Contributor: LIN KE-FONG
{ Here is a small piece of code to detect if you are running under
a Linux's dosemu dos box.
Truly definitive version. .. update !!
Copyright (C) 1996 Lin Ke-Fong. Donated to public domain.
Feel free to ask me any questions at:
* lin.ke-fong@ace.epita.fr
* ke-fong.lin@nuxes.frmug.net.fr
}
function dosemu_Detect:boolean; assembler;
{ This function use two methods (which are "official") to detect dosemu.
First if dosemu is present, the BIOS date string at 0xF000:0xFFF5 should
be "02/25/93". Second interrupt $E6 called with ah = 0 should return $AA55
in ax register when in a dosemu dos box. Note that interrupt $E6 should
be "initialized" to point to an IRET instruction since it is often pointed
on nothing by BIOS.
}
asm
push ds
{ check for the BIOS date }
mov ax,$F000
mov ds,ax
mov bx,$FFF5
mov ax,'20'
cmp word ptr [bx],'20'
jne @no_dosemu
cmp word ptr [bx+2],'2/'
jne @no_dosemu
cmp word ptr [bx+4],'/5'
jne @no_dosemu
cmp word ptr [bx+6],'39'
jne @no_dosemu
{ initialize interrupt $E6 to an IRET }
xor ax,ax
mov ds,ax
mov bx,$E6 * 4
les di,[bx]
mov bl,es:[di]
mov byte ptr es:[di],$CF { put an iret instruction }
{ call the installation check interrupt (int $E6 with ah = 0) }
xor ah,ah
int $E6
mov es:[di],bl { restore the old instruction }
cmp ax,$AA55
jne @no_dosemu
mov ax,01h
jmp #end
#no_dosemu:
xor ax,ax
@end:
pop ds
end;
begin
if dosemu_Detect then
writeln('Hello dosemu ! and hello Linux !')
else
writeln('dosemu> MSDOS 7 :-)');
end.