.sect .text; .sect .rom; .sect .data; .sect .bss .define .cmu4 .sect .text .cmu4: pop bx ! return address pop cx pop dx pop ax push si mov si,sp xchg bx,2(si) pop si cmp bx,dx ja 1f jb 2f cmp ax,cx ja 1f je 3f 2: mov ax,-1 ret 3: xor ax,ax ret 1: mov ax,1 ret