);
-            _sectors[sector] = _enterprise;
-        }
+    internal void SetEnterpriseSector(Coordinates sector)
+    {
+        _sectors.Remove(_enterprise.SectorCoordinates);
+        _sectors[sector] = _enterprise;
    }
 }
--- a/84_Super_Star_Trek/csharp/Space/QuadrantInfo.cs
+++ b/84_Super_Star_Trek/csharp/Space/QuadrantInfo.cs
@@ -1,65 +1,66 @@
-namespace SuperStarTrek.Space
+using Games.Common.Randomness;
+
+namespace SuperStarTrek.Space;
+
+internal class QuadrantInfo
 {
-    internal class QuadrantInfo
+    private bool _isKnown;
+
+    private QuadrantInfo(Coordinates coordinates, string name, int klingonCount, int starCount, bool hasStarbase)
    {
-        private bool _isKnown;
-
-        private QuadrantInfo(Coordinates coordinates, string name, int klingonCount, int starCount, bool hasStarbase)
-        {
-            Coordinates = coordinates;
-            Name = name;
-            KlingonCount = klingonCount;
-            StarCount = starCount;
-            HasStarbase = hasStarbase;
-        }
-
-        internal Coordinates Coordinates { get; }
-
-        internal string Name { get; }
-
-        internal int KlingonCount { get; private set; }
-
-        internal bool HasStarbase { get; private set; }
-
-        internal int StarCount { get; }
-
-        internal static QuadrantInfo Create(Coordinates coordinates, string name, Random random)
-        {
-            var klingonCount = random.GetFloat() switch
-            {
-                > 0.98f => 3,
-                > 0.95f => 2,
-                > 0.80f => 1,
-                _ => 0
-            };
-            var hasStarbase = random.GetFloat() > 0.96f;
-            var starCount = random.Get1To8Inclusive();
-
-            return new QuadrantInfo(coordinates, name, klingonCount, starCount, hasStarbase);
-        }
-
-        internal void AddKlingon() => KlingonCount += 1;
-
-        internal void AddStarbase() => HasStarbase = true;
-
-        internal void MarkAsKnown() => _isKnown = true;
-
-        internal string Scan()
-        {
-            _isKnown = true;
-            return ToString();
-        }
-
-        public override string ToString() => _isKnown ? $"{KlingonCount}{(HasStarbase ? 1 : 0)}{StarCount}" : "***";
-
-        internal void RemoveKlingon()
-        {
-            if (KlingonCount > 0)
-            {
-                KlingonCount -= 1;
-            }
-        }
-
-        internal void RemoveStarbase() => HasStarbase = false;
+        Coordinates = coordinates;
+        Name = name;
+        KlingonCount = klingonCount;
+        StarCount = starCount;
+        HasStarbase = hasStarbase;
    }
+
+    internal Coordinates Coordinates { get; }
+
+    internal string Name { get; }
+
+    internal int KlingonCount { get; private set; }
+
+    internal bool HasStarbase { get; private set; }
+
+    internal int StarCount { get; }
+
+    internal static QuadrantInfo Create(Coordinates coordinates, string name, IRandom random)
+    {
+        var klingonCount = random.NextFloat() switch
+        {
+            > 0.98f => 3,
+            > 0.95f => 2,
+            > 0.80f => 1,
+            _ => 0
+        };
+        var hasStarbase = random.NextFloat() > 0.96f;
+        var starCount = random.Next1To8Inclusive();
+
+        return new QuadrantInfo(coordinates, name, klingonCount, starCount, hasStarbase);
+    }
+
+    internal void AddKlingon() => KlingonCount += 1;
+
+    internal void AddStarbase() => HasStarbase = true;
+
+    internal void MarkAsKnown() => _isKnown = true;
+
+    internal string Scan()
+    {
+        _isKnown = true;
+        return ToString();
+    }
+
+    public override string ToString() => _isKnown ? $"{KlingonCount}{(HasStarbase ? 1 : 0)}{StarCount}" : "***";
+
+    internal void RemoveKlingon()
+    {
+        if (KlingonCount > 0)
+        {
+            KlingonCount -= 1;
+        }
+    }
+
+    internal void RemoveStarbase() => HasStarbase = false;
 }
--- a/84_Super_Star_Trek/csharp/StringExtensions.cs
+++ b/84_Super_Star_Trek/csharp/StringExtensions.cs
@@ -1,7 +1,6 @@
-namespace SuperStarTrek
+namespace SuperStarTrek;
+
+internal static class StringExtensions
 {
-    internal static class StringExtensions
-    {
-        internal static string Pluralize(this string singular, int quantity) => singular + (quantity > 1 ? "s" : "");
-    }
+    internal static string Pluralize(this string singular, int quantity) => singular + (quantity > 1 ? "s" : "");
 }
--- a/84_Super_Star_Trek/csharp/SuperStarTrek.csproj
+++ b/84_Super_Star_Trek/csharp/SuperStarTrek.csproj
@@ -2,11 +2,15 @@

  <PropertyGroup>
    <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <EmbeddedResource Include="Resources\*.txt" />
  </ItemGroup>

