cpu 8086
org 0x0100
  push cs
  pop es
  mov di, isr_dos_main
  mov ax, 0x21
  call intr_register

.loop:
  mov ah, 0x01
  int 0x21
  jmp .loop

  cli
.halt:
  hlt
  jmp .halt

isr_dos_main:
  cmp ah, 0x01
  je isr_getc
  cmp ah, 0x02
  je isr_putc
isr_error:
  push bp
  mov bp, sp
  ; set carry flag
  or WORD [SS:BP+6], 1
  pop bp
isr_return:
  iret

%include "intr.asm"
%include "drvtab.asm"

%include "chario.asm"

times 1000 db 0xEA