Re: Accessing the Speaker of an IBM Model M keyboard

polemon wrote:

>> IIRC there were an unused pin ....

> The Speaker is not wired to the connector.
> It's wired to the controller in the keyboard.

Sorry I can't remember in detail and I lost my old IBM manuals.
Is it connection to the LED-driver ?
(five unused bits are there ... try at your own risk! )

All I found about speaker mentioned in the keyboard section
is the known story for the PC-internal speaker.

from RBIL-****ts:  bit0,1 [****t 0061h]
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Bitfields for KB controller ****t B [output]:
(Table P0392)
7 pulse to 1 for IRQ1 reset (PC,XT)
6-4 reserved
3 I/O channel parity check disable
2 RAM parity check disable
1 speaker data enable
0 timer 2 gate to speaker enable

Bitfields for KB controller ****t B [input]:
(Table P0393)
7 RAM parity error occurred
6 I/O channel parity error occurred
5 mirrors timer 2 output condition
4 toggles with each refresh request
3 NMI I/O channel check status
2 NMI parity check status
1 speaker data status
0 timer 2 clock gate to speaker status
Note: also sup****ted by OPTi 82C392
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Have you tried any Beep ?
__
wolfgang