+  <ItemGroup>
+    <ProjectReference Include="..\..\00_Common\dotnet\Games.Common\Games.Common.csproj" />
+  </ItemGroup>
+
 </Project>
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/ComputerFunction.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/ComputerFunction.cs
@@ -1,19 +1,19 @@
+using Games.Common.IO;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal abstract class ComputerFunction
 {
-    internal abstract class ComputerFunction
+    protected ComputerFunction(string description, IReadWrite io)
    {
-        protected ComputerFunction(string description, Output output)
-        {
-            Description = description;
-            Output = output;
-        }
-
-        internal string Description { get; }
-
-        protected Output Output { get; }
-
-        internal abstract void Execute(Quadrant quadrant);
+        Description = description;
+        IO = io;
    }
+
+    internal string Description { get; }
+
+    protected IReadWrite IO { get; }
+
+    internal abstract void Execute(Quadrant quadrant);
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/CumulativeGalacticRecord.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/CumulativeGalacticRecord.cs
@@ -1,21 +1,24 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal class CumulativeGalacticRecord : GalacticReport
 {
-    internal class CumulativeGalacticRecord : GalacticReport
+    internal CumulativeGalacticRecord(IReadWrite io, Galaxy galaxy)
+        : base("Cumulative galactic record", io, galaxy)
    {
-        internal CumulativeGalacticRecord(Output output, Galaxy galaxy)
-            : base("Cumulative galactic record", output, galaxy)
-        {
-        }
-
-        protected override void WriteHeader(Quadrant quadrant) =>
-            Output.NextLine().WriteLine($"Computer record of galaxy for quadrant {quadrant.Coordinates}").NextLine();
-
-        protected override IEnumerable<string> GetRowData() =>
-            Galaxy.Quadrants.Select(row => " " + string.Join("   ", row));
    }
+
+    protected override void WriteHeader(Quadrant quadrant)
+    {
+        IO.WriteLine();
+        IO.WriteLine($"Computer record of galaxy for quadrant {quadrant.Coordinates}");
+        IO.WriteLine();
+    }
+
+    protected override IEnumerable<string> GetRowData() =>
+        Galaxy.Quadrants.Select(row => " " + string.Join("   ", row));
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/DirectionDistanceCalculator.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/DirectionDistanceCalculator.cs
@@ -1,30 +1,30 @@
+using Games.Common.IO;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal class DirectionDistanceCalculator : NavigationCalculator
 {
-    internal class DirectionDistanceCalculator : NavigationCalculator
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+
+    internal DirectionDistanceCalculator(Enterprise enterprise, IReadWrite io)
+        : base("Direction/distance calculator", io)
    {
-        private readonly Enterprise _enterprise;
-        private readonly Input _input;
+        _enterprise = enterprise;
+        _io = io;
+    }

-        internal DirectionDistanceCalculator(Enterprise enterprise, Output output, Input input)
-            : base("Direction/distance calculator", output)
-        {
-            _enterprise = enterprise;
-            _input = input;
-        }
+    internal override void Execute(Quadrant quadrant)
+    {
+        IO.WriteLine("Direction/distance calculator:");
+        IO.Write($"You are at quadrant {_enterprise.QuadrantCoordinates}");
+        IO.WriteLine($" sector {_enterprise.SectorCoordinates}");
+        IO.WriteLine("Please enter");

-        internal override void Execute(Quadrant quadrant)
-        {
-            Output.WriteLine("Direction/distance calculator:")
-                .Write($"You are at quadrant {_enterprise.QuadrantCoordinates}")
-                .WriteLine($" sector {_enterprise.SectorCoordinates}")
-                .WriteLine("Please enter");
-
-            WriteDirectionAndDistance(
-                _input.GetCoordinates("  Initial coordinates"),
-                _input.GetCoordinates("  Final coordinates"));
-        }
+        WriteDirectionAndDistance(
+            _io.GetCoordinates("  Initial coordinates"),
+            _io.GetCoordinates("  Final coordinates"));
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/GalacticReport.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/GalacticReport.cs
@@ -1,34 +1,34 @@
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal abstract class GalacticReport : ComputerFunction
 {
-    internal abstract class GalacticReport : ComputerFunction
+    internal GalacticReport(string description, IReadWrite io, Galaxy galaxy)
+        : base(description, io)
    {
-        internal GalacticReport(string description, Output output, Galaxy galaxy)
-            : base(description, output)
+        Galaxy = galaxy;
+    }
+
+    protected Galaxy Galaxy { get; }
+
+    protected abstract void WriteHeader(Quadrant quadrant);
+
+    protected abstract IEnumerable<string> GetRowData();
+
+    internal sealed override void Execute(Quadrant quadrant)
+    {
+        WriteHeader(quadrant);
+        IO.WriteLine("       1     2     3     4     5     6     7     8");
+        IO.WriteLine("     ----- ----- ----- ----- ----- ----- ----- -----");
+
+        foreach (var (row, index) in GetRowData().Select((r, i) => (r, i)))
        {
-            Galaxy = galaxy;
-        }
-
-        protected Galaxy Galaxy { get; }
-
-        protected abstract void WriteHeader(Quadrant quadrant);
-
-        protected abstract IEnumerable<string> GetRowData();
-
-        internal sealed override void Execute(Quadrant quadrant)
-        {
-            WriteHeader(quadrant);
-            Output.WriteLine("       1     2     3     4     5     6     7     8")
-                .WriteLine("     ----- ----- ----- ----- ----- ----- ----- -----");
-
-            foreach (var (row, index) in GetRowData().Select((r, i) => (r, i)))
-            {
-                Output.WriteLine($" {index+1}   {row}")
-                    .WriteLine("     ----- ----- ----- ----- ----- ----- ----- -----");
-            }
+            IO.WriteLine($" {index+1}   {row}");
+            IO.WriteLine("     ----- ----- ----- ----- ----- ----- ----- -----");
        }
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/GalaxyRegionMap.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/GalaxyRegionMap.cs
@@ -1,21 +1,21 @@
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal class GalaxyRegionMap : GalacticReport
 {
-    internal class GalaxyRegionMap : GalacticReport
+    internal GalaxyRegionMap(IReadWrite io, Galaxy galaxy)
+        : base("Galaxy 'region name' map", io, galaxy)
    {
-        internal GalaxyRegionMap(Output output, Galaxy galaxy)
-            : base("Galaxy 'region name' map", output, galaxy)
-        {
-        }
-
-        protected override void WriteHeader(Quadrant quadrant) =>
-            Output.WriteLine("                        The Galaxy");
-
-        protected override IEnumerable<string> GetRowData() =>
-            Strings.RegionNames.Split('\n').Select(n => n.TrimEnd('\r'));
    }
+
+    protected override void WriteHeader(Quadrant quadrant) =>
+        IO.WriteLine("                        The Galaxy");
+
+    protected override IEnumerable<string> GetRowData() =>
+        Strings.RegionNames.Split('\n').Select(n => n.TrimEnd('\r'));
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/NavigationCalculator.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/NavigationCalculator.cs
@@ -1,29 +1,31 @@
+using Games.Common.IO;
 using SuperStarTrek.Space;
 using SuperStarTrek.Utils;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal abstract class NavigationCalculator : ComputerFunction
 {
-    internal abstract class NavigationCalculator : ComputerFunction
+    protected NavigationCalculator(string description, IReadWrite io)
+        : base(description, io)
    {
-        protected NavigationCalculator(string description, Output output)
-            : base(description, output)
-        {
-        }
+    }

