Write a program in assembly language TASM only when user ent

Solution

stack segment

stack ends

data segment
msg1 db \'please enter A, B or C only $\'
data ends

printmsg macro msg
lea dx,msg
mov ah,09h
int 21h
endm

code segment

assume cs:code,ds:data,ss:stack

start:
mov ax,data
mov ds,ax
main proc

mov ah, 1 ; get user input
int 21h
mov bl, al ; save input to bl

cmp bl,\'A\'
jne nota
mov ah,2
mov dl,\'D\'
int 21h

nota:
cmp bl,\'B\'
jne notb
mov ah,2
mov dl,\'E\'
int 21h

notb:
cmp bl,\'C\'
jne notc
mov ah,2
mov dl,\'F\'
int 21h

notc:
printmsg msg1

mov ah,4ch ; return control to dos
int 21h
main endp
code ends
end start