.model small

.stack 100h

.data

buffer db 101 dup(0)

quitstring db "quit"

.code

print_literal MACRO lit

local string, end1

push ax

push dx

push ds

mov ax, cs

mov ds, ax

mov dx, offset string

call output_string

pop ds

pop dx

pop ax

jmp end1

string db lit,'$'

end1:

ENDM

readstring MACRO str

push dx

push ax

mov dx, offset str

mov al, 100

call input_string

pop ax

pop dx

ENDM

printstring MACRO str

push dx

mov dx, offset str

call output_string

pop dx

ENDM

crlf MACRO

push ax

push dx

mov ah, 02H

mov dl, 0DH

int 21H

mov dl, 0AH

int 21H

pop dx

pop ax

ENDM

output_string PROC NEAR

push ax

push dx

mov ah, 09h

int 21h

pop dx

pop ax

ret

output_string ENDP

input_string PROC NEAR

push dx

push cx

push si

push di

push es

push ds

mov di, dx

mov cx, ds

mov es, cx

mov cx, cs

mov ds, cx

mov cs:formatted_buffer[0], al

mov dx, offset formatted_buffer

mov ah, 0Ah

int 21h

mov si, offset formatted_buffer

add si, 2

mov cl, cs:formatted_buffer[1]

mov ch, 0

rep movsb

mov byte ptr es:[di], '$'

mov al, cs:formatted_buffer[1]

pop ds

pop es

pop di

pop si

pop cx

pop dx

ret

formatted_buffer db 257 dup(0)

input_string ENDP

quit PROC NEAR

mov ah, 4Ch

int 21h

quit ENDP

.startup

mov ax, @data

mov ds, ax

mov es, ax

print_literal "Input a string: "

readstring buffer

crlf

print_literal "The string you typed in all lowercase is: "

main1:

mov ah, 6

mov dl, 0ffH

int 21H

je main1

cmp al, 3

je main2

l1:

lodsb

add al, 20h

stosb

loop l1

skip:

mov dl, al

int 21h

jmp main1

main2:

.exit

.exit

END