-        protected void WriteDirectionAndDistance(Coordinates from, Coordinates to)
-        {
-            var (direction, distance) = from.GetDirectionAndDistanceTo(to);
-            Write(direction, distance);
-        }
+    protected void WriteDirectionAndDistance(Coordinates from, Coordinates to)
+    {
+        var (direction, distance) = from.GetDirectionAndDistanceTo(to);
+        Write(direction, distance);
+    }

-        protected void WriteDirectionAndDistance((float X, float Y) from, (float X, float Y) to)
-        {
-            var (direction, distance) = DirectionAndDistance.From(from.X, from.Y).To(to.X, to.Y);
-            Write(direction, distance);
-        }
+    protected void WriteDirectionAndDistance((float X, float Y) from, (float X, float Y) to)
+    {
+        var (direction, distance) = DirectionAndDistance.From(from.X, from.Y).To(to.X, to.Y);
+        Write(direction, distance);
+    }

-        private void Write(float direction, float distance) =>
-            Output.WriteLine($"Direction = {direction}")
-                .WriteLine($"Distance = {distance}");
+    private void Write(float direction, float distance)
+    {
+        IO.WriteLine($"Direction = {direction}");
+        IO.WriteLine($"Distance = {distance}");
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/StarbaseDataCalculator.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/StarbaseDataCalculator.cs
@@ -1,30 +1,30 @@
+using Games.Common.IO;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal class StarbaseDataCalculator : NavigationCalculator
 {
-    internal class StarbaseDataCalculator : NavigationCalculator
+    private readonly Enterprise _enterprise;
+
+    internal StarbaseDataCalculator(Enterprise enterprise, IReadWrite io)
+        : base("Starbase nav data", io)
    {
-        private readonly Enterprise _enterprise;
+        _enterprise = enterprise;
+    }

-        internal StarbaseDataCalculator(Enterprise enterprise, Output output)
-            : base("Starbase nav data", output)
+    internal override void Execute(Quadrant quadrant)
+    {
+        if (!quadrant.HasStarbase)
        {
-            _enterprise = enterprise;
+            IO.WriteLine(Strings.NoStarbase);
+            return;
        }

-        internal override void Execute(Quadrant quadrant)
-        {
-            if (!quadrant.HasStarbase)
-            {
-                Output.WriteLine(Strings.NoStarbase);
-                return;
-            }
+        IO.WriteLine("From Enterprise to Starbase:");

-            Output.WriteLine("From Enterprise to Starbase:");
-
-            WriteDirectionAndDistance(_enterprise.SectorCoordinates, quadrant.Starbase.Sector);
-        }
+        WriteDirectionAndDistance(_enterprise.SectorCoordinates, quadrant.Starbase.Sector);
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/StatusReport.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/StatusReport.cs
@@ -1,41 +1,43 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
+namespace SuperStarTrek.Systems.ComputerFunctions;
+
+internal class StatusReport : ComputerFunction
 {
-    internal class StatusReport : ComputerFunction
+    private readonly Game _game;
+    private readonly Galaxy _galaxy;
+    private readonly Enterprise _enterprise;
+
+    internal StatusReport(Game game, Galaxy galaxy, Enterprise enterprise, IReadWrite io)
+        : base("Status report", io)
    {
-        private readonly Game _game;
-        private readonly Galaxy _galaxy;
-        private readonly Enterprise _enterprise;
+        _game = game;
+        _galaxy = galaxy;
+        _enterprise = enterprise;
+    }

-        internal StatusReport(Game game, Galaxy galaxy, Enterprise enterprise, Output output)
-            : base("Status report", output)
+    internal override void Execute(Quadrant quadrant)
+    {
+        IO.WriteLine("   Status report:");
+        IO.Write("Klingon".Pluralize(_galaxy.KlingonCount));
+        IO.WriteLine($" left:  {_galaxy.KlingonCount}");
+        IO.WriteLine($"Mission must be completed in {_game.StardatesRemaining:0.#} stardates.");
+
+        if (_galaxy.StarbaseCount > 0)
        {
-            _game = game;
-            _galaxy = galaxy;
-            _enterprise = enterprise;
+            IO.Write($"The Federation is maintaining {_galaxy.StarbaseCount} ");
+            IO.Write("starbase".Pluralize(_galaxy.StarbaseCount));
+            IO.WriteLine(" in the galaxy.");
+        }
+        else
+        {
+            IO.WriteLine("Your stupidity has left you on your own in");
+            IO.WriteLine("  the galaxy -- you have no starbases left!");
        }

-        internal override void Execute(Quadrant quadrant)
-        {
-            Output.WriteLine("   Status report:")
-                .Write("Klingon".Pluralize(_galaxy.KlingonCount)).WriteLine($" left:  {_galaxy.KlingonCount}")
-                .WriteLine($"Mission must be completed in {_game.StardatesRemaining:0.#} stardates.");
-
-            if (_galaxy.StarbaseCount > 0)
-            {
-                Output.Write($"The Federation is maintaining {_galaxy.StarbaseCount} ")
-                   .Write("starbase".Pluralize(_galaxy.StarbaseCount)).WriteLine(" in the galaxy.");
-            }
-            else
-            {
-                Output.WriteLine("Your stupidity has left you on your own in")
-                    .WriteLine("  the galaxy -- you have no starbases left!");
-            }
-
-            _enterprise.Execute(Command.DAM);
-        }
+        _enterprise.Execute(Command.DAM);
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/TorpedoDataCalculator.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ComputerFunctions/TorpedoDataCalculator.cs
@@ -1,33 +1,33 @@
+using Games.Common.IO;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems.ComputerFunctions
-{
-    internal class TorpedoDataCalculator : NavigationCalculator
-    {
-        private readonly Enterprise _enterprise;
+namespace SuperStarTrek.Systems.ComputerFunctions;

