Assembly program help

Question

I have a program that is supposed to clear the screen and print my name, then new line and print my name again. but when i run it nothing shows up. just program teminated normally. I'm doing this in windows command prompt using debug.

    call 010E
    call 0125
    call 012D
    call 0125
    int 20

    push ax     #clearscreen(010E)
    push bx
    push cx
    push dx
    xor al, al
    xor cx, cx
    mov dh, 18
    mov dl, 4f
    mov bh, 07
    mov ah, 06
    int 20
    pop dx
    pop cx
    pop bx
    pop ax
    ret

    mov dx, 0200    #printline(0125)
    mov ah, 09
    int 21
    ret

    push ax         #new line( 012D)
    push dx
    mov ah, 02
    mov dl, 0d
    int 21
    mov dl, 0a
    int 21,
    pop dx
    pop ax
    ret

    DB' Antarr$ #(0200)

Answer 1

Your first and most obvious error is calling int 20, Terminate Program, instead of BIOS interrupt int 10 withing the clearscreen function.

EDIT: but why don't you use an assembler for this? Try NASM for example. Also, this program: Tech, will help you with finding the right DOS or BIOS function.

Answer 2

You are trying to call a hardware interrupt (int 20). Because of protected mode, you're not going to be able to enter mode 20. In other words, Windows is going to block you from talking to the hardware directly.