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Unit Com;
Interface
Const
B_110 = 1040;
B_150 = 768;
B_300 = 384;
B_600 = 192;
B_1200 = 96;
B_2400 = 48;
B_4800 = 24;
B_9600 = 12;
B_19200 = 6;
B_38400 = 3;
B_57600 = 2;
B_115200 = 1;
Bits_5 = 0;
Bits_6 = 1;
Bits_7 = 2;
Bits_8 = 3;
Stops_1 = 0;
Stops_2 = 4;
Parity_No = 0;
Parity_Even = $18;
Parity_Odd = 8;
Var
ComBasePort : Array [1..4] of Word;
Function OpenCom (ComNo : Byte; BaudRate : Word; Config : Byte;
BufSize : Word) : Boolean;
Function CloseCom (ComNo : Byte) : Boolean;
Function ReadCom (ComNo : Byte; Var Value) : Boolean;
Function BlockReadCom (ComNo : Byte; Var Buf; Size : Word) : Boolean;
Function WriteCom (ComNo : Byte; Var Value) : Boolean;
Function BlockWriteCom (ComNo : Byte; Var Buf; Size : Word) : Boolean;
Function ReceivedFromCOM (ComNo : Byte) : Word;
Implementation
Uses DOS;
Type
TComBuf = Array [0..65527] of Byte;
PComBuf = ^TComBuf;
Const
IO_Reg = 0;
Lo_Div = 0;
Hi_Div = 1;
Int_Reg = 1;
Int_Id = 2;
Control = 3;
Modem = 4;
Status = 5;
MStatus = 6;
IRQAlreadyUsed : Array [3..4] of Boolean = (False, False);
Var
OldIRQHandler : Array [3..4] of Pointer;
IntMask : Array [3..4] of Byte;
BasePort : Array [3..4] of Word;
PComBufs : Array [3..4] of PComBuf;
ComBufSize : Array [3..4] of Word;
Head, Tail, _Received : Array [3..4] of Word;
Procedure NewIRQ3Handler; Interrupt;
Var
X : Byte;
Label
LEnd;
Begin
If _Received[3] = ComBufSize[3] then Goto LEnd;
X := Port[BasePort[3]+IO_Reg];
(PComBufs[3])^[Tail[3]] := X;
Inc (Tail[3]);
If Tail[3] = ComBufSize[3] then Tail[3] := 0;
Inc (_Received[3]);
LEnd:
Port[$20] := $20
End;
Procedure NewIRQ4Handler; Interrupt;
Var
X : Byte;
Label
LEnd;
Begin
If _Received[4] = ComBufSize[4] then Goto LEnd;
X := Port[BasePort[4]+IO_Reg];
(PComBufs[4])^[Tail[4]] := X;
Inc (Tail[4]);
If Tail[4] = ComBufSize[4] then Tail[4] := 0;
Inc (_Received[4]);
LEnd:
Port[$20] := $20
End;
Function OpenCom (ComNo : Byte; BaudRate : Word; Config : Byte;
BufSize : Word) : Boolean;
Var
Result : Boolean;
Base : Word;
IRQ : Byte;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
Base := ComBasePort[ComNo];
If Base = 0 then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If IRQAlreadyUsed[IRQ] then Goto LEnd;
Port[Base+Control] := $80;
Port[Base+Lo_Div] := BaudRate and $FF;
Port[Base+Hi_Div] := BaudRate shr 8;
Port[Base+Control] := Config;
Port[Base+Modem] := 8;
Port[Base+Int_Reg] := 1;
BasePort[IRQ] := Base;
Head[IRQ] := 0;
Tail[IRQ] := 0;
_Received[IRQ] := 0;
ComBufSize[IRQ] := BufSize;
GetMem (PComBufs[IRQ], BufSize);
GetIntVec (8+IRQ, OldIRQHandler[IRQ]);
If IRQ=3 then SetIntVec (8+IRQ, @NewIRQ3Handler)
Else SetIntVec (8+IRQ, @NewIRQ4Handler);
IntMask[IRQ] := Port[$21];
If IRQ=3 then Port[$21] := IntMask[3] and $F7
Else Port[$21] := IntMask[4] and $EF;
IRQAlreadyUsed[IRQ] := True;
Result := True;
LEnd:
OpenCom := Result
End;
