Initial commit

6 files changed, 929 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..58343ae
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+bin/
+obj/
+/packages/
+riderModule.iml
+/_ReSharper.Caches/
+/.idea
diff --git a/Program.cs b/Program.cs
new file mode 100644
index 0000000..800ee12
--- /dev/null
+++ b/Program.cs
@@ -0,0 +1,195 @@
+namespace pgch8;
+
+using System.Text;
+using Npgsql;
+
+class Program
+{
+    private static NpgsqlConnection _conn;
+    private static Screen _screen;
+    
+    static void Main(string[] args)
+    {
+        CreateConnection();
+        Program.Reset();
+
+        CreateScreen();
+        WriteRom("/Users/melodidey/Source/csharp/pgch8/test_opcode.ch8");
+        WriteFont([
+            0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
+            0x20, 0x60, 0x20, 0x20, 0x70, // 1
+            0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
+            0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
+            0x90, 0x90, 0xF0, 0x10, 0x10, // 4
+            0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
+            0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
+            0xF0, 0x10, 0x20, 0x40, 0x40, // 7
+            0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
+            0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
+            0xF0, 0x90, 0xF0, 0x90, 0x90, // A
+            0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
+            0xF0, 0x80, 0x80, 0x80, 0xF0, // C
+            0xE0, 0x90, 0x90, 0x90, 0xE0, // D
+            0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
+            0xF0, 0x80, 0xF0, 0x80, 0x80  // F
+        ]);
+
+        while (true)
+        {
+            Program.Clock();
+            if (Program.IsScreenDirty())
+            {
+                _screen.Pixels = Program.GetScreenPixels();
+                _screen.Render();
+                Program.MarkScreenClean();
+            }
+            
+            Thread.Sleep(1000 / 60);
+        }
+    }
+    
+    private static void Reset()
+    {
+        Program.Execute("select private.reset();");
+    }
+    
+    private static void Clock()
+    {
+        Program.Execute("select private.clock();");
+    }
+    
+    private static bool IsScreenDirty()
+    {
+        return Program.QuerySingle<bool>("select private.is_screen_dirty();");
+    }
+    
+    private static void MarkScreenClean()
+    {
+        Program.Execute("select private.mark_screen_clean();");
+    }
+    
+    private static bool[] GetScreenPixels()
+    {
+        return Program.Query(
+            "select value from private.display order by i;",
+            reader =>
+            {
+                List<bool> pixels = new();
+                while (reader.Read())
+                {
+                    pixels.Add(reader.GetBoolean(0));
+                }
+                return pixels.ToArray();
+            });
+    }
+
+    private static void CreateConnection()
+    {
+        Program._conn = new("Host=localhost;Username=melodidey;Database=emulator");
+        Program._conn.Open();
+    }
+
+    private static void CreateScreen()
+    {
+        int screenWidth = QuerySingle<int>("select value from private.constants where label = 'Screen Width';");
+        int screenHeight = QuerySingle<int>("select value from private.constants where label = 'Screen Height';");
+        
+        Program._screen = new Screen(screenWidth, screenHeight);
+    }
+    
+    private static void WriteRom(string path)
+    {
+        byte[] rom = File.ReadAllBytes(path);
+
+        int romStart = QuerySingle<int>(
+            "select value_word from private.constants where label = 'Program Start';"
+        );
+
+        for (int i = 0; i < rom.Length; i++)
+        {
+            Execute(
+                "update private.memory set value = @p1 where address = @p0;",
+                romStart + i,
+                rom[i]
+            );
+        }
+    }
+
+    private static void WriteFont(byte[] font)
+    {
+        int fontStart = QuerySingle<int>(
+            "select value_word from private.constants where label = 'Font Start';"
+        );
+
+        for (int i = 0; i < font.Length; i++)
+        {
+            Execute(
+                "update private.memory set value = @p1 where address = @p0;",
