bits 16 ; boot sectors run in real mode
org 7c00h ; boot sector is loaded at 0x7c00
+_start
+ mov di, printing_numbers
+ call print
+
+ or bl, 1
mov dx, 0DEADh ; number to print
- mov cl, 0 ; column
- mov ch, 0 ; row
call print_word
+
+ mov di, space
+ call print
+
+ xor bl, bl
mov dx, 0BEEFh
- mov cl, 0
- mov ch, 1
call print_word
- jmp $
+ mov di, waiting
+ call print
+
+ mov di, keystroke
+ mov bl, 1
+
+.loop
+ mov ah, 0
+ int 16h
+ cmp ah, 1Ch
+ je .enterpressed
+ jmp .continue
+ cmp ah, 0Eh
+ je .backspace
+ jmp .continue
+.enterpressed
+ pusha
+ mov ah, 0Eh
+ mov al, 0Dh
+ int 10h
+ mov al, 0Ah
+ int 10h
+ popa
+ jmp .loop
+.backspace
+ pusha
+ mov ah, 03h
+ mov bh, 0
+ int 10h
+ dec dl
+ mov ah, 02h
+ int 10h
+ mov ah, 0Eh
+ mov al, ' '
+ int 10h
+ mov ah, 02h
+ int 10h
+ popa
+ jmp .loop
+.continue
+ mov [keystroke], al
+ call print
+ jmp .loop
+
+printing_numbers db "Printing some random hex numbers", 0
+waiting db "I await keystrokes", 0
+keystroke db "$", 0
+space db " ", 0
%include "print.s"