; this is 16b real mode code, intel synthax (typically used with nasm)
; zero 36b starting at address 0x40:0x1a


 xor ax,ax
 mov al, 0x40
 mov ds, ax
 mov al, 0x1a
 mov si, ax
 mov cx, 0x24

 xor al, al

cleanall:
 mov [ds:si], ax
 loop cleanall