Contec BUF-PCI(PC) User Manual page 58

Programming
Description of accessing I/O ports on the BUS-PCI(PCI) board
50
When executing function BufPciOpen, the BUS-PCI(PCI) board of
a specified board ID secures the I/O port address (BufPciIoAddress)
and interrupt request level (BufPciIrqLevel) assigned from the PCI
BIOS in particular buffers. BufPciIoAddress and BufPciIrqLevel
are used for accessing the BUS-PCI(PCI) board with function
BufPciXxxx.
If the BUS-PCI(PCI) board for the specified board ID does not exist,
return an error.
When executing function BufPciOpen, initialize the bus signal in
the I/O expansion unit.
Set the I/O wait to "2 wait" and the refresh signal to "No output."
At the initial Open when using with multiple programs, set the
interrupt request mask register and reset the interrupt request status.
outpw(BufPciIoAddress + 0xf8, 0xffff);
outpw(BufPciIoAddress + 0xfa, 0xffff);
outpw(BufPciIoAddress + 0xfc, 0x0002);
For more information, see the section on I/O port addresses.
BUF-PCI(PC), BUF-PCI(98)
Sets interrupt request mask.
Resets interrupt request status.
Sets I/O wait and refresh signals.