attimer(4) [netbsd man page]
ATTIMER(4) BSD Kernel Interfaces Manual ATTIMER(4) NAME
attimer -- AT Timer (8253) driver SYNOPSIS
attimer* at acpi? attimer0 at isa? DESCRIPTION
The attimer driver handles the so-called AT Timer device, initially found as chip model 8253. It is used as the main counter for the clock on the i386 port, but also offers control over the pitch of the PC speaker. The attimer driver currently only implements the access to the ISA register ``TIMER1'' which controls the pitch of the PC speaker, and should be configured along with pcppi(4) to be of any actual use. SEE ALSO
acpi(4), isa(4), pcppi(4) BSD
March 22, 2005 BSD
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PCPPI(4) BSD Kernel Interfaces Manual PCPPI(4) 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) BSD
March 22, 2005 BSD