assume cs:code
data segment
db "Beginner's All-purpose Symbolic Instruction Code.",0
data ends
code segment
start: mov ax,data
mov ds,ax
mov si,0
call letterc
mov ax,4c00h
int 21h
letterc: mov cl,[si]
mov ch,0
jcxz ok
cmp cl,61h
jb s0
cmp cl,7ah
ja s0
and cl,11011111b
mov [si],cl
s0: inc si
jmp letterc
ok: ret
code ends
end start |
