bits 32
org 0x7c00
jmp main
main:
;MEMBASE_LIMIT—Memory Base and Limit Register  (PCI-PCI—D30:F0)
  mov dx, 0xcf8
  mov eax,   0x8000f020
           ;      3 8 5
  out dx, eax

  mov dx, 0xcfc
  ; 100000 28 c
  ; 0123456789 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
  ; 1000000000  0  1  1  1  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
  mov eax, 11100011011100000001000100110000b
  out dx, eax
  in eax, dx
  and eax, 11100011011100000001000100110000b
  JE   done
  jmp end
  done:
  mov ah, 0x0e
  mov al, 'A'
  int 0x10
  end:
  mov ah, 0x0e
  mov al, 'C'
  int 0x10
  hlt
  nop
  nop
  nop
  nop
  times   510-($-$$) db 0
dw  0aa55h