{$A+,B+,D-,E+,F+,I+,L+,N-,O-,R-,S+,V-}

unit tmpcom;

interface

uses crt,dos;

var

tmpcom_BIOS_port_table:array[1..2] of integer absolute $0040:0000;

const

I8088_IMR=$21;

tmpcom_buffer_max=5120;

type

tmpcom_portrec=

record

RTB, { receive / transmit buffers }

IER, { interrupt enable register }

IIR, { interrupt identification register }

LCR, { line control register }

MCR, { modem control register }

LSR, { line status register }

MSR:integer; { modem status register }

end;

var

tmpcom_saveoldvec:pointer;

tmpcom_ports:tmpcom_portrec;

tmpcom_base:integer;

tmpcom_irq,

tmpcom_port:byte;

tmpcom_open_flag:boolean;

tmpcom_buffer:array[0..tmpcom_buffer_max] of byte;

tmpcom_buffer_head,

tmpcom_buffer_tail,

tmpcom_buffer_used:integer;

tmpcom_outcharacter:char;

tmpcom_outgoingnow:boolean;

mpcoder:boolean;

mpcode:array[1..6] of byte;

procedure tmpcom_clear_errors;

procedure tmpcom_setdtr(b:boolean);

procedure tmpcom_closeport(ddtr:boolean);

procedure tmpcom_resetport(comport:byte; baudrate:longint; parity:char;

wordsize,stopbits:byte);

procedure tmpcom_openport(comport:byte; baudrate:longint; parity:char;

wordsize,stopbits:byte);

procedure tmpcom_initvars;

function tmpcom_receive(var c:char):boolean;

procedure tmpcom_sendno(c:char);

procedure tmpcom_send(c:char);

implementation

procedure tmpcom_clear_errors;

var i,j:integer;

begin

inline($FA); { cli }

{ disable baud rate bs... }

i:=port[tmpcom_ports.LCR] and $7F;

port[tmpcom_ports.LCR]:=i;

i:=port[tmpcom_ports.LSR]; { read LSR to reset errors }

i:=port[tmpcom_ports.RTB]; { read RTB in case it contains a chr }

{ enable the IRQ line (3/4) on the 8259 controller }

i:=((port[I8088_IMR]) and ((1 shl tmpcom_irq) xor $00FF));

port[I8088_IMR]:=i;

{ enable data-available interrupt --

transmit-register-empty interrupt is set by tmpcom_send(. }

port[tmpcom_ports.IER]:=$01;

{ enable OUT2, RTS, and DTR }

port[tmpcom_ports.MCR]:=$0B;

inline($FB); { sti }

end;

procedure tmpcom_setdtr(b:boolean);

var bb:byte;

begin

bb:=port[tmpcom_ports.MCR] and $FE;

if (b) then inc(bb);

port[tmpcom_ports.MCR]:=bb;

end;

procedure tmpcom_closeport(ddtr:boolean);

var i,j:integer;

begin

if (tmpcom_open_flag) then begin

inline($FA); { cli }

{ disable the IRQ line (3/4) on the 8259 controller }

i:=((port[I8088_IMR]) or (1 shl tmpcom_irq));

port[I8088_IMR]:=i;

{ disable data-available interrupt (along with all other interrupts) }

port[tmpcom_ports.IER]:=$00;

{ disable OUT2, and DTR if ddtr=TRUE }

i:=((port[tmpcom_ports.MCR]) and ($F7));

port[tmpcom_ports.MCR]:=i;

inline($FB); { sti }

{ reset interrupt vector to original setting }

setintvec(tmpcom_irq+8,tmpcom_saveoldvec);

tmpcom_open_flag:=FALSE;

end;

end;

function iii(i:integer):byte;

var j:integer;

begin

j:=tmpcom_buffer_tail-i;

if (j<0) then inc(j,tmpcom_buffer_max+1);

iii:=tmpcom_buffer[j];

end;

procedure checkmpcode;

var i:integer;

begin

inline($FA);

if ((iii(1)=254) and (iii(2)=253)) then

if ((iii(9)=1) and (iii(10)=2) and (iii(11)=1)) then begin

mpcoder:=TRUE;

for i:=1 to 6 do mpcode[7-i]:=iii(i+2);

tmpcom_buffer_head:=0;

tmpcom_buffer_tail:=tmpcom_buffer_head;

end;

inline($FB);

end;

procedure tmpcom_isr(flags,cs,ip,ax,bx,cx,dx,si,di,ds,es,bp:word); interrupt;

var dxx,i:integer;

bb:byte;

label iisr1,iisr2;

begin

inline($FB);

iisr1:

dxx:=port[tmpcom_ports.IIR];

if (dxx and $01<>$00) then goto iisr2;

case (dxx and $06) of

0:;

2:begin

if (tmpcom_outgoingnow) then begin

i:=port[tmpcom_ports.MSR];

port[tmpcom_ports.RTB]:=ord(tmpcom_outcharacter);

tmpcom_outgoingnow:=FALSE;

end;

port[tmpcom_ports.IER]:=port[tmpcom_ports.IER] and $FD;{ turn off TRE }

end;

