--- Tony Duell <ard_at_p850ug1.demon.co.uk> wrote:
> >
> >
> > I had this idea for a keyboard adapter for classic machines, but I
> > don't understand the 40-pin "keyboard BIOS" microcontroller well
> > enough to know if it's possible...
>
> I am not sure where the term 'keyboard BIOS' came from, but it can go
> back there :-)
I know it's a pre-programmed microcontroller, but in the U.S., if you
go to a PeeCee shop, that is what they call it.
> You may not need the PC-compatible 8042 chip for this. Information on the
> serial interface to the keyboard exists as well.
True, it does, but I was investigating if I could use an existing
microcontroller for that or not.
> And I would have thought you could program just about any
> microcontroller to talk to the keyboard on one side and
> the RS232 line on the other
Yes, but since this 8042 is already set up to do it, *and* it takes
care of any undocumented or poorly documented "features", I was
thinking it could be a faster/simpler solution.
> > I know that the 6402 serial chip can be strapped to operate in a
> > dumb converter mode...
>
> Although I normally do things like that, this is one time when a
> microcontroller would be more efficient, I think.
I was attempting to use the 8042 as the microcontroller in this
circuit without an additional microcontroller that I would have
had to program and debug.
> You really want an IBM PC/AT Techref....
OK. That's exactly the kind of answer I was looking for.
> You could _trivially_ hang the 8042 keyboard interface chip off the bus
> of either of those CPUs.
It's an alternative I'm considering. All I really need is a way to
use a cheap keyboard, occasionally, not full time, to play with the
innards of what is, essentially, an I/O board with an embedded
microprocessor. I am already going to have a UART, so I wanted to
explore the possibility of using the recieve side to listen to a
keyboard with a minimal amount of stuff in between.
Thanks,
-ethan
__________________________________________________
Do You Yahoo!?
Yahoo! Finance - Get real-time stock quotes
http://finance.yahoo.com
Received on Wed Aug 28 2002 - 22:22:00 BST