8086 - Beep until get input

Question

I am new to assembly language and i want to create a program with 8086 assembly. (emu8086) So the program is supposed to continuously beep until key E is pressed. now the first way is to use a simple jump to check input each time and this is the code that i came up with :

    macro beep
    mov dl,7h
    mov ah,2
    int 21h
endm

.model small
.stack 64

.code :  

lp:

beep

mov ah,1
int 21h

cmp al,'e'
je end

jmp lp

end:
mov ah,4ch
int 21h

Now what i want to achieve is that beeping must be continuous and i dont want the user to do input in each cycle. Something like multi threading in C which beeping is done in another thread.

is that even possible in 8086 ?

Answer 1

BIOS function 01h checks if a key is pending.

• If not, you immediately re-beep.
• If a key is present, you fetch it with BIOS function 00h, and if it's not 'e', you continue to re-beep.

This is probably the simplest solution to get a continuous beep until the character 'e' is pressed.

lp:
 beep
 mov ah, 01h
 int 16h      ;Gives ZF
 jz  lp       ;No key waiting
 mov ah, 00h
 int 16h      ;Gives AX
 cmp al, 'e'
 jne lp
 mov ax, 4C00h
 int 21h