As I promised , here is a working solution for connecting MSX and PC !
Try this Turbo Pascal code . 4 bits in 4 bits out via Joystick port and Pc
printer port . (Tested and works)
Sincerely Kari Lammassaari/Finland/ACDEMY
Oh shi.. The cable pinout lacks. Post it tomorrow !(I have to measure the
cable)
MSX-side :
-- cut here --
{MSX_PC.INC}
{Connecting MSX via joystick to PC parallel port }
{by Kari Lammassaari (ACADEMY) 1996-98 }
{The routines for PC are in file PC_MSX.PAS }
{REM IMPORTANT !!! In the block send/receive routines the two first
sent/received bytes contain the total lenght of the block including
the two first bytes (low byte first)}
{ This file contain following procedures and functions :
- Procedure JoyByteSend(value:Byte);
- Procedure JoyBlockSend(BuffAddr:Integer);
- Function JoyByteReceive:Byte;
- Procedure JoyBlockReceive(BufAddr:Integer);
and following type definition, which is used also in PC_MSX.PAS
}
Type DataBlockType = Record
Len :Integer;
ChkSum :Integer;
DataId :Byte;
Data :Array[0..255] Of Byte;
End;
Procedure JoyByteSend(value:Byte);
Begin
Inline($f3/
$3a/Value /
$67/$cb/$3c/$cb/$3c/$cb/$3c/$cb/$3c/ {High nibble to H }
$e6/$0f/ $6f/ {Low nibble to L }
$3e/0/$d3/$99/$d9/$d9/$3e/$40/$d3/$99/$d9/$d9/$3a/Value /$d3/$98/
{The code above just writes current byte value on vram addr 0 }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$20/<-6/ { Wait until ready ? }
$3e/$0f/$d3/$a0/ $7d /$f6/$50/ $d3/$a1/ { Send high nibble }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$28/<-6/ {Wait until PC has
received }
$3e/$0f/$d3/$a0/$3e/$40 /$d3/$a1/ {Reset data ready signal }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$20/<-6/ {Wait until pc ready }
$3e/$0f/$d3/$a0/ $7c/ $f6/$50/ $d3/$a1/ {Send low nibble }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$28/<-6/ {... }
$3e/$0f/$d3/$a0/$3e/$40 /$d3/$a1/
$fb);
End;
Procedure JoyBlockSend(BuffAddr:Integer);
Var BlockAddress :Integer;
Begin
BlockAddress := BuffAddr;
Inline
(
$F3/$DD/$2a/BlockAddress/$DD/$4E/$0/$DD/$46/$1/$DD/$7E/$0/$67/$CB/
$3C/$CB/$3C/$CB/$3C/$CB/$3C/$E6/$F/$6F/
$3E/$0/$D3/$99/$D9/$D9/$3E/$40/$D3/$99/$DD/$7E/$0/$D9/$D9/$D3/$98/
{The code above just writes current byte value on vram addr 0 }
$3E/$E/$D3/$A0/$DB/
$A2/$CB/$47/$20/$FA/$3E/$F/$D3/$A0/$7D/$F6/$50/$D3/$A1/$3E/$E/
$D3/$A0/$DB/$A2/$CB/$47/$28/$FA/$3E/$F/$D3/$A0/$3E/$40/$D3/$A1/
$3E/$E/$D3/$A0/$DB/$A2/$CB/$47/$20/$FA/$3E/$F/$D3/$A0/$7C/$F6/
$50/$D3/$A1/$3E/$E/$D3/$A0/$DB/$A2/$CB/$47/$28/$FA/$3E/$F/$D3/
$A0/$3E/$40/$D3/$A1/$DD/$23/$B/$78/$B1/$20/$8F/$FB
);
End;
Function JoyByteReceive:Byte;
Var Value :Byte;
Begin
Inline($f3/
$3e/$0f/$d3/$a0/ $3e /$5f/ $d3/$a1/
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$20/<-6/ {Pc data ready ? }
$3e/$0f/$d3/$a0/ $3e /$1f/ $d3/$a1/ {Set joy port 1 fo
reading }
$3e/$0e/$d3/$a0/$db/$a2/$e6/$0f/$6f / {Read and store data in L}
$3e/$0f/$d3/$a0/$3e/$4f /$d3/$a1/ {Msx has read data }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$28/<-6/
$3e/$0f/$d3/$a0/ $3e /$5f/ $d3/$a1/
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$20/<-6/ {Pc data ready ? }
$3e/$0f/$d3/$a0/ $3e /$1f/ $d3/$a1/ {Set joy port 1 fo
reading }
$3e/$0e/$d3/$a0/$db/$a2/
$cb/$27/$cb/$27/$cb/$27/$cb/$27/$67 / {Read and store data in H }
$3e/$0f/$d3/$a0/$3e/$4f /$d3/$a1/ {Msx has read data }
$3e/$0e/$d3/$a0/$db/$a2/$cb/$47/$28/<-6/
$7c/$85/$32/Value /