+                fontStart + i,
+                font[i]
+            );
+        }
+    }
+
+    static void Execute(string query, params object[] parameters)
+    {
+        using var cmd = new NpgsqlCommand(query, Program._conn);
+        for (int i = 0; i < parameters.Length; i++)
+        {
+            cmd.Parameters.AddWithValue($"@p{i}", parameters[i]);
+        }
+        cmd.ExecuteNonQuery();
+    }
+    
+    static T Query<T>(string query, Func<NpgsqlDataReader, T> map)
+    {
+        using var cmd = new NpgsqlCommand(query, Program._conn);
+        using var reader = cmd.ExecuteReader();
+        return map(reader);
+    }
+    
+    static T QuerySingle<T>(string query)
+    {
+        try
+        {
+            return Query(query, reader =>
+            {
+                reader.Read();
+                return reader.GetFieldValue<T>(0);
+            }); 
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error executing query '{query}': {ex.Message}");
+            throw;
+        }
+    }
+}
+
+class Screen
+{
+    public int Width { get; set; }
+    public int Height { get; set; }
+    public bool[] Pixels { get; set; }
+    
+    public Screen(int width, int height)
+    {
+        Width = width;
+        Height = height;
+        Pixels = new bool[width * height];
+    }
+
+    public void Render()
+    {
+        StringBuilder sb = new();
+        for (int i = 0; i < Pixels.Length; i++)
+        {
+            sb.Append(Pixels[i] ? "#" : " ");
+            if ((i + 1) % Width == 0)
+                sb.AppendLine();
+        }
+        
+        Console.Clear();
+        Console.WriteLine(sb.ToString());
+    }
+}
\ No newline at end of file
diff --git a/emulator.sql b/emulator.sql
new file mode 100644
index 0000000..10bb18a
--- /dev/null
+++ b/emulator.sql
@@ -0,0 +1,698 @@
+drop schema if exists private cascade;
+
+create schema private;
+
+create table private.constants
+(
+    id         integer primary key,
+    label      varchar(20) not null,
+    value      integer,
+    value_word integer
+);
+
+create index idx_constants_label on private.constants (label);
+
+create table private.registers
+(
+    id    integer primary key,
+    value integer not null
+);
+
+create table private.state
+(
+    id         integer primary key,
+    label      varchar(20) not null,
+    value      integer,
+    value_word integer
+);
+
+create table private.timers
+(
+    id    integer primary key,
+    label varchar(20) not null,
+    value integer     not null
+);
+
+create table private.inputs
+(
+    id    integer primary key,
+    value integer not null
+);
+
+create table private.memory
+(
+    address integer primary key,
+    value   integer not null
+);
+
+create table private.display
+(
+    i     integer primary key,
+    value boolean
+);
+
+create table private.stack
+(
+    id    integer primary key,
+    value integer not null
+);
+
+-- contains the current opcode and its parts for easy access
+-- parts are: opcode, k, x, y, n, nn, nnn
+create or replace view private.opcode_parts as
+select s.value_word               as opcode,
+       s.value_word & 61440 >> 12 as k,
+       (s.value_word & 3840) >> 8 as x,
+       (s.value_word & 240) >> 4  as y,
+       s.value_word & 15          as n,
+       s.value_word & 255         as nn,
+       s.value_word & 4095        as nnn
+from private.state s
+where s.id = 4;
+
+create or replace function private.reset()
+    returns void as
+$$
+begin
+    truncate table private.constants;
+    insert into private.constants (id, label, value, value_word)
+    values (1, 'Font Start', null, 61440),
+           (2, 'Program Start', null, 512),
+           (3, 'Screen Width', 64, null),
+           (4, 'Screen Height', 32, null),
+           (5, 'Register Count', 16, null),
+           (6, 'Stack Depth', 16, null),
+           (7, 'Input Count', 16, null);
+
+
+    truncate table private.state;
+    insert into private.state (id, label, value, value_word)
+    values (1, 'Program Counter', null, (select value_word from private.constants where label = 'Program Start')),
+           (2, 'Index Register', null, 0),
+           (3, 'Stack Pointer', 0, null),
+           (4, 'Opcode', null, 0),
+           (5, 'Screen Dirty', 0, null);
+
+
+    truncate table private.registers;
+    insert into private.registers (id, value)
+    select gs, 0
+    from generate_series(0,
+                         (select value from private.constants where label = 'Register Count') - 1) as gs;
+
+
+    truncate table private.memory;
+    insert into private.memory (address, value)
+    select gs, 0
+    from generate_series(0, 4095) as gs;
+
+
+    truncate table private.display;
+    insert into private.display (i, value)
+    select gs, false
+    from generate_series(0,
+                         (select value from private.constants where label = 'Screen Width') *
+                         (select value from private.constants where label = 'Screen Height') - 1) as gs;
+
+
+    truncate table private.timers;
+    insert into private.timers (id, label, value)
+    values (1, 'Delay Timer', 0),
+           (2, 'Sound Timer', 0);
+
+
+    truncate table private.stack;
+    insert into private.stack (id, value)
+    select gs, 0
+    from generate_series(0,
+                         (select value from private.constants where label = 'Stack Depth') - 1) as gs;
+
+
+    truncate table private.inputs;
+    insert into private.inputs (id, value)
+    select gs, 0
+    from generate_series(0,
+                         (select value from private.constants where label = 'Input Count') - 1) as gs;
+end;
+$$ language plpgsql;
+
+
+create or replace function private.read_register(register_id integer)
+    returns integer as
+$$
+declare
+    reg_value integer;
+begin
+    select value
+    into reg_value
+    from private.registers
+    where id = register_id;
+    return reg_value;
+end;
+$$ language plpgsql;
+
+create or replace function private.write_register(register_id integer, new_value integer)
+    returns void as
+$$
+begin
+    update private.registers
+    set value = new_value
+    where id = register_id;
+end;
+$$ language plpgsql;
+
+create or replace function private.push_stack(new_value integer)
+    returns void as
+$$
+begin
+    -- stack[SP] = new_value
+    update private.stack
+    set value = new_value
+    where id = (select value from private.state where id = 3);
+
+    -- SP++
+    update private.state
+    set value = value + 1
+    where id = 3;
+end;
+$$ language plpgsql;
+
+create or replace function private.pop_stack()
+    returns integer as
+$$
+declare
+    stack_value integer;
+begin
+    -- SP--
+    update private.state
+    set value = value - 1
+    where id = 3;
+
+    -- return stack[SP]
+    select value
+    into stack_value
+    from private.stack
+    where id = (select value from private.state where id = 3);
+    return stack_value;
+end;
+$$ language plpgsql;
+
+create or replace function private.read_memory(read_address integer)
+    returns integer as
+$$
+declare
+    mem_value integer;
+begin
+    select value
+    into mem_value
+    from private.memory
+    where address = read_address;
+    return mem_value;
+end;
+$$ language plpgsql;
+
+create or replace function private.write_memory(write_address integer, new_value integer)
+    returns void as
+$$
+begin
+    update private.memory
+    set value = new_value
+    where address = write_address;
+end;
+$$ language plpgsql;
+
+create or replace function private.fetch()
+    returns void as
+$$
+begin
+    -- fetch the opcode at the current program counter
+    update private.state
+    set value_word =
+            ((select value from private.memory where address = (select value_word from private.state where id = 1)) << 8)
+                |
+            (select value from private.memory where address = (select value_word from private.state where id = 1) + 1)
+    where id = 4;
+end;
+$$ language plpgsql;
+
+create or replace function private.increment_program_counter()
+    returns void as
+$$
+begin
+    update private.state
+    set value_word = value_word + 2
+    where id = 1;
+end;
+$$ language plpgsql;
+
+-- section for opcode execution functions
+
+-- JUMP
+create or replace function private.exec_1nnn(op private.opcode_parts)
+    returns void as
+$$
+begin
+    update private.state
+    set value_word = op.nnn
+    where id = 1; -- Program Counter
+end;
+$$ language plpgsql;
+
+-- CALL
+create or replace function private.exec_2nnn(op private.opcode_parts)
+    returns void as
+$$
+declare
+    current_pc integer;
+begin
+    select value_word
+    into current_pc
+    from private.state
+    where id = 1;
+
+    perform private.push_stack(current_pc);
+
+    update private.state
+    set value_word = op.nnn
+    where id = 1;
+end;
+$$ language plpgsql;
+
+
+-- RETURN
+create or replace function private.exec_group_0(op private.opcode_parts)
+    returns void as
+$$
+begin
+    if op.opcode = 238 then -- 0x00EE = 238 decimal
+        update private.state
+        set value_word = private.pop_stack()
+        where id = 1;
+    elsif op.opcode = 224 then -- 0x00E0 = 224 decimal
+        update private.display
+        set value = false;
+    else
+        raise exception 'Unknown 0-group opcode %', op.opcode;
+    end if;
+end;
+$$ language plpgsql;
+
+-- SET REGISTER
+create or replace function private.exec_6xnn(op private.opcode_parts)
+    returns void as
+$$
+begin
+    update private.registers
+    set value = op.nn
+    where id = op.x;
+end;
+$$ language plpgsql;
+
+-- ADD TO REGISTER
+create or replace function private.exec_7xnn(op private.opcode_parts)
+    returns void as
+$$
+begin
+    update private.registers
+    set value = (value + op.nn) % 256
+    where id = op.x;
+end;
+$$ language plpgsql;
+
+-- SKIP IF EQUAL
+create or replace function private.exec_3xnn(op private.opcode_parts)
+    returns void as
+$$
+declare
+    vx integer;
+begin
+    select value
+    into vx
+    from private.registers
+    where id = op.x;
+
+    if vx = op.nn then
+        update private.state
+        set value_word = value_word + 2
+        where id = 1;
+    end if;
+end;
+$$ language plpgsql;
+
+-- SKIP IF NOT EQUAL
+create or replace function private.exec_4xnn(op private.opcode_parts)
+    returns void as
+$$
+declare
+    vx integer;
+begin
+    select value
+    into vx
+    from private.registers
+    where id = op.x;
+
+    if vx != op.nn then
+        update private.state
+        set value_word = value_word + 2
+        where id = 1;
+    end if;
+end;
+$$ language plpgsql;
+
+-- SKIP IF REGISTERS EQUAL
+create or replace function private.exec_5xy0(op private.opcode_parts)
+    returns void as
+$$
+declare
+    vx integer;
+    vy integer;
+begin
+    select value into vx from private.registers where id = op.x;
+    select value into vy from private.registers where id = op.y;
+
+    if vx = vy then
+        update private.state
+        set value_word = value_word + 2
+        where id = 1;
+    end if;
+end;
+$$ language plpgsql;
+
+-- SKIP IF REGISTERS NOT EQUAL
+create or replace function private.exec_9xy0(op record)
+    returns void as
+$$
+declare
+    vx integer;
+    vy integer;
+begin
+    select value into vx from private.registers where id = op.x;
+    select value into vy from private.registers where id = op.y;
+
+    if vx <> vy then
+        update private.state set value_word = value_word + 2 where id = 1;
+    end if;
+end;
+$$ language plpgsql;
+
+-- ARITHMETIC AND BITWISE OPERATIONS
+create or replace function private.exec_group_8(op record)
+    returns void as
+$$
+declare
+    vx     integer;
+    vy     integer;
+    result integer;
+begin
+    select value into vx from private.registers where id = op.x;
+    select value into vy from private.registers where id = op.y;
+
+    case op.n
+        when 0 then update private.registers set value = vy where id = op.x;
+        when 1 then update private.registers set value = (vx | vy) where id = op.x;
+        when 2 then update private.registers set value = (vx & vy) where id = op.x;
+        when 3 then update private.registers set value = (vx # vy) where id = op.x;
+        when 4 then
+            result := vx + vy;
+            update private.registers set value = result % 256 where id = op.x;
+            update private.registers set value = (result > 255)::int where id = 15;
+        when 5 then
+            update private.registers set value = (vx - vy + 256) % 256 where id = op.x;
+            update private.registers set value = (vx >= vy)::int where id = 15;
+        when 6 then
+            update private.registers set value = vx >> 1 where id = op.x;
+            update private.registers set value = (vx & 1) where id = 15;
+        when 7 then
+            update private.registers set value = (vy - vx + 256) % 256 where id = op.x;
+            update private.registers set value = (vy >= vx)::int where id = 15;
+        when 14 then
+            update private.registers set value = (vx << 1) % 256 where id = op.x;
+            update private.registers set value = ((vx & 128) >> 7) where id = 15;
+        else raise exception 'Unknown 8xy? opcode %', op.opcode;
+        end case;
+end;
+$$ language plpgsql;
+
+-- SET INDEX REGISTER
+create or replace function private.exec_annn(op record)
+    returns void as
+$$
+begin
+    update private.state set value_word = op.nnn where id = 2;
+end;
+$$ language plpgsql;
+
+-- JUMP WITH OFFSET
+create or replace function private.exec_bnnn(op record)
+    returns void as
+$$
+declare
+    v0 integer;
+begin
+    select value into v0 from private.registers where id = 0;
+
+    update private.state
+    set value_word = op.nnn + v0
+    where id = 1;
+end;
+$$ language plpgsql;
+
+-- RANDOM NUMBER
+create or replace function private.exec_cxnn(op record)
+    returns void as
+$$
+declare
+    rnd integer;
+begin
+    rnd := floor(random() * 256);
+    update private.registers
+    set value = (rnd & op.nn)
+    where id = op.x;
+end;
+$$ language plpgsql;
+
+-- INPUT
+create or replace function private.exec_group_e(op record)
+    returns void as
+$$
+declare
+    vx      integer;
+    pressed integer;
+begin
+    select value into vx from private.registers where id = op.x;
+    select value into pressed from private.inputs where id = vx;
+
+    if op.nn = 158 then -- 9E
+        if pressed = 1 then
+            update private.state set value_word = value_word + 2 where id = 1;
+        end if;
+
+    elsif op.nn = 161 then -- A1
+        if pressed = 0 then
+            update private.state set value_word = value_word + 2 where id = 1;
+        end if;
+
+    else
+        raise exception 'Unknown Ex?? opcode %', op.opcode;
+    end if;
+end;
+$$ language plpgsql;
+
+-- FGROUP
+create or replace function private.exec_group_f(op record)
+    returns void as
+$$
+declare
+    vx integer;
+    i  integer;
+begin
+    select value into vx from private.registers where id = op.x;
+    select value_word into i from private.state where id = 2;
+
+    case op.nn
+
+        when 7 then -- Fx07
+        update private.registers
+        set value = (select value from private.timers where label = 'Delay Timer')
+        where id = op.x;
+
+        when 15 then -- Fx15
+        update private.timers set value = vx where label = 'Delay Timer';
+
+        when 18 then -- Fx18
+        update private.timers set value = vx where label = 'Sound Timer';
+
+        when 30 then -- Fx1E
+        update private.state set value_word = i + vx where id = 2;
+
+        when 41 then -- Fx29
+        update private.state set value_word = vx * 5 where id = 2;
+
+        when 51 then -- Fx33 (BCD)
+        update private.memory set value = vx / 100 where address = i;
+        update private.memory set value = (vx / 10) % 10 where address = i + 1;
+        update private.memory set value = vx % 10 where address = i + 2;
+
+        when 85 then -- Fx55
+        for i in 0..op.x
+            loop
+                update private.memory
+                set value = (select value from private.registers where id = i)
+                where address = i + i;
+            end loop;
+
+        when 101 then -- Fx65
+        for i in 0..op.x
+            loop
+                update private.registers
+                set value = (select value from private.memory where address = i + i)
+                where id = i;
+            end loop;
+
+        else raise exception 'Unknown Fx?? opcode %', op.opcode;
+        end case;
+end;
+$$ language plpgsql;
+
+create or replace function private.exec_dxyn(op record)
+    returns void as
+$$
+declare
+    vx          integer;
+    vy          integer;
+    i_reg           integer;
+    sprite_row  integer;
+    sprite_byte integer;
+    x_pos       integer;
+    y_pos       integer;
+    pixel_idx   integer;
+    old_pixel   boolean;
+    collision   integer := 0;
+    row         integer;
+    col         integer;
+begin
+    -- fetch registers and I
+    select value into vx from private.registers where id = op.x;
+    select value into vy from private.registers where id = op.y;
+    select value_word into i_reg from private.state where id = 2;
+
+    -- clear VF
+    update private.registers set value = 0 where id = 15;
+
+    -- for each row of sprite
+    for row in 0..op.n - 1
+        loop
+            -- read byte from memory
