320 lines
10 KiB
C#
320 lines
10 KiB
C#
using BizHawk.Common;
|
|
using BizHawk.Common.NumberExtensions;
|
|
|
|
namespace BizHawk.Emulation.Cores.Atari.Atari2600
|
|
{
|
|
/*
|
|
* Spectravideo Compumate Add-on Kevtris Documentation
|
|
|
|
This is more than just a cartridge mapper- it's also a "computer" add-on.
|
|
There's two 8K EPROMs soldered on top of each other. There's two short
|
|
wires with DB-9's on them which you plug into the two controller ports.
|
|
A 42 or so key membrane keyboard with audio in and audio out, and 1K of RAM.
|
|
|
|
Port A on the RIOT is used to run most of the functions on the Compumate:
|
|
|
|
7 0
|
|
---------
|
|
ACRE 31BB
|
|
|
|
A - Audio input from tape player
|
|
C - Audio out to tape player and 4017 CLK
|
|
R - 4017 RST, and RAM direction. (high = write, low = read)
|
|
E - RAM enable. 1 = disable RAM, 0 = enable RAM
|
|
3 - Row 3 of keyboard
|
|
1 - Row 1 of keyboard
|
|
B - 2 bit ROM bank number
|
|
|
|
All bits are outputs except for the 2 row inputs from the keyboard.
|
|
|
|
Unlike most things, the Compumate uses all three of the TIA inputs on each
|
|
joystick port (paddles and fire).
|
|
|
|
TIA inputs:
|
|
|
|
0 - function key
|
|
1 - pulled high thru 20K resistor
|
|
2 - pulled high thru 20K resistor
|
|
3 - shift key
|
|
4 - Row 0
|
|
5 - Row 2
|
|
|
|
|
|
Memory Map:
|
|
-----------
|
|
|
|
1000-1FFF : selectable 4K ROM bank (selected by D0, D1 on portA)
|
|
|
|
On powerup, the port is all 1's, so the last bank of ROM is enabled, RAM is
|
|
disabled.
|
|
|
|
when RAM is enabled:
|
|
|
|
1000-17FF : 2K of RAM. It's mapped into 1000-17FF. Unlike most 2600 carts,
|
|
bit 5 of portA controls if the RAM is readable or writable. When it's high,
|
|
the RAM is write only. When it's low, it is read only. There's no separate
|
|
read and write ports.
|
|
|
|
|
|
Keyboard:
|
|
---------
|
|
|
|
The keyboard's composed of a 4017 1 of 10 counter, driving the 10 columns of
|
|
the keyboard. It has 4 rows. The 4 row outputs are buffered by inverters.
|
|
|
|
Bit 5 of portA controls the reset line on the 4017. Pulling it high will reset
|
|
scanning to column 0. Pulling it low will allow the counter to be clocked.
|
|
|
|
Bit 6 of portA clocks the 4017. Each rising edge advances the column one
|
|
count.
|
|
|
|
There's 10 columns labelled 0-9, and 4 rows, labelled 0-3.
|
|
|
|
Column
|
|
|
|
0 1 2 3 4 5 6 7 8 9
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| 7 | | 6 | | 8 | | 2 | | 3 | | 0 | | 9 | | 5 | | 1 | | 4 | 0
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| U | | Y | | I | | W | | E | | P | | O | | T | | Q | | R | 1
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ Row
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| J | | H | | K | | S | | D | |ent| | L | | G | | A | | F | 2
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| M | | N | | < | | X | | C | |spc| | > | | B | | Z | | V | 3
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
|
|
Function and Shift are separate keys that are read by 2 of the paddle inputs.
|
|
These two buttons pull the specific paddle input low when pressed.
|
|
|
|
Because the inputs are inverted, a low indicates a pressed button, and a high
|
|
is an unpressed one.
|
|
|
|
The audio input/output are designed to drive a tape player. The audio output is
|
|
buffered through an inverter and 2 resistors and a capacitor to reduce the level
|
|
to feed it into the tape player.
|
|
|
|
The audio input is passed through a .1uf capacitor and is pulled to 1/2 supply
|
|
by two 20K resistors, then it goes through a hex inverting schmitt trigger to
|
|
square it up. This then runs into bit 7 of portA.
