NAME
pcppi —
PC (ISA) control port
driver
SYNOPSIS
pcppi* at acpi?
pcppi* at isa?
isabeep* at pcppi? (alpha only)
sysbeep* at pcppi? (i386 only)
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 IO address 0x61.
When associated with an
attimer(4) device, it is
possible to change the pitch of the sounds emitted through
pcppi.
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. The
isabeep(4) and
sysbeep(4) devices are helpers
which the
pckbd(4) driver uses as
a substitute for a “keyboard beep”, because the PC keyboard
hardware doesn't provide this.
SEE ALSO
acpi(4),
attimer(4),
isa(4),
midi(4),
pckbd(4),
speaker(4)