Re: Clock Card?

[Don Bruder <dakidd@sonic.net>]

In article <PYqdneEA3bDUU_WiXTWJig@comcast.com>,
 "Bill Garber" <willy46pa@comcast.net> wrote:

> Another and I have determined that this is some form
> of clock card. It has "IDS" formed into the face of the
> card using the trace material but that part is not connected
> to any of the real and actual traces. I have 2 of these cards
> and would like to use one or both. If anyone has one of these
> and has software to configure it, or would like to accept one
> for study and possibly engineer some software for use with it,
> I would be happy to allow them to keep the card as payment
> for doing so. A layout of the card is available at the link below.
> 
> http://garberstreet.netfirms.com/MysteryCard.jpg


Bill:

FWIW, I'd have to agree that it's a clock card - It took some hunting, 
but google finally turned up some info on a couple of the non-74LSXXX 
chips, all of which I see on your diagram are very generic chips seen 
anywhere interface work is being done. First and foremost of the 
"informative" results is the MSM5832RS chip. The best info I can find on 
it right now is that it was used as the heart of a critter called "The 
Timekeeper", which was a RTC card developed for the "ACT Sirius 1" 
computer (a machine I'd never heard of until now - apparently it 
ran/runs MS-DOS (Version 2.0, no less!!!!) and/or CP/M on an 8088 chip).

The very little information I can find suggests that the 5832 is a 
microprocessor in and of itelf, with timekeeping as its dedicated 
function, and gets interfaced to the host system, whatever that might 
be, through a PIA or PPI chip such as an 8255 (in the case of The 
Timekeeper) or the MC6821CPDS that happens to be a PIA, and lives on 
your cards. 

I suspect the "best target" to shoot at on this thing is going to be  
trying to dump the EPROM to possibly see what the devil is going on in 
there. Even before I'd do that, though, I'd try slapping it into Slot 4 
(clock cards used to be recommended for slot 4, in the days before mouse 
cards were preferred there, if I recall rightly) and try firing up the 
newest version of ProDOS you can come up with. *MANY* of the clock cards 
sold for the Apple, especially after the introduction of ProDOS, did 
their best to be "Thunderclock compatible" so that time and money didn't 
need to be wasted on developing a new driver for them. The Thