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)