-        internal TorpedoDataCalculator(Enterprise enterprise, Output output)
-            : base("Photon torpedo data", output)
+internal class TorpedoDataCalculator : NavigationCalculator
+{
+    private readonly Enterprise _enterprise;
+
+    internal TorpedoDataCalculator(Enterprise enterprise, IReadWrite io)
+        : base("Photon torpedo data", io)
+    {
+        _enterprise = enterprise;
+    }
+
+    internal override void Execute(Quadrant quadrant)
+    {
+        if (!quadrant.HasKlingons)
        {
-            _enterprise = enterprise;
+            IO.WriteLine(Strings.NoEnemyShips);
+            return;
        }

-        internal override void Execute(Quadrant quadrant)
+        IO.WriteLine("From Enterprise to Klingon battle cruiser".Pluralize(quadrant.KlingonCount));
+
+        foreach (var klingon in quadrant.Klingons)
        {
-            if (!quadrant.HasKlingons)
-            {
-                Output.WriteLine(Strings.NoEnemyShips);
-                return;
-            }
-
-            Output.WriteLine("From Enterprise to Klingon battle cruiser".Pluralize(quadrant.KlingonCount));
-
-            foreach (var klingon in quadrant.Klingons)
-            {
-                WriteDirectionAndDistance(_enterprise.SectorCoordinates, klingon.Sector);
-            }
+            WriteDirectionAndDistance(_enterprise.SectorCoordinates, klingon.Sector);
        }
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/DamageControl.cs
+++ b/84_Super_Star_Trek/csharp/Systems/DamageControl.cs
@@ -1,54 +1,55 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class DamageControl : Subsystem
 {
-    internal class DamageControl : Subsystem
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+
+    internal DamageControl(Enterprise enterprise, IReadWrite io)
+        : base("Damage Control", Command.DAM, io)
    {
-        private readonly Enterprise _enterprise;
-        private readonly Output _output;
+        _enterprise = enterprise;
+        _io = io;
+    }

-        internal DamageControl(Enterprise enterprise, Output output)
-            : base("Damage Control", Command.DAM, output)
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        if (IsDamaged)
        {
-            _enterprise = enterprise;
-            _output = output;
+            _io.WriteLine("Damage Control report not available");
+        }
+        else
+        {
+            _io.WriteLine();
+            WriteDamageReport();
        }

-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+        if (_enterprise.DamagedSystemCount > 0 && _enterprise.IsDocked)
        {
-            if (IsDamaged)
+            if (quadrant.Starbase.TryRepair(_enterprise, out var repairTime))
            {
-                _output.WriteLine("Damage Control report not available");
-            }
-            else
-            {
-                _output.NextLine();
                WriteDamageReport();
+                return CommandResult.Elapsed(repairTime);
            }
-
-            if (_enterprise.DamagedSystemCount > 0 && _enterprise.IsDocked)
-            {
-                if (quadrant.Starbase.TryRepair(_enterprise, out var repairTime))
-                {
-                    WriteDamageReport();
-                    return CommandResult.Elapsed(repairTime);
-                }
-            }
-
-            return CommandResult.Ok;
        }

-        internal void WriteDamageReport()
+        return CommandResult.Ok;
+    }
+
+    internal void WriteDamageReport()
+    {
+        _io.WriteLine();
+        _io.WriteLine("Device             State of Repair");
+        foreach (var system in _enterprise.Systems)
        {
-            _output.NextLine().WriteLine("Device             State of Repair");
-            foreach (var system in _enterprise.Systems)
-            {
-                _output.Write(system.Name.PadRight(25))
-                    .WriteLine(((int)(system.Condition * 100) * 0.01).ToString(" 0.##;-0.##"));
-            }
-            _output.NextLine();
+            _io.Write(system.Name.PadRight(25));
+            _io.WriteLine((int)(system.Condition * 100) * 0.01F);
        }
+        _io.WriteLine();
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/LibraryComputer.cs
+++ b/84_Super_Star_Trek/csharp/Systems/LibraryComputer.cs
@@ -1,46 +1,44 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Space;
 using SuperStarTrek.Systems.ComputerFunctions;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class LibraryComputer : Subsystem
 {
-    internal class LibraryComputer : Subsystem
+    private readonly IReadWrite _io;
+    private readonly ComputerFunction[] _functions;
+
+    internal LibraryComputer(IReadWrite io, params ComputerFunction[] functions)
+        : base("Library-Computer", Command.COM, io)
    {
-        private readonly Output _output;
-        private readonly Input _input;
-        private readonly ComputerFunction[] _functions;
+        _io = io;
+        _functions = functions;
+    }

-        internal LibraryComputer(Output output, Input input, params ComputerFunction[] functions)
-            : base("Library-Computer", Command.COM, output)
+    protected override bool CanExecuteCommand() => IsOperational("Computer disabled");
+
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        var index = GetFunctionIndex();
+        _io.WriteLine();
+
+        _functions[index].Execute(quadrant);
+
+        return CommandResult.Ok;
+    }
+
+    private int GetFunctionIndex()
+    {
+        while (true)
        {
-            _output = output;
-            _input = input;
-            _functions = functions;
-        }
+            var index = (int)_io.ReadNumber("Computer active and waiting command");
+            if (index >= 0 && index <= 5) { return index; }

-        protected override bool CanExecuteCommand() => IsOperational("Computer disabled");
-
-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
-        {
-            var index = GetFunctionIndex();
-            _output.NextLine();
-
-            _functions[index].Execute(quadrant);
-
-            return CommandResult.Ok;
-        }
-
-        private int GetFunctionIndex()
-        {
-            while (true)
+            for (int i = 0; i < _functions.Length; i++)
            {
-                var index = (int)_input.GetNumber("Computer active and waiting command");
-                if (index >= 0 && index <= 5) { return index; }
-
-                for (int i = 0; i < _functions.Length; i++)
-                {
-                    _output.WriteLine($"   {i} = {_functions[i].Description}");
-                }
+                _io.WriteLine($"   {i} = {_functions[i].Description}");
            }
        }
    }
--- a/84_Super_Star_Trek/csharp/Systems/LongRangeSensors.cs
+++ b/84_Super_Star_Trek/csharp/Systems/LongRangeSensors.cs
@@ -1,34 +1,35 @@
 using System.Linq;
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class LongRangeSensors : Subsystem
 {
-    internal class LongRangeSensors : Subsystem
+    private readonly Galaxy _galaxy;
+    private readonly IReadWrite _io;
+
+    internal LongRangeSensors(Galaxy galaxy, IReadWrite io)
+        : base("Long Range Sensors", Command.LRS, io)
    {
-        private readonly Galaxy _galaxy;
-        private readonly Output _output;
+        _galaxy = galaxy;
+        _io = io;
+    }