Function CloseCom (ComNo : Byte) : Boolean;
Var
Result : Boolean;
IRQ : Byte;
Base : Word;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
Base := ComBasePort[ComNo];
If Base = 0 then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
Port[Base+Modem] := 0;
Port[Base+Int_Reg] := 0;
Port[$21] := IntMask[IRQ];
SetIntVec (8+IRQ, OldIRQHandler[IRQ]);
FreeMem (PComBufs[IRQ], ComBufSize[IRQ]);
IRQAlreadyUsed[IRQ] := False;
Result := True;
LEnd:
CloseCom := Result
End;
Function ReadCom (ComNo : Byte; Var Value) : Boolean;
Var
Result : Boolean;
IRQ : Byte;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
If _Received[IRQ] = 0 then Goto LEnd;
Byte(Value) := (PComBufs[IRQ])^[Head[IRQ]];
Inc (Head[IRQ]);
If Head[IRQ] = ComBufSize[IRQ] then Head[IRQ] := 0;
Dec (_Received[IRQ]);
Result := True;
LEnd:
ReadCOM := Result
End;
Function BlockReadCom (ComNo : Byte; Var Buf; Size : Word) : Boolean;
Var
Result : Boolean;
IRQ : Byte;
_Head,
BufSize : Word;
From : Pointer;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
If _Received[IRQ] = 0 then Goto LEnd;
_Head := Head[IRQ];
BufSize := ComBufSize[IRQ];
From := PComBufs[IRQ];
Asm
Push DS
LES DI, Buf
LDS SI, From
Mov CX, Size
Mov BX, _Head
Mov DX, BufSize
CLD
@cycle:
Mov AL, DS:[SI+BX]
STOSB
Inc BX
Cmp BX, DX
JC @right
Xor BX, BX
@right:
Loop @cycle
Mov _Head, BX
Pop DS
End;
Head[IRQ] := _Head;
Dec (_Received[IRQ], Size);
Result := True;
LEnd:
BlockReadCOM := Result
End;
Function WriteCom (ComNo : Byte; Var Value) : Boolean;
Var
Result : Boolean;
IRQ : Byte;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
While Port[BasePort[IRQ]+Status] and $20 = 0 do;
Asm CLI End;
Port[BasePort[IRQ]+IO_Reg] := Byte(Value);
Asm STI End;
Result := True;
LEnd:
WriteCOM := Result
End;
Function BlockWriteCom (ComNo : Byte; Var Buf; Size : Word) : Boolean;
Var
Result : Boolean;
IRQ : Byte;
IOPort, StatusPort : Word;
Label
LEnd;
Begin
Result := False;
If not ComNo In [1..4] then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
StatusPort := BasePort[IRQ]+Status;
IOPort := BasePort[IRQ]+IO_Reg;
Asm
LES DI, Buf
Mov CX, Size
Mov DX, StatusPort
Mov BX, IOPort
@wait:
In AL, DX
Test AL, 20h
JZ @wait
Xchg DX, BX
Mov AL, ES:[DI]
CLI
Out DX, AL
STI
Inc DI
Xchg DX, BX
Loop @wait
End;
Result := True;
LEnd:
BlockWriteCOM := Result
End;
Function ReceivedFromCOM (ComNo : Byte) : Word;
Var
IRQ : Byte;
Result : Word;
Label
LEnd;
Begin
Result := 0;
If not ComNo In [1..4] then Goto LEnd;
If ComNo and 1 = 0 then IRQ := 3
Else IRQ := 4;
If not IRQAlreadyUsed[IRQ] then Goto LEnd;
Result := _Received[IRQ];
LEnd:
ReceivedFromCOM := Result
End;
Begin
ComBasePort[1] := MemW[Seg0040:0];
ComBasePort[2] := MemW[Seg0040:2];
ComBasePort[3] := MemW[Seg0040:4];
ComBasePort[4] := MemW[Seg0040:6]
End.
Писал не я, так что претензии по поводу отсутствия комментариев не принимаются :)
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