Category : Pascal Source Code
Archive   : QWIK5X.ZIP
Filename : TIMERD12.INC

{ Timerd12.inc - DOS event timer ver 1.2, 01-30-87 }
{ by Jim H. LeMay CIS: 76011,217 }
{ A 24 hour timer with resolution of 1/18.2... seconds to measure elapsed time
in seconds. Works on all IBM compatible machines and is interchangeable with
TIMERH.INC. If TIMERH.INC can work on your machine, then use it; if not,
TIMERD.INC will. Both also compile with Turbo87.
TO TEST: Remove the curly braces around "BEGIN ... END". Compile and Run.
TO USE: Place "Timer(Start)" and "Timer(Stop)" as desired in your program.
"ElapsedTime" gives result in seconds. }

type
StartStop = (Start, Stop, SetRead, ReadRead);
TicksArray = array [1..5] of byte;
var
t0,t1,t2,TicksPerDay,TicksPerSec,ElapsedTime: real;
T1array,T2array: TicksArray;
const
FirstTime: boolean = true;

procedure GetTicks (VAR Ticks: TicksArray);
begin
Inline(
$1E { push ds ;Save Turbo DS}
/$31/$C0 { xor ax,ax ;Set ax=0}
/$8E/$D8 { mov ds,ax ;Segment for DOS timer}
/$BE/$6C/$04 { mov si,$046C ;Offset for DOS timer}
/$C4/$7E/ /$FC { cld ;Set direction forward}
/$AB { stosw ;Store zero}
/$FA { cli ;Clear interrupts}
/$A4 { movsb ;Copy DOS low byte}
/$A5 { movsw ;Copy DOS mid word}
/$FB { sti ;Allow interrupts}
/$1F { pop ds ;Restore Turbo DS}
)
end;

function ArrayToReal (Ticks: TicksArray): real;
begin
ArrayToReal := ((Ticks[5]*256.0) + Ticks[4])*256 + Ticks[3]
end;

procedure TimerInit;
begin
FirstTime := false;
TicksPerDay := 1573040.0; { DOS timer ticks/day. }
TicksPerSec := TicksPerDay/86400.0;
t0 := 0.0 { only needed for TIMERH.INC }
end;

procedure Timer (SS: StartStop);
begin
case SS of
Start: begin
if FirstTime then TimerInit;
ElapsedTime:=0;
GetTicks (T1array)
end;
Stop: begin
GetTicks (T2array);
t1 := ArrayToReal(T1array); { Convert AFTER the event! }
t2 := ArrayToReal(T2array);
if t2 ElapsedTime:= (t2-t1)/TicksPerSec { units of seconds }
end
end { end case }
end;

{
var ch: char;

BEGIN
ClrScr;
Writeln('Press any key for a lap; to stop.');
Timer (Start);
repeat
write(chr(16));
read(Kbd,ch);
Timer (Stop);
writeln ('E.T. =',ElapsedTime:10:2,' secs: ticks2=',t2:12:0);
GotoXY (24,wherey); WriteLn ('-ticks1=',t1:12:0);
GotoXY (21,wherey); WriteLn ('E.T. ticks=',(t2-t1):12:0);
writeln;
until ch = chr(27)
END.
}