-        internal LongRangeSensors(Galaxy galaxy, Output output)
-            : base("Long Range Sensors", Command.LRS, output)
+    protected override bool CanExecuteCommand() => IsOperational("{name} are inoperable");
+
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        _io.WriteLine($"Long range scan for quadrant {quadrant.Coordinates}");
+        _io.WriteLine("-------------------");
+        foreach (var quadrants in _galaxy.GetNeighborhood(quadrant))
        {
-            _galaxy = galaxy;
-            _output = output;
+            _io.WriteLine(": " + string.Join(" : ", quadrants.Select(q => q?.Scan() ?? "***")) + " :");
+            _io.WriteLine("-------------------");
        }

-        protected override bool CanExecuteCommand() => IsOperational("{name} are inoperable");
-
-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
-        {
-            _output.WriteLine($"Long range scan for quadrant {quadrant.Coordinates}");
-            _output.WriteLine("-------------------");
-            foreach (var quadrants in _galaxy.GetNeighborhood(quadrant))
-            {
-                _output.WriteLine(": " + string.Join(" : ", quadrants.Select(q => q?.Scan() ?? "***")) + " :");
-                _output.WriteLine("-------------------");
-            }
-
-            return CommandResult.Ok;
-        }
+        return CommandResult.Ok;
    }
 }
+
--- a/84_Super_Star_Trek/csharp/Systems/PhaserControl.cs
+++ b/84_Super_Star_Trek/csharp/Systems/PhaserControl.cs
@@ -1,97 +1,96 @@
 using System.Linq;
+using Games.Common.IO;
+using Games.Common.Randomness;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class PhaserControl : Subsystem
 {
-    internal class PhaserControl : Subsystem
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+    private readonly IRandom _random;
+
+    internal PhaserControl(Enterprise enterprise, IReadWrite io, IRandom random)
+        : base("Phaser Control", Command.PHA, io)
    {
-        private readonly Enterprise _enterprise;
-        private readonly Output _output;
-        private readonly Input _input;
-        private readonly Random _random;
+        _enterprise = enterprise;
+        _io = io;
+        _random = random;
+    }

-        internal PhaserControl(Enterprise enterprise, Output output, Input input, Random random)
-            : base("Phaser Control", Command.PHA, output)
+    protected override bool CanExecuteCommand() => IsOperational("Phasers inoperative");
+
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        if (!quadrant.HasKlingons)
        {
-            _enterprise = enterprise;
-            _output = output;
-            _input = input;
-            _random = random;
+            _io.WriteLine(Strings.NoEnemyShips);
+            return CommandResult.Ok;
        }

-        protected override bool CanExecuteCommand() => IsOperational("Phasers inoperative");
-
-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+        if (_enterprise.Computer.IsDamaged)
        {
-            if (!quadrant.HasKlingons)
-            {
-                _output.WriteLine(Strings.NoEnemyShips);
-                return CommandResult.Ok;
-            }
-
-            if (_enterprise.Computer.IsDamaged)
-            {
-                _output.WriteLine("Computer failure hampers accuracy");
-            }
-
-            _output.Write($"Phasers locked on target;  ");
-
-            var phaserStrength = GetPhaserStrength();
-            if (phaserStrength < 0) { return CommandResult.Ok; }
-
-            _enterprise.UseEnergy(phaserStrength);
-
-            var perEnemyStrength = GetPerTargetPhaserStrength(phaserStrength, quadrant.KlingonCount);
-
-            foreach (var klingon in quadrant.Klingons.ToList())
-            {
-                ResolveHitOn(klingon, perEnemyStrength, quadrant);
-            }
-
-            return quadrant.KlingonsFireOnEnterprise();
+            _io.WriteLine("Computer failure hampers accuracy");
        }

-        private float GetPhaserStrength()
-        {
-            while (true)
-            {
-                _output.WriteLine($"Energy available = {_enterprise.Energy} units");
-                var phaserStrength = _input.GetNumber("Number of units to fire");
+        _io.Write($"Phasers locked on target;  ");

-                if (phaserStrength <= _enterprise.Energy) { return phaserStrength; }
-            }
+        var phaserStrength = GetPhaserStrength();
+        if (phaserStrength < 0) { return CommandResult.Ok; }
+
+        _enterprise.UseEnergy(phaserStrength);
+
+        var perEnemyStrength = GetPerTargetPhaserStrength(phaserStrength, quadrant.KlingonCount);
+
+        foreach (var klingon in quadrant.Klingons.ToList())
+        {
+            ResolveHitOn(klingon, perEnemyStrength, quadrant);
        }

-        private float GetPerTargetPhaserStrength(float phaserStrength, int targetCount)
-        {
-            if (_enterprise.Computer.IsDamaged)
-            {
-                phaserStrength *= _random.GetFloat();
-            }
+        return quadrant.KlingonsFireOnEnterprise();
+    }

-            return phaserStrength / targetCount;
+    private float GetPhaserStrength()
+    {
+        while (true)
+        {
+            _io.WriteLine($"Energy available = {_enterprise.Energy} units");
+            var phaserStrength = _io.ReadNumber("Number of units to fire");
+
+            if (phaserStrength <= _enterprise.Energy) { return phaserStrength; }
+        }
+    }
+
+    private float GetPerTargetPhaserStrength(float phaserStrength, int targetCount)
+    {
+        if (_enterprise.Computer.IsDamaged)
+        {
+            phaserStrength *= _random.NextFloat();
        }

-        private void ResolveHitOn(Klingon klingon, float perEnemyStrength, Quadrant quadrant)
-        {
-            var distance = _enterprise.SectorCoordinates.GetDistanceTo(klingon.Sector);
-            var hitStrength = (int)(perEnemyStrength / distance * (2 + _random.GetFloat()));
+        return phaserStrength / targetCount;
+    }

