Notes

.model small
.stack 100h
.data
titleMsg db 'AR 101 LABORATORY ACTIVITY$'
welcomeMsg db 'Welcome to Computer Architecture and Organization$'
passPrompt db 'Enter Password: $'
correctPass db '1234$'
wrongMsg db 'Incorrect Password! Press any key to try again...$'
input db 6 dup(?) ; input buffer
selected db 1 ; currently selected menu item (1-7)
menuTitle db ' M E N U$'
ex1 db 'Exercise 1 - Conditional Maximum$'
ex2 db 'Exercise 2 - Simple Arithmetic$'
ex3 db 'Exercise 3 - String Reversal$'
ex4 db 'Exercise 4 - Palindrome Checker$'
ex5 db 'Exercise 5 - Fibonacci Sequence$'
ex6 db 'Exercise 6 - Simple Calculator$'
ex7 db 'Exercise 7 - Bitwise Operations$'
.code
main proc
mov ax, @data
mov ds, ax

password_screen:
; --- SET TEXT MODE ---
mov ax, 03h
int 10h

; --- DISPLAY TITLE ---
mov ah, 02h
mov bh, 0
mov dh, 5
mov dl, 25
int 10h
mov ah, 09h
lea dx, titleMsg
int 21h

; --- DISPLAY WELCOME MESSAGE ---
mov ah, 02h
mov bh, 0
mov dh, 7
mov dl, 10
int 10h
mov ah, 09h
lea dx, welcomeMsg
int 21h

; --- ENTER PASSWORD PROMPT ---
mov ah, 02h
mov bh, 0
mov dh, 10
mov dl, 20
int 10h
mov ah, 09h
lea dx, passPrompt
int 21h

; --- CLEAR INPUT BUFFER ---
lea si, input
mov cx, 6
clear_input:
mov byte ptr [si], '$'
inc si
loop clear_input

; --- READ PASSWORD WITH * MASK ---
lea si, input
mov cx, 0
readLoop:
mov ah, 08h
int 21h

; Check for backspace
cmp al, 08h
je handle_backspace

cmp al, 0Dh
je doneRead

cmp cx, 4 ; Only accept 4 characters
jae readLoop

mov [si], al
inc si
inc cx
mov ah, 02h
mov dl, '*'
int 21h
jmp readLoop

handle_backspace:
cmp cx, 0 ; Check if there's anything to delete
je readLoop
dec si
dec cx
mov byte ptr [si], '$'
; Move cursor back and erase character
mov ah, 02h
mov dl, 08h ; backspace
int 21h
mov dl, ' ' ; space to clear
int 21h
mov dl, 08h ; backspace again
int 21h
jmp readLoop

doneRead:
mov byte ptr [si], '$'

; --- COMPARE PASSWORD ---
lea si, input
lea di, correctPass
mov cx, 0 ; counter for matched characters

compareLoop:
mov al, [si]
mov bl, [di]

; Check if we reached end of correctPass
cmp bl, '$'
je check_length

; Check if we reached end of input too early
cmp al, '$'
je wrong_pass

; Compare characters
cmp al, bl
jne wrong_pass

inc si
inc di
inc cx
jmp compareLoop

check_length:
; Make sure input also ends here
mov al, [si]
cmp al, '$'
je pass_ok ; Both strings ended at same point
jmp wrong_pass ; Input is longer than correct password

wrong_pass:
; Display error message
mov ah, 02h
mov bh, 0
mov dh, 12
mov dl, 10
int 10h
mov ah, 09h
lea dx, wrongMsg
int 21h

; Wait for any key press
mov ah, 00h
int 16h

; Go back to password screen
jmp password_screen

; --- CORRECT PASSWORD ---
pass_ok:
; Clear screen
mov ax, 03h
int 10h
; =========================
; DRAW 4-COLOR QUADRANTS
; =========================
; Top-left (YELLOW)
mov ah, 06h
mov al, 0
mov bh, 0EEh ; bright yellow background
mov ch, 0
mov cl, 0
mov dh, 12
mov dl, 39
int 10h
; Top-right (RED)
mov ah, 06h
mov al, 0
mov bh, 044h ; red background
mov ch, 0
mov cl, 40
mov dh, 12
mov dl, 79
int 10h
; Bottom-left (RED)
mov ah, 06h
mov al, 0
mov bh, 044h ; red background
mov ch, 13
mov cl, 0
mov dh, 24
mov dl, 39
int 10h
; Bottom-right (YELLOW)
mov ah, 06h
mov al, 0
mov bh, 0EEh ; bright yellow background
mov ch, 13
mov cl, 40
mov dh, 24
mov dl, 79
int 10h
; =========================
; BLUE BOX OVERLAY (LARGER, CENTERED)
; =========================
mov ah, 06h
mov al, 0
mov bh, 1Fh ; blue background, white text
mov ch, 2 ; start row (higher up)
mov cl, 17 ; start column
mov dh, 20 ; end row (lower down)
mov dl, 62 ; end column
int 10h

