{######################## Analog Game Port #################################
# Example how to use an analog game port as analog input #
# Copyright 1998 Segment B.V., Beek, The Netherlands #
############################################################################}
program gametest;
uses crt;
const g_port = $201; {game port's base address}
max = 550; {holds maximum value}
offset = 50; {holds minimum value}
nr = 5; {number of samples to average}
{######################### Measurement function ###########################}
function measure (var Value: integer; Input, Nr: integer):boolean;
{ 'Value' contains the result of the measurement
'Input' selects the input channel
'Nr' determines the number of samples used for averaging}
var i, counter, game : integer;
bitgame : boolean;
dummy : longint;
begin
if ((nr > 100) or (input>4) or (input<1)) then
begin
gotoxy(5,20);
writeln('Error!! Wrong parameter in measurement function');
measure:=false;
end
else
begin
value:=0;
dummy:=0;
if input=4 then input:=8;
if input=3 then input:=4;
for i:=0 to (Nr-1) do
begin
counter:=0;
bitgame:=true;
port[g_port]:=0;
while bitgame do
begin
game:=port[g_port];
bitgame:=(((game and input)=input) and
(counter<((max*2)+offset)));
counter:=counter+1;
end;
counter:=counter-offset;
dummy:=(dummy + counter);
delay(1);
end;
value:=trunc (dummy/Nr);
if ((value> (max * 2)) or (value<0)) then
begin
if value<0 then value:=-9999
else value:=9999;
measure:=false;
end
else measure:=true;
end;
end; {function}
{######################## Input fire button status #########################}
procedure buttons(var key1, key2, key3, key4: boolean);
{returns boolean values to show fire button status}
{keyx := true if button pressed}
var game : integer;
begin
game := port[g_port];
key1:=((game and 128)<>128);
key2:=((game and 64)<>64);
key3:=((game and 32)<>32);
key4:=((game and 16)<>16);
end; {procedure}
{######################## Main Program #####################################}
var connect, i : integer;
value1 : integer;
returnm, t1, t2, t3, t4 : boolean;
e : char;
value2 : real;
begin
ClrScr;
gotoxy(5,3);
writeln('Analog game port input');
gotoxy(5,23);
writeln('Press "e" to interrupt this program');
gotoxy(1,8);
writeln (' INPUT 1:');
writeln (' INPUT 2:');
writeln (' INPUT 3:');
writeln (' INPUT 4:');
gotoxy(5,15);
write('digital inputs:');
gotoxy(12,17);
write('1:');
gotoxy(22,17);
write('2:');
gotoxy(32,17);
write('3:');
gotoxy(42,17);
write('4:');
while e<>'e' do
begin
if keypressed then e:=readkey
else
begin
for i:=0 to 3 do
begin
returnm := measure(value1, (i+1), Nr);
if returnm then
begin
gotoxy(30,(8+i));
write(' ');
gotoxy(30,(8+i));
write(value1);
gotoxy(35,(8+i));
write(' number of program loops ');
end
else
begin
gotoxy(30,(8+i));
if value1<0 then
write('---- negative overflow ')
else
write('++++ positive overflow ');
end;
end;
buttons(t1,t2,t3,t4);
gotoxy(15,17);
if t1 = true then
write(' ON')
else
write('OFF');
gotoxy(25,17);
if t2 = true then
write(' ON')
else
write('OFF');
gotoxy(35,17);
if t3 = true then
write(' ON')
else
write('OFF');
gotoxy(45,17);
if t4 = true then
write(' ON')
else
write('OFF');
end; {else}
end; {while}
ClrScr;
end.