-            if (klingon.TakeHit(hitStrength))
-            {
-                _output.WriteLine($"{hitStrength} unit hit on Klingon at sector {klingon.Sector}");
-                _output.WriteLine(
-                    klingon.Energy <= 0
-                        ? quadrant.Remove(klingon)
-                        : $"   (sensors show {klingon.Energy} units remaining)");
-            }
-            else
-            {
-                _output.WriteLine($"Sensors show no damage to enemy at {klingon.Sector}");
-            }
+    private void ResolveHitOn(Klingon klingon, float perEnemyStrength, Quadrant quadrant)
+    {
+        var distance = _enterprise.SectorCoordinates.GetDistanceTo(klingon.Sector);
+        var hitStrength = (int)(perEnemyStrength / distance * (2 + _random.NextFloat()));
+
+        if (klingon.TakeHit(hitStrength))
+        {
+            _io.WriteLine($"{hitStrength} unit hit on Klingon at sector {klingon.Sector}");
+            _io.WriteLine(
+                klingon.Energy <= 0
+                    ? quadrant.Remove(klingon)
+                    : $"   (sensors show {klingon.Energy} units remaining)");
+        }
+        else
+        {
+            _io.WriteLine($"Sensors show no damage to enemy at {klingon.Sector}");
        }
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/PhotonTubes.cs
+++ b/84_Super_Star_Trek/csharp/Systems/PhotonTubes.cs
@@ -1,66 +1,64 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class PhotonTubes : Subsystem
 {
-    internal class PhotonTubes : Subsystem
+    private readonly int _tubeCount;
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+
+    internal PhotonTubes(int tubeCount, Enterprise enterprise, IReadWrite io)
+        : base("Photon Tubes", Command.TOR, io)
    {
-        private readonly int _tubeCount;
-        private readonly Enterprise _enterprise;
-        private readonly Output _output;
-        private readonly Input _input;
-
-        internal PhotonTubes(int tubeCount, Enterprise enterprise, Output output, Input input)
-            : base("Photon Tubes", Command.TOR, output)
-        {
-            TorpedoCount = _tubeCount = tubeCount;
-            _enterprise = enterprise;
-            _output = output;
-            _input = input;
-        }
-
-        internal int TorpedoCount { get; private set; }
-
-        protected override bool CanExecuteCommand() => HasTorpedoes() && IsOperational("{name} are not operational");
-
-        private bool HasTorpedoes()
-        {
-            if (TorpedoCount > 0) { return true; }
-
-            _output.WriteLine("All photon torpedoes expended");
-            return false;
-        }
-
-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
-        {
-            if (!_input.TryGetCourse("Photon torpedo course", "Ensign Chekov", out var course))
-            {
-                return CommandResult.Ok;
-            }
-
-            TorpedoCount -= 1;
-
-            var isHit = false;
-            _output.WriteLine("Torpedo track:");
-            foreach (var sector in course.GetSectorsFrom(_enterprise.SectorCoordinates))
-            {
-                _output.WriteLine($"                {sector}");
-
-                if (quadrant.TorpedoCollisionAt(sector, out var message, out var gameOver))
-                {
-                    _output.WriteLine(message);
-                    isHit = true;
-                    if (gameOver) { return CommandResult.GameOver; }
-                    break;
-                }
-            }
-
-            if (!isHit) { _output.WriteLine("Torpedo missed!"); }
-
-            return quadrant.KlingonsFireOnEnterprise();
-        }
-
-        internal void ReplenishTorpedoes() => TorpedoCount = _tubeCount;
+        TorpedoCount = _tubeCount = tubeCount;
+        _enterprise = enterprise;
+        _io = io;
    }
+
+    internal int TorpedoCount { get; private set; }
+
+    protected override bool CanExecuteCommand() => HasTorpedoes() && IsOperational("{name} are not operational");
+
+    private bool HasTorpedoes()
+    {
+        if (TorpedoCount > 0) { return true; }
+
+        _io.WriteLine("All photon torpedoes expended");
+        return false;
+    }
+
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        if (!_io.TryReadCourse("Photon torpedo course", "Ensign Chekov", out var course))
+        {
+            return CommandResult.Ok;
+        }
+
+        TorpedoCount -= 1;
+
+        var isHit = false;
+        _io.WriteLine("Torpedo track:");
+        foreach (var sector in course.GetSectorsFrom(_enterprise.SectorCoordinates))
+        {
+            _io.WriteLine($"                {sector}");
+
+            if (quadrant.TorpedoCollisionAt(sector, out var message, out var gameOver))
+            {
+                _io.WriteLine(message);
+                isHit = true;
+                if (gameOver) { return CommandResult.GameOver; }
+                break;
+            }
+        }
+
+        if (!isHit) { _io.WriteLine("Torpedo missed!"); }
+
+        return quadrant.KlingonsFireOnEnterprise();
+    }
+
+    internal void ReplenishTorpedoes() => TorpedoCount = _tubeCount;
 }
--- a/84_Super_Star_Trek/csharp/Systems/ShieldControl.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ShieldControl.cs
@@ -1,59 +1,57 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class ShieldControl : Subsystem
 {
-    internal class ShieldControl : Subsystem
+    private readonly Enterprise _enterprise;
+    private readonly IReadWrite _io;
+
+    internal ShieldControl(Enterprise enterprise, IReadWrite io)
+        : base("Shield Control", Command.SHE, io)
    {
-        private readonly Enterprise _enterprise;
-        private readonly Output _output;
-        private readonly Input _input;
-
-        internal ShieldControl(Enterprise enterprise, Output output, Input input)
-            : base("Shield Control", Command.SHE, output)
-        {
-            _enterprise = enterprise;
-            _output = output;
-            _input = input;
-        }
-
-        internal float ShieldEnergy { get; set; }
-
-        protected override bool CanExecuteCommand() => IsOperational("{name} inoperable");
-
-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
-        {
-            _output.WriteLine($"Energy available = {_enterprise.TotalEnergy}");
-            var requested = _input.GetNumber($"Number of units to shields");
-
-            if (Validate(requested))
-            {
-                ShieldEnergy = requested;
-                _output.Write(Strings.ShieldsSet, requested);
-            }
-            else
-            {
-                _output.WriteLine("<SHIELDS UNCHANGED>");
-            }
-
-            return CommandResult.Ok;
-        }
-
-        private bool Validate(float requested)
-        {
-            if (requested > _enterprise.TotalEnergy)
-            {
-                _output.WriteLine("Shield Control reports, 'This is not the Federation Treasury.'");
-                return false;
-            }
-
-            return requested >= 0 && requested != ShieldEnergy;
-        }
-
-        internal void AbsorbHit(int hitStrength) => ShieldEnergy -= hitStrength;
-
-        internal void DropShields() => ShieldEnergy = 0;
+        _enterprise = enterprise;
+        _io = io;
    }
+
+    internal float ShieldEnergy { get; set; }
+
+    protected override bool CanExecuteCommand() => IsOperational("{name} inoperable");
+
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        _io.WriteLine($"Energy available = {_enterprise.TotalEnergy}");
+        var requested = _io.ReadNumber($"Number of units to shields");
+
+        if (Validate(requested))
+        {
+            ShieldEnergy = requested;
+            _io.Write(Strings.ShieldsSet, requested);
+        }
+        else
+        {
+            _io.WriteLine("<SHIELDS UNCHANGED>");
+        }
+
+        return CommandResult.Ok;
+    }
+
+    private bool Validate(float requested)
+    {
+        if (requested > _enterprise.TotalEnergy)
+        {
+            _io.WriteLine("Shield Control reports, 'This is not the Federation Treasury.'");
+            return false;
+        }
+
+        return requested >= 0 && requested != ShieldEnergy;
+    }
+
+    internal void AbsorbHit(int hitStrength) => ShieldEnergy -= hitStrength;
+
+    internal void DropShields() => ShieldEnergy = 0;
 }
--- a/84_Super_Star_Trek/csharp/Systems/ShortRangeSensors.cs
+++ b/84_Super_Star_Trek/csharp/Systems/ShortRangeSensors.cs
@@ -2,61 +2,61 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal class ShortRangeSensors : Subsystem
 {
-    internal class ShortRangeSensors : Subsystem
+    private readonly Enterprise _enterprise;
+    private readonly Galaxy _galaxy;
+    private readonly Game _game;
+    private readonly IReadWrite _io;
+
+    internal ShortRangeSensors(Enterprise enterprise, Galaxy galaxy, Game game, IReadWrite io)
+        : base("Short Range Sensors", Command.SRS, io)
    {
-        private readonly Enterprise _enterprise;
-        private readonly Galaxy _galaxy;
-        private readonly Game _game;
-        private readonly Output _output;
+        _enterprise = enterprise;
+        _galaxy = galaxy;
+        _game = game;
+        _io = io;
+    }

