assume cs:code
data segment
db "Beginner's All-purpose Symbolic Instruction Code.",0
data ends
code segment
begin:
mov ax,data
mov ds,ax
call letterc
mov ax,4c00h
int 21h
letterc:
mov si,0
s:
cmp byte ptr ds:[si],0
je ok
cmp byte ptr ds:[si],61h
jnb k
inc si
jmp s
k:
cmp byte ptr ds:[si],7ah
jna t
inc si
jmp s
t:
sub byte ptr ds:[si],20h
inc si
jmp s
ok:
ret
code ends
end begin |
