[08.12.2011 16:26:42] CRUP: .model tiny
.code
org 100h
start:
jmp main
oldint09h dw 0000h, 0000h
newint09h:
push AX BX ES
in AL, 60h
cmp AL, 53h
jne quitint09h
mov BX, 0040h
mov ES, BX
mov BX, 0017h
mov AL, ES:[BX]
and AL, 00001100b
cmp AL, 00001100b
jne quitint09h
mov AL, 20h
out 20h, AL
pop ES BX AX
iret
quitint09h:
pop ES BX AX
jmp dword ptr CS:[oldint09h]
main:
mov AH, 35h
mov AL, 09h
int 21h
mov CS:[oldint09h], BX
mov CS:[oldint09h + 0002h], ES
mov AH, 25h
mov AL, 09h
mov DX, offset newint09h
int 21h
mov DX, offset main
int 27h
end start