-        internal ShortRangeSensors(Enterprise enterprise, Galaxy galaxy, Game game, Output output)
-            : base("Short Range Sensors", Command.SRS, output)
+    protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+    {
+        if (_enterprise.IsDocked)
        {
-            _enterprise = enterprise;
-            _galaxy = galaxy;
-            _game = game;
-            _output = output;
+            _io.WriteLine(Strings.ShieldsDropped);
        }

-        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
+        if (Condition < 0)
        {
-            if (_enterprise.IsDocked)
-            {
-                _output.WriteLine(Strings.ShieldsDropped);
-            }
-
-            if (Condition < 0)
-            {
-                _output.WriteLine(Strings.ShortRangeSensorsOut);
-            }
-
-            _output.WriteLine("---------------------------------");
-            quadrant.GetDisplayLines()
-                .Zip(GetStatusLines(), (sectors, status) => $" {sectors}         {status}")
-                .ToList()
-                .ForEach(l => _output.WriteLine(l));
-            _output.WriteLine("---------------------------------");
-
-            return CommandResult.Ok;
+            _io.WriteLine(Strings.ShortRangeSensorsOut);
        }

-        internal IEnumerable<string> GetStatusLines()
-        {
-            yield return $"Stardate           {_game.Stardate}";
-            yield return $"Condition          {_enterprise.Condition}";
-            yield return $"Quadrant           {_enterprise.QuadrantCoordinates}";
-            yield return $"Sector             {_enterprise.SectorCoordinates}";
-            yield return $"Photon torpedoes   {_enterprise.PhotonTubes.TorpedoCount}";
-            yield return $"Total energy       {Math.Ceiling(_enterprise.TotalEnergy)}";
-            yield return $"Shields            {(int)_enterprise.ShieldControl.ShieldEnergy}";
-            yield return $"Klingons remaining {_galaxy.KlingonCount}";
-        }
+        _io.WriteLine("---------------------------------");
+        quadrant.GetDisplayLines()
+            .Zip(GetStatusLines(), (sectors, status) => $" {sectors}         {status}")
+            .ToList()
+            .ForEach(l => _io.WriteLine(l));
+        _io.WriteLine("---------------------------------");
+
+        return CommandResult.Ok;
+    }
+
+    internal IEnumerable<string> GetStatusLines()
+    {
+        yield return $"Stardate           {_game.Stardate}";
+        yield return $"Condition          {_enterprise.Condition}";
+        yield return $"Quadrant           {_enterprise.QuadrantCoordinates}";
+        yield return $"Sector             {_enterprise.SectorCoordinates}";
+        yield return $"Photon torpedoes   {_enterprise.PhotonTubes.TorpedoCount}";
+        yield return $"Total energy       {Math.Ceiling(_enterprise.TotalEnergy)}";
+        yield return $"Shields            {(int)_enterprise.ShieldControl.ShieldEnergy}";
+        yield return $"Klingons remaining {_galaxy.KlingonCount}";
    }
 }
--- a/84_Super_Star_Trek/csharp/Systems/Subsystem.cs
+++ b/84_Super_Star_Trek/csharp/Systems/Subsystem.cs
@@ -1,68 +1,68 @@
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Space;

