byte vic_border @ 53280

vector cinv @ 788
vector save_cinv

routine our_cinv
  inputs vic_border
  outputs vic_border
  trashes z, n
{
    inc vic_border
}

routine main
  inputs cinv, our_cinv
  outputs cinv, save_cinv
  trashes a, n, z
{
    with interrupts off {
        copy cinv, save_cinv
        copy our_cinv, cinv
    }
}