.sect .text; .sect .rom; .sect .data; .sect .bss
.sect .text
.define .loi
! #bytes in cx
! source address in si
.loi:
pop bx
mov dx,cx
sar cx,1
jnb 1f
xorb ah,ah
lodsb
push ax
jmp bx
1:
sub sp,dx
mov di,sp
rep movs