PCPPI(4)                  OpenBSD Programmer's Manual                 PCPPI(4)

NAME
     pcppi - PC (ISA) control and timer port driver

SYNOPSIS
     pcppi*   at isa?
     spkr0    at pcppi?
     midi*    at pcppi?

DESCRIPTION
     The pcppi driver handles resource allocation and device attachment for
     the ports related to the ISA speaker in the traditional PC/AT ``design''.
     These are the ``system control port'' (which was implemented by the 8255
     ``PPI'' in the XT, hence the name of this driver) at I/O address 0x61 and
     the first 8253 timer at 0x40-0x43.

     The pcppi driver provides its child devices with the ability to output
     simple tones through the PC speaker.  The speaker(4) and midi(4) devices
     use this to synthesize sounds.  It also provides helper functions to the
     pckbd(4) driver as a substitute for a ``keyboard beep'', because the PC
     keyboard hardware doesn't provide this.

SEE ALSO
     intro(4), isa(4), midi(4), pckbd(4), speaker(4)

OpenBSD 4.7                    January 26, 2008                              1