+            select value into sprite_byte from private.memory where address = i_reg + row;
+
+            -- draw each bit
+            for col in 0..7
+                loop
+                    -- only process if bit is 1
+                    if ((sprite_byte >> (7 - col)) & 1) = 1 then
+                        -- calculate pixel coordinates (wrap)
+                        x_pos := (vx + col) % 64;
+                        y_pos := (vy + row) % 32;
+
+                        pixel_idx := y_pos * 64 + x_pos;
+
+                        -- get old pixel
+                        select value into old_pixel from private.display where private.display.i = pixel_idx;
+
+                        -- check collision
+                        if old_pixel then
+                            collision := 1;
+                        end if;
+
+                        -- XOR pixel
+                        update private.display
+                        set value = not old_pixel
+                        where private.display.i = pixel_idx;
+                    end if;
+                end loop;
+        end loop;
+
+    -- set VF if any collision
+    if collision = 1 then
+        update private.registers set value = 1 where id = 15;
+    end if;
+
+    -- mark screen dirty
+    update private.state
+    set value = 1
+    where id = 5;
+end;
+$$ language plpgsql;
+
+-- exit section
+
+create or replace function private.mark_screen_clean()
+    returns void as
+$$
+begin
+    update private.state
+    set value = 0
+    where id = 5;
+end;
+$$ language plpgsql;
+
+create or replace function private.is_screen_dirty()
+    returns boolean as
+$$
+declare
+    dirty boolean;
+begin
+    select value::boolean
+    into dirty
+    from private.state
+    where id = 5;
+    return dirty;
+end;
+$$ language plpgsql;
+
+create or replace function private.clock()
+    returns void as
+$$
+declare
+    op private.opcode_parts;
+begin
+    -- fetch
+    perform private.fetch();
+    perform private.increment_program_counter();
+
+    -- opcode dispatch
+    select *
+    into op
+    from private.opcode_parts;
+
+    case op.k
+        when 0 then perform private.exec_group_0(op);
+        when 1 then perform private.exec_1nnn(op);
+        when 2 then perform private.exec_2nnn(op);
+        when 3 then perform private.exec_3xnn(op);
+        when 4 then perform private.exec_4xnn(op);
+        when 5 then perform private.exec_5xy0(op);
+        when 6 then perform private.exec_6xnn(op);
+        when 7 then perform private.exec_7xnn(op);
+        when 8 then perform private.exec_group_8(op);
+        when 9 then perform private.exec_9xy0(op);
+        when 10 then perform private.exec_annn(op);
+        when 11 then perform private.exec_bnnn(op);
+        when 12 then perform private.exec_cxnn(op);
+        when 13 then perform private.exec_dxyn(op);
+        when 14 then perform private.exec_group_e(op);
+        when 15 then perform private.exec_group_f(op);
+        else raise exception 'Unknown opcode %', op.opcode;
+        end case;
+
+    -- decrement timers if they are above 0
+    update private.timers
+    set value = value - 1
+    where value > 0;
+end;
+$$ language plpgsql;
+
+
+select private.reset();
+
+--select private.clock();
\ No newline at end of file
diff --git a/pgch8.csproj b/pgch8.csproj
new file mode 100644
index 0000000..c0140e4
--- /dev/null
+++ b/pgch8.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net9.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Npgsql" Version="10.0.1" />
+    </ItemGroup>
+
+</Project>
diff --git a/pgch8.sln b/pgch8.sln
new file mode 100644
index 0000000..a3b4880
--- /dev/null
+++ b/pgch8.sln
@@ -0,0 +1,16 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "pgch8", "pgch8.csproj", "{A7F7E4C2-2B28-45DC-B503-A395676FA4A3}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{A7F7E4C2-2B28-45DC-B503-A395676FA4A3}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A7F7E4C2-2B28-45DC-B503-A395676FA4A3}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A7F7E4C2-2B28-45DC-B503-A395676FA4A3}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A7F7E4C2-2B28-45DC-B503-A395676FA4A3}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
diff --git a/test_opcode.ch8 b/test_opcode.ch8
new file mode 100644
index 0000000..f540f69
--- /dev/null
+++ b/test_opcode.ch8