Computer Control for the RX2
Julian Moss G4ILO

Program Listing


// basic utilities for RX2 control interface

unit RX2_Util;

interface

uses Windows;


// set address of game port (default '$201')

procedure SetPortAddr(const addr: string);

// get current channel number and signal presence

procedure GetStatus(var chan: Integer; var signal: Boolean);

// push button for t milliseconds

procedure PushButton(t: Integer);

implementation

uses SysUtils;

var

port_addr: Word;

function ReadPort: Byte;

begin

asm

mov dx,port_addr;

in al,dx

shr al,4

mov result,al

end;

end;



procedure SetPortAddr(const addr: string);

begin

port_addr := StrToInt(addr);

end;



procedure GetStatus(var chan: Integer; var signal: Boolean);

var

data: Byte;

const

chan_no: array[0..7] of Integer = (0,1,2,3,0,4,0,5);

begin

            data := ReadPort;

            signal := data > 8;

            chan := chan_no[data mod 8];

end;


procedure PushButton(t: Integer);

var

start: Integer;

begin

start := GetTickCount;

repeat

asm

                  	mov dx,port_addr

                  	mov al,1

                  	out dx,al

end;

until (GetTickCount - start) >= t;

end;

initialization

SetPortAddress('$201');

finalization

end.