{
Date: 8/97
Purpose:Unit to control HW via the lpt port
Version: 1.0
Author:on1bew

}
unit hwi2c;

interface

uses dos;

{LPT port definition}
const lpt = $278; {lpt2}

procedure sdah;
procedure sdal;
procedure sclh;
procedure scll;
procedure rsda;
procedure rscl;
procedure powerchk(var power:boolean);

implementation

var SDA,SCL,power: boolean;

procedure sdah;
begin
 {Set SDA, select in}
 port[lpt+2] := port[lpt+2] or 8;
end;
procedure sdal;
begin
 {Reset SDA, select in}
 port[lpt+2] := port[lpt+2] and 247;
end;
procedure sclh;
begin
 {Set SCL, bit 7 }
 port[lpt+0] := port[lpt+0] and 127;
end;
procedure scll;
begin
 {Reset SCL, bit 7 }
 port[lpt+0] := port[lpt+0] or 128;
end;
procedure rsda;
begin
 {Read SDA}
 if port[lpt+1] and 8 = 8 then
 sda := true
 else
 sda := false;
end;
procedure rscl;
begin
 {Read SCL}
 if port[lpt+1] and 128 = 128 then
 scl := true
 else
 scl := false;
end;
procedure powerchk(var power:boolean);
begin
 {Read Power}
 if port[lpt+1] and 32 = 32 then
 power := true
 else
 power := false;
end;
end.
Terug