$3e/0/$d3/$99/$d9/$d9/$3e/$40/$d3/$99/$d9/$d9/$3a/Value /$d3/$98/
{The code above just writes current byte value on vram addr 0 }
$fb);
JoyByteReceive := Value;
End;
Procedure JoyBlockReceive(BufAddr:Integer);
Var Len,i :Integer;
Begin
Len := JoyByteReceive + 256*JoyByteReceive;
Mem[BufAddr] := Lo(Len);
Mem[BufAddr+1] := Hi(Len);
For i := 1 To Len+3 Do Mem[BufAddr+1+i] :=JoyByteReceive;
End;
----- cut here ---
Pc-code
---- cut here ---
{PC_MSX:PAS by Kari Lammassaari 1996-98}
{The routines are to be used with the msx equivalent routines in
msx_pc.inc }
{REM IMPORTANT ! The block send/receive-routines expect the two first
received/sent byte contain the total lenght of the block including
those two first bytes !}
{This file contains following procedures and functions:
- Function ParallelByteReceive:Byte;
- Procedure ParallelBlockReceive(DataBlock:DataBlockType);
- Procedure ParallelByteSend(Value:Byte);
- Procedure ParallelBlockSend(Var DataBlock:DataBlockType);
and following type definition:
}
Type DataBlockType = Record
Len :Word;
ChkSum :Word;
DataId :Char;
Data :Array[0..255] Of Byte;
End;
{
Function GetNibble:Byte;
Begin
Port[$37a] :=205;
Repeat Until ((Port[$379] And 128) = 0) Or KeyPressed;
GetNibble := (Port[$379] shr 3) And 15;
Port[$37a] :=204;
Repeat Until ((Port[$379] And 128) = 128) Or KeyPressed;
End;
}
Function GetNibble:Byte; Assembler;
Asm
Mov dx,$37a ;{Ctrl-port of parallel port }
Mov al,205 ;{Normal value after reset is 204}
Out dx,al ;{Pc is ready to receive }
Mov dx,$379 ;{Status port in dx }
@Loop1: ;
In al,dx ;{Is data ready }
and al,128
Jnz @Loop1 ;
push ax ;{ Let signals be settled }
pop ax ;
In al,dx ;{Reread data }
Shr al,3 ;{Shift bits to the right edge}
And al,15 ;{Mask off the upper nibble }
Push ax ;
Mov dx,$37a ;{Ctrl-port }
Mov al,204 ;{Normal after-reset value }
Out dx,al ;{Data received }
Mov dx,$379 ;{Status port }
@Loop2:
In al,dx ;{Has Msx received message ? }
and al,128 ;
Jz @Loop2 ;
Pop Ax ;
End;
Function ParallelByteReceive:Byte;
Begin
ParallelByteReceive := 16 * GetNibble + GetNibble;
End;
Procedure ParallelBlockReceive(Var DataBlock:DataBlockType);
Var i :Word;
Begin
DataBlock.Len := ParallelByteReceive*256 + ParallelByteReceive -5;
{Do not include the header bytes }
DataBlock.ChkSum := ParallelByteReceive*256 + ParallelByteReceive;
DataBlock.DataId := Chr(ParallelByteReceive);
i:=0;
While i < DataBlock.Len Do
Begin
DataBlock.Data[i]:= ParallelByteReceive;
Inc(i);
End;
End;
{
Procedure PutNibble(Value:Byte);
Begin
Repeat Until ((Port[$379] And 128) = 0) Or KeyPressed;
Port[$378] := Value And 15;
Port[$37a] := 205 ;
Repeat Until ((Port[$379] And 128) = 128) Or KeyPressed;
Port[$37a] := 204 ;
End;
}
Procedure PutNibble(Value:Byte);Assembler;
Asm
mov dx,$379 ;
@loop1:
in al,dx ;
and al,128 ;
jnz @loop1 ;
mov dx,$378 ;
mov al,Byte Ptr [Value] ;
out dx,al
mov dx,$37a ;
mov al,205 ;
out dx,al ;
mov dx,$379
@loop2:
in al,dx ;
and al,128 ;
jz @loop2 ;
mov dx,$37a
mov al,204
out dx,al
end;
Procedure ParallelByteSend(Value:Byte);
Begin
PutNibble(Value And 15);
PutNibble(Value shr 4 );
End;
Procedure ParallelBlockSend(Var DataBlock:DataBlockType);
Var Counter :Word;
Ptr :^Byte;
Begin
Ptr := Addr(DataBlock);
For Counter := 1 to DataBlock.Len + 5 Do
Begin
ParallelByteSend(Ptr^);
Inc(Ptr);
End;
End;
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the
quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
****