4:begin

bb:=port[tmpcom_ports.RTB];

tmpcom_buffer[tmpcom_buffer_head]:=bb;

inc(tmpcom_buffer_head);

if (tmpcom_buffer_head>tmpcom_buffer_max) then

tmpcom_buffer_head:=0;

if (bb=255) then checkmpcode;

end;

6:;

end;

goto iisr1;

iisr2:

port[$20]:=$20;

end;

procedure tmpcom_resetport(comport:byte; baudrate:longint; parity:char;

wordsize,stopbits:byte);

const

tmpcom_num_bauds=10;

tmpcom_baud_table:

array[1..tmpcom_num_bauds] of record baud,bits:word; end

= ((baud:110; bits:$00), (baud:150; bits:$20),

(baud:300; bits:$40), (baud:600; bits:$60),

(baud:1200; bits:$80), (baud:2400; bits:$A0),

(baud:4800; bits:$C0), (baud:9600; bits:$E0),

(baud:19200; bits:$E0), (baud:38400; bits:$E0));

var regs:registers;

comparm,i:integer;

begin

tmpcom_buffer_head:=0;

tmpcom_buffer_tail:=0;

{ set up baud rate bits }

i:=0;

repeat inc(i)

until ((tmpcom_baud_table[i].baud=baudrate) or (i=tmpcom_num_bauds));

comparm:=tmpcom_baud_table[i].bits;

case upcase(parity) of

'E':comparm:=comparm or $18;

'O':comparm:=comparm or $08;

end;

if (wordsize=7) then comparm:=comparm or $02 else comparm:=comparm or $03;

if (stopbits=2) then comparm:=comparm or $04;

regs.ax:=comparm and $00FF;

regs.dx:=tmpcom_port-1; { comport }

intr($14,regs);

end;

procedure tmpcom_openport(comport:byte; baudrate:longint; parity:char;

wordsize,stopbits:byte);

begin

if (tmpcom_open_flag) then tmpcom_closeport(FALSE);

if ((comport=2) and (tmpcom_BIOS_port_table[2]<>0)) then begin

tmpcom_base:=$2f8;

tmpcom_port:=2; tmpcom_irq:=3;

end else begin

tmpcom_base:=$3f8;

tmpcom_port:=1; tmpcom_irq:=4;

end;

with tmpcom_ports do begin

RTB:=tmpcom_base;

IER:=tmpcom_base+$01;

IIR:=tmpcom_base+$02;

LCR:=tmpcom_base+$03;

MCR:=tmpcom_base+$04;

LSR:=tmpcom_base+$05;

MSR:=tmpcom_base+$06;

end;

(* { if the impossible has happened, get the heck outta here... }

if (port[tmpcom_ports.IIR] and $F8<>0) then exit;*)

tmpcom_resetport(comport,baudrate,parity,wordsize,stopbits);

getintvec(tmpcom_irq+8,tmpcom_saveoldvec);

setintvec(tmpcom_irq+8,@tmpcom_isr);

tmpcom_resetport(comport,baudrate,parity,wordsize,stopbits);

tmpcom_clear_errors;

tmpcom_open_flag:=TRUE;

end;

procedure tmpcom_initvars;

begin

tmpcom_base:=$3f8;

tmpcom_irq:=4;

tmpcom_port:=1;

tmpcom_open_flag:=FALSE;

tmpcom_buffer_head:=0;

tmpcom_buffer_tail:=0;

tmpcom_buffer_used:=0;

tmpcom_outcharacter:=#0;

tmpcom_outgoingnow:=FALSE;

end;

function tmpcom_receive(var c:char):boolean;

begin

c:=#0;

if (tmpcom_buffer_head<>tmpcom_buffer_tail) then begin

inline($FA);

c:=chr(tmpcom_buffer[tmpcom_buffer_tail]);

tmpcom_buffer_tail:=(tmpcom_buffer_tail+1) mod (tmpcom_buffer_max+1);

inline($FB);

tmpcom_receive:=TRUE;

end else

tmpcom_receive:=FALSE;

end;

procedure tmpcom_sendno(c:char);

var i:integer;

begin

i:=port[tmpcom_ports.MSR];

while (port[tmpcom_ports.LSR] and $20=0) do ;

port[tmpcom_ports.RTB]:=ord(c);

end;

procedure tmpcom_send(c:char);

var lng:longint;

i:integer;

begin

inline($FB);

lng:=0; while ((tmpcom_outgoingnow) and (lng<500000)) do inc(lng);

if (lng>=500000) then begin

inline($FA); tmpcom_outgoingnow:=FALSE;

{ tmpcom_clear_errors;}

inline($FA); delay(100); inline($FB);

end;

{ enable transmit-register-empty interrupt }

inline($FA);

tmpcom_outcharacter:=c;

tmpcom_outgoingnow:=TRUE;

i:=port[tmpcom_ports.IER];

if (i and $02<>$02) then begin

i:=i or $02;

port[tmpcom_ports.IER]:=i;

end;

inline($FB);

(* inline($FA);

tmpcom_obuffer[tmpcom_obuffer_tail]:=c;

tmpcom_obuffer_tail:=(tmpcom_obuffer_tail+1) mod (tmpcom_obuffer_max+1);

inline($FB);*)

end;

begin

mpcoder:=FALSE;

tmpcom_open_flag:=FALSE;

end.