Re: Apple II+ keyboard weirdness (help with repair)

["Rob Diehl" <rkcdiehl1@bellsouth.net>]

Thanks for the help. Unfortunately the file seems to be corrupt (both WinRAR
and gzip refuse to extract it). Tried to get it with both IE and wget. Do
you have another copy, or else one that isn't in gzip format? Also, your web
server seems to be setting the MIME type to Quicktime for some reason.

BTW, I should mention that the voltages I measured were while no keys were
being pressed, so I wouldn't think the pins would be toggling states, but
I'm also not sure how the keyboard on the Apple is designed so maybe it
does?

Thanks again.

-Rob

> I don't know. Don't forget though that the keyboard encoder scans the
> key matrix, so many of the pins will be rapidly toggling between their
> high and low states. On a meter this may look like a strange voltage.
> You really need a logic analyser, or at least a simple logic probe to
> tell what's really going on.
>
> > 2) Where can I get a detailed pin description of the keyboard
> > controller board? The Apple II Redbook seems to have everything
> > covered in great detail except for the keyboard.
>
> This I can help with :-) I have a copy of the later Apple II Reference
> Manual which covers the Apple II and II+. It has the keyboard encoder
> circuit in it, which I have scanned and uploaded to <http://homepages.
> ihug.co.nz/
> ~rojaws/Apple II keyboard.tiff.gz>