File:Codepage-437.png

; PRINT ENTIRE OF CODE PAGE 437 TO THE SCREEN
; (NASM Source)

_start:
    ; Set to 0
    xor ax, ax
    xor bx, bx
    xor cx, cx
    xor dx, dx

    mov ah, 0x5 ; Select active display page al
    mov al, 1
    int 0x10

    mov bh, 1   ; Page number
    mov ah, 0x2 ; Set cursor position to (dl, dh)
    int 0x10

    xor ax, ax
    ; For each character (0-255)
    loop:
        mov ah, 0xa ; Write character al at cursor position
        mov cx, 1   ; Write only once
        int 0x10
        inc dl      ; x++
        ; Create a newline every 32 characters
        test dl, 0x1f   ; if dl & 0x1f == 0
        jnz nonewline
            inc dh      ; y++
            xor dl, dl  ; x = 0
        nonewline:
        mov ah, 0x2 ; Set cursor position to (dl, dh)
        int 0x10
        inc al      ; al++
        test al, al ; if al != 0 goto loop
        jnz loop

hang:
    jmp hang

; Count up size of each section
%assign text_length ($-$$)

; Pad the boot sector out to 512 bytes
; All bytes are padded with nop, except the last to (0x55 0xaa).
times 510 - text_length nop

db 0x55, 0xaa