Contributor: GREG ESTABROOKS
{
SE>I have Borland Pascal 7.0 and I ran acrost the idea of 286 and 8088 code
SE>specs in a program. How can you detect for a 286 CPU and if present,
SE>switch $G to $G+ ?
There should be a program somewhere in your TP disks that has a routine
that detects whether or not a 286+ CPU is pressent. Unfortunately you
can't have it change the status of $G. It's either on or off. You can
either leave it on , detect CPU type, if its the wrong type leave a
mesage and abort the program or not use the $G directive at all.
Here is a simple CPU detection routine in case you can't find the one I
mentioned:
}
CONST
CPU :ARRAY[0..3] Of STRING[13] =('8088/V20','80286',
'80386/80486','80486');
FUNCTION CpuType :WORD; ASSEMBLER;
{ Returns a value depending on the type of CPU }
{ 0 = 8088/V20 or compatible }
{ 1 =わ 80286 2 =わ 80386/80486+ }
ASM
Xor DX,DX { Clear DX }
Push DX
PopF { Clear Flags }
PushF
Pop AX { Load Cleared Flags }
And AX,0ドルF000 { Check hi bits for F0h }
Cmp AX,0ドルF000
Je @Quit { Quit if 8088 }
Inc DX
Mov AX,0ドルF000 { Now Check For 80286 }
Push AX
PopF
PushF
Pop AX
And AX,0ドルF000 { If The top 4 bits aren't set }
Jz @Quit { Its a 80286+ }
Inc DX { Else its a 80386 or better }
@Quit:
Mov AX,DX { Return Result in AX }
END;{CpuType}
BEGIN
Writeln('Your CPU is a ',CPU[CpuType]);
END.