menu_loop:
; Redraw blue box to clear previous highlights
mov ah, 06h
mov al, 0
mov bh, 1Fh ; blue background, white text
mov ch, 2
mov cl, 17
mov dh, 20
mov dl, 62
int 10h

; Display menu items with highlight
call display_menu

; Wait for arrow key input
mov ah, 00h
int 16h

; Check for Enter key
cmp ah, 1Ch ; Enter scan code
je menu_selected

; Check for Up arrow
cmp ah, 48h ; Up arrow scan code
je move_up

; Check for Down arrow
cmp ah, 50h ; Down arrow scan code
je move_down

jmp menu_loop

move_up:
mov al, selected
cmp al, 1
je menu_loop ; Already at top
dec selected
jmp menu_loop

move_down:
mov al, selected
cmp al, 7 ; Changed to 7
je menu_loop ; Already at bottom
inc selected
jmp menu_loop

menu_selected:
; Here you can add code to handle the selected menu item
; For now, just exit
jmp stop_here

display_menu proc
; Menu title
mov ah, 02h
mov bh, 0
mov dh, 4
mov dl, 38
int 10h
mov ah, 09h
lea dx, menuTitle
int 21h

; Exercise 1
mov al, selected
cmp al, 1
je draw_highlight1
jmp draw_normal1
draw_highlight1:
; Draw highlight background
mov ah, 06h
mov al, 0
mov bh, 70h ; black on white
mov ch, 6
mov cl, 19
mov dh, 6
mov dl, 60
int 10h
draw_normal1:
mov ah, 02h
mov bh, 0
mov dh, 6
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex1
int 21h

; Exercise 2
mov al, selected
cmp al, 2
je draw_highlight2
jmp draw_normal2
draw_highlight2:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 8
mov cl, 19
mov dh, 8
mov dl, 60
int 10h
draw_normal2:
mov ah, 02h
mov bh, 0
mov dh, 8
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex2
int 21h

; Exercise 3
mov al, selected
cmp al, 3
je draw_highlight3
jmp draw_normal3
draw_highlight3:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 10
mov cl, 19
mov dh, 10
mov dl, 60
int 10h
draw_normal3:
mov ah, 02h
mov bh, 0
mov dh, 10
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex3
int 21h

; Exercise 4
mov al, selected
cmp al, 4
je draw_highlight4
jmp draw_normal4
draw_highlight4:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 12
mov cl, 19
mov dh, 12
mov dl, 60
int 10h
draw_normal4:
mov ah, 02h
mov bh, 0
mov dh, 12
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex4
int 21h

; Exercise 5
mov al, selected
cmp al, 5
je draw_highlight5
jmp draw_normal5
draw_highlight5:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 14
mov cl, 19
mov dh, 14
mov dl, 60
int 10h
draw_normal5:
mov ah, 02h
mov bh, 0
mov dh, 14
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex5
int 21h

; Exercise 6
mov al, selected
cmp al, 6
je draw_highlight6
jmp draw_normal6
draw_highlight6:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 16
mov cl, 19
mov dh, 16
mov dl, 60
int 10h
draw_normal6:
mov ah, 02h
mov bh, 0
mov dh, 16
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex6
int 21h

; Exercise 7
mov al, selected
cmp al, 7
je draw_highlight7
jmp draw_normal7
draw_highlight7:
mov ah, 06h
mov al, 0
mov bh, 70h
mov ch, 18
mov cl, 19
mov dh, 18
mov dl, 60
int 10h
draw_normal7:
mov ah, 02h
mov bh, 0
mov dh, 18
mov dl, 22
int 10h
mov ah, 09h
lea dx, ex7
int 21h

ret
display_menu endp

stop_here:
mov ah, 4Ch
int 21h

end main