dump:
  push ax
  push cx
  push dx
  push bx
  mov al, 0x0A
  call putc
  mov al, 0x0D
  call putc
  mov cx, 4
.loop_line:
  push cx
  push bx
  mov ax, bx
  call print16
  mov al, ':'
  call putc
  mov al, ' '
  call putc
  mov cx, 0x8
.loop_bin:
  mov ax, [bx]
  xchg al, ah
  inc bx
  inc bx
  call print16
  mov dl, ' '
  call CONOUT
  loop .loop_bin
  pop bx
  mov cx, 0x10
.loop_ascii:
  mov dl, '.'
  cmp byte [bx], 0x20
  jc .print
  cmp byte [bx], 0x80
  jnc .print
  mov dl, [bx]
.print:
  inc bx
  call CONOUT
  loop .loop_ascii
  pop cx
  mov dl, 0x0A
  call CONOUT
  mov dl, 0x0D
  call CONOUT
  loop .loop_line
  pop bx
  pop dx
  pop cx
  pop ax
  ret