if (dif & 800) then goto :pm
r vF0 csip
r VF1 fl
r sp -= 20
r cs ss
r ip sp
a cs:ip
 push ax
 mov ax, 1A00
 int 2F
 cmp al, FF
 pop ax
 int3
 nop
 .
g
r v0 fl.ZF
r sp += 20
r csip vF0
r fl vF1
goto :eof

:pm
r v0 0
; Cannot work in PM