-namespace SuperStarTrek.Systems
+namespace SuperStarTrek.Systems;
+
+internal abstract class Subsystem
 {
-    internal abstract class Subsystem
+    private readonly IReadWrite _io;
+
+    protected Subsystem(string name, Command command, IReadWrite io)
    {
-        private readonly Output _output;
-
-        protected Subsystem(string name, Command command, Output output)
-        {
-            Name = name;
-            Command = command;
-            Condition = 0;
-            _output = output;
-        }
-
-        internal string Name { get; }
-
-        internal float Condition { get; private set; }
-
-        internal bool IsDamaged => Condition < 0;
-
-        internal Command Command { get; }
-
-        protected virtual bool CanExecuteCommand() => true;
-
-        protected bool IsOperational(string notOperationalMessage)
-        {
-            if (IsDamaged)
-            {
-                _output.WriteLine(notOperationalMessage.Replace("{name}", Name));
-                return false;
-            }
-
-            return true;
-        }
-
-        internal CommandResult ExecuteCommand(Quadrant quadrant)
-            => CanExecuteCommand() ? ExecuteCommandCore(quadrant) : CommandResult.Ok;
-
-        protected abstract CommandResult ExecuteCommandCore(Quadrant quadrant);
-
-        internal virtual void Repair()
-        {
-            if (IsDamaged)
-            {
-                Condition = 0;
-            }
-        }
-
-        internal virtual bool Repair(float repairWorkDone)
-        {
-            if (IsDamaged)
-            {
-                Condition += repairWorkDone;
-                if (Condition > -0.1f && Condition < 0)
-                {
-                    Condition = -0.1f;
-                }
-            }
-
-            return !IsDamaged;
-        }
-
-        internal void TakeDamage(float damage) => Condition -= damage;
+        Name = name;
+        Command = command;
+        Condition = 0;
+        _io = io;
    }
+
+    internal string Name { get; }
+
+    internal float Condition { get; private set; }
+
+    internal bool IsDamaged => Condition < 0;
+
+    internal Command Command { get; }
+
+    protected virtual bool CanExecuteCommand() => true;
+
+    protected bool IsOperational(string notOperationalMessage)
+    {
+        if (IsDamaged)
+        {
+            _io.WriteLine(notOperationalMessage.Replace("{name}", Name));
+            return false;
+        }
+
+        return true;
+    }
+
+    internal CommandResult ExecuteCommand(Quadrant quadrant)
+        => CanExecuteCommand() ? ExecuteCommandCore(quadrant) : CommandResult.Ok;
+
+    protected abstract CommandResult ExecuteCommandCore(Quadrant quadrant);
+
+    internal virtual void Repair()
+    {
+        if (IsDamaged)
+        {
+            Condition = 0;
+        }
+    }
+
+    internal virtual bool Repair(float repairWorkDone)
+    {
+        if (IsDamaged)
+        {
+            Condition += repairWorkDone;
+            if (Condition > -0.1f && Condition < 0)
+            {
+                Condition = -0.1f;
+            }
+        }
+
+        return !IsDamaged;
+    }
+
+    internal void TakeDamage(float damage) => Condition -= damage;
 }
--- a/84_Super_Star_Trek/csharp/Systems/WarpEngines.cs
+++ b/84_Super_Star_Trek/csharp/Systems/WarpEngines.cs
@@ -1,4 +1,5 @@
 using System;
+using Games.Common.IO;
 using SuperStarTrek.Commands;
 using SuperStarTrek.Objects;
 using SuperStarTrek.Resources;
@@ -9,20 +10,18 @@ namespace SuperStarTrek.Systems
    internal class WarpEngines : Subsystem
    {
        private readonly Enterprise _enterprise;
-        private readonly Output _output;
-        private readonly Input _input;
+        private readonly IReadWrite _io;

-        internal WarpEngines(Enterprise enterprise, Output output, Input input)
-            : base("Warp Engines", Command.NAV, output)
+        internal WarpEngines(Enterprise enterprise, IReadWrite io)
+            : base("Warp Engines", Command.NAV, io)
        {
            _enterprise = enterprise;
-            _output = output;
-            _input = input;
+            _io = io;
        }

        protected override CommandResult ExecuteCommandCore(Quadrant quadrant)
        {
-            if (_input.TryGetCourse("Course", "   Lt. Sulu", out var course) &&
+            if (_io.TryReadCourse("Course", "   Lt. Sulu", out var course) &&
                TryGetWarpFactor(out var warpFactor) &&
                TryGetDistanceToMove(warpFactor, out var distanceToMove))
            {
@@ -51,12 +50,12 @@ namespace SuperStarTrek.Systems
        private bool TryGetWarpFactor(out float warpFactor)
        {
            var maximumWarp = IsDamaged ? 0.2f : 8;
-            if (_input.TryGetNumber("Warp Factor", 0, maximumWarp, out warpFactor))
+            if (_io.TryReadNumberInRange("Warp Factor", 0, maximumWarp, out warpFactor))
            {
                return warpFactor > 0;
            }

-            _output.WriteLine(
+            _io.WriteLine(
                IsDamaged && warpFactor > maximumWarp
                    ? "Warp engines are damaged.  Maximum speed = warp 0.2"
                    : $"  Chief Engineer Scott reports, 'The engines won't take warp {warpFactor} !'");
@@ -69,14 +68,14 @@ namespace SuperStarTrek.Systems
            distanceToTravel = (int)Math.Round(warpFactor * 8, MidpointRounding.AwayFromZero);
            if (distanceToTravel <= _enterprise.Energy) { return true; }

-            _output.WriteLine("Engineering reports, 'Insufficient energy available")
-                .WriteLine($"                      for maneuvering at warp {warpFactor} !'");
+            _io.WriteLine("Engineering reports, 'Insufficient energy available");
+            _io.WriteLine($"                      for maneuvering at warp {warpFactor} !'");

            if (distanceToTravel <= _enterprise.TotalEnergy && !_enterprise.ShieldControl.IsDamaged)
            {
-                _output.Write($"Deflector control room acknowledges {_enterprise.ShieldControl.ShieldEnergy} ")
-                    .WriteLine("units of energy")
-                    .WriteLine("                         presently deployed to shields.");
+                _io.Write($"Deflector control room acknowledges {_enterprise.ShieldControl.ShieldEnergy} ");
+                _io.WriteLine("units of energy");
+                _io.WriteLine("                         presently deployed to shields.");
            }

            return false;