planet-strike/D3_ASM.ASM

67 lines
1.4 KiB
NASM
Raw Normal View History

2013-07-08 00:00:00 +00:00
; JABHACK.ASM
.386C
IDEAL
MODEL MEDIUM
EXTRN LDIV@:far
;============================================================================
DATASEG
;============================================================================
CODESEG
; Hacked up Juan Jimenez's code a bit to just return 386/not 386
PROC _CheckIs386
PUBLIC _CheckIs386
pushf ; Save flag registers, we use them here
xor ax,ax ; Clear AX and...
push ax ; ...push it onto the stack
popf ; Pop 0 into flag registers (all bits to 0),
pushf ; attempting to set bits 12-15 of flags to 0's
pop ax ; Recover the save flags
and ax,08000h ; If bits 12-15 of flags are set to
cmp ax,08000h ; zero then it's 8088/86 or 80188/186
jz not386
mov ax,07000h ; Try to set flag bits 12-14 to 1's
push ax ; Push the test value onto the stack
popf ; Pop it into the flag register
pushf ; Push it back onto the stack
pop ax ; Pop it into AX for check
and ax,07000h ; if bits 12-14 are cleared then
jz not386 ; the chip is an 80286
mov ax,1 ; We now assume it's a 80386 or better
popf
retf
not386:
xor ax,ax
popf
retf
ENDP
PROC _jabhack2
PUBLIC _jabhack2
push es
mov ax,seg LDIV@
mov es,ax
mov ax,9090h ;Two NOP's
mov [WORD FAR es:LDIV@],ax ;Patch over XOR AX,AX
mov [WORD FAR es:LDIV@+2],ax ;and over JMP SHORT COMMON
pop es
retf
ENDP
END