|
|
*/
|
|
|
|
/*
|
|
* Spectravideo Compumate Add-on Stella Documentation
|
|
Cartridge class used for SpectraVideo CompuMate bankswitched games.
|
|
|
|
This is more than just a cartridge mapper - it's also a "computer" add-on.
|
|
There's two 8K EPROMs soldered on top of each other. There's two short
|
|
wires with DB-9's on them which you plug into the two controller ports.
|
|
A 42 or so key membrane keyboard with audio in and audio out, and 2K of RAM.
|
|
|
|
There are 4 4K banks selectable at $1000 - $1FFF, and 2K RAM at
|
|
$1800 - $1FFF (R/W 'line' is available at SWCHA D5, so there's no separate
|
|
read and write ports).
|
|
|
|
Bankswitching is done though the controller ports
|
|
SWCHA: D7 = Audio input from tape player
|
|
D6 = Audio out to tape player and 4017 CLK
|
|
1 -> increase key column (0 to 9)
|
|
D5 = 4017 RST, and RAM direction. (high = write, low = read)
|
|
1 -> reset key column to 0 (if D4 = 0)
|
|
0 -> enable RAM writing (if D4 = 1)
|
|
D4 = RAM enable: 1 = disable RAM, 0 = enable RAM
|
|
D3 = keyboard row 3 input (0 = key pressed)
|
|
D2 = keyboard row 1 input (0 = key pressed)
|
|
D1 = bank select high bit
|
|
D0 = bank select low bit
|
|
|
|
INPT0: D7 = FUNC key input (0 on startup / 1 = key pressed)
|
|
INPT1: D7 = always HIGH input (pulled high thru 20K resistor)
|
|
INPT2: D7 = always HIGH input (pulled high thru 20K resistor)
|
|
INPT3: D7 = SHIFT key input (0 on startup / 1 = key pressed)
|
|
INPT4: D7 = keyboard row 0 input (0 = key pressed)
|
|
INPT5: D7 = keyboard row 2 input (0 = key pressed)
|
|
|
|
The keyboard's composed of a 4017 1 of 10 counter, driving the 10 columns of
|
|
the keyboard. It has 4 rows. The 4 row outputs are buffered by inverters.
|
|
|
|
Bit 5 of portA controls the reset line on the 4017. Pulling it high will reset
|
|
scanning to column 0. Pulling it low will allow the counter to be clocked.
|
|
|
|
Bit 6 of portA clocks the 4017. Each rising edge advances the column one
|
|
count.
|
|
|
|
There's 10 columns labelled 0-9, and 4 rows, labelled 0-3.
|
|
|
|
Column
|
|
|
|
0 1 2 3 4 5 6 7 8 9
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| 7 | | 6 | | 8 | | 2 | | 3 | | 0 | | 9 | | 5 | | 1 | | 4 | 0
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| U | | Y | | I | | W | | E | | P | | O | | T | | Q | | R | 1
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ Row
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| J | | H | | K | | S | | D | |ent| | L | | G | | A | | F | 2
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
| M | | N | | < | | X | | C | |spc| | > | | B | | Z | | V | 3
|
|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|
|
|
|
Function and Shift are separate keys that are read by 2 of the paddle inputs.
|
|
These two buttons pull the specific paddle input low when pressed.
|
|
|
|
Because the inputs are inverted, a low indicates a pressed button, and a high
|
|
is an unpressed one.
|
|
|
|
The audio input/output are designed to drive a tape player. The audio output is
|
|
buffered through an inverter and 2 resistors and a capacitor to reduce the level
|
|
to feed it into the tape player.
|
|
|
|
The audio input is passed through a .1uf capacitor and is pulled to 1/2 supply
|
|
by two 20K resistors, then it goes through a hex inverting schmitt trigger to
|
|
square it up. This then runs into bit 7 of portA.
|
|
*/
|
|
internal class mCM : MapperBase
|
|
{
|
|
// TODO: PokeMem
|
|
private ByteBuffer _ram = new ByteBuffer(2048);
|
|
private int _bank4K = 3; // On Start up, controller port is all 1's, so start on the last bank, flags enabled
|
|
private bool _disableRam = true;
|
|
private bool _writeMode = false;
|
|
private int _column = 0;
|
|
|
|
public override void Dispose()
|
|
{
|
|
_ram.Dispose();
|
|
base.Dispose();
|
|
}
|
|
|
|
public override void HardReset()
|
|
{
|
|
_ram = new ByteBuffer(2048);
|
|
_bank4K = 3;
|
|
_disableRam = true;
|
|
_writeMode = true;
|
|
_column = 0;
|
|
|
|
base.HardReset();
|
|
}
|
|
|
|
public override void SyncState(Serializer ser)
|
|
{
|
|
// TODO
|
|
ser.Sync("cartRam", ref _ram);
|
|
ser.Sync("bank4k", ref _bank4K);
|
|
ser.Sync("column", ref _column);
|
|
ser.Sync("disableRam", ref _disableRam);
|
|
ser.Sync("writeMode", ref _writeMode);
|
|
|
|
base.SyncState(ser);
|
|
}
|
|
|
|
public override byte ReadMemory(ushort addr)
|
|
{
|
|
if (addr < 0x1000)
|
|
{
|
|
return base.ReadMemory(addr);
|
|
}
|
|
|
|
// Lower 2K is always the first 2K of the ROM bank
|
|
// Upper 2K is also Rom if ram is enabled
|
|
if (addr < 0x1800 || _disableRam)
|
|
{
|
|
return Core.Rom[(_bank4K << 12) + (addr & 0xFFF)];
|
|
}
|
|
|
|
// 2K of RAM
|
|
if (!_writeMode)
|
|
{
|
|
return _ram[addr & 0x7FF];
|
|
}
|
|
|
|
// Attempting to read while in write mode
|
|
throw new NotTestedException();
|
|
}
|
|
|
|
public override byte PeekMemory(ushort addr)
|
|
{
|
|
return ReadMemory(addr);
|
|
}
|
|
|
|
public override void WriteMemory(ushort addr, byte value)
|
|
{
|
|
//Mimicking the 6532 logic for accesing port A, for testing
|
|
var isPortA = false;
|
|
|
|
if ((addr & 0x0200) == 0) // If the RS bit is not set, this is a ram write
|
|
{
|
|
|
|
}
|
|
else
|
|
{
|
|
// If bit 0x0010 is set, and bit 0x0004 is set, this is a timer write
|
|
if ((addr & 0x0014) == 0x0014)
|
|
{
|
|
|
|
}
|
|
|
|
// If bit 0x0004 is not set, bit 0x0010 is ignored and
|
|
// these are register writes
|
|
else if ((addr & 0x0004) == 0)
|
|
{
|
|
var registerAddr = (ushort)(addr & 0x0007);
|
|
|
|
if (registerAddr == 0x00)
|
|
{
|
|
if (addr != 640)
|
|
{
|
|
// Write Output reg A
|
|
isPortA = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//if (addr == 0x280) //Stella uses only 280
|
|
if (isPortA)
|
|
{
|
|
var bit5 = value.Bit(5);
|
|
var bit4 = value.Bit(4);
|
|
|
|
//D5 RAM direction. (high = write, low = read)
|
|
//0 -> enable RAM writing (if D4 = 1)
|
|
//D4 = RAM enable: 1 = disable RAM, 0 = enable RAM
|
|
_disableRam = bit4;
|
|
//_writeMode = bit5 || bit4; // ?? Am I interpretting this correctly?
|
|
_writeMode = (value & 0x30) == 0x20;
|
|
|
|
_bank4K = value & 0x03;
|
|
|
|
//D6 = 1 -> increase key column (0 to 9)
|
|
//D5 = 1 -> reset key column to 0 (if D4 = 0)
|
|
if (bit5 && !bit4)
|
|
{
|
|
_column = 0;
|
|
}
|
|
|
|
if (value.Bit(6))
|
|
{
|
|
_column = (_column + 1) % 10;
|
|
}
|
|
}
|
|
|
|
if (addr >= 0x1800)
|
|
{
|
|
if (!_disableRam && _writeMode)
|
|
{
|
|
_ram[addr & 0x7FF] = value;
|
|
}
|
|
}
|
|
|
|
base.WriteMemory(addr, value);
|
|
}
|
|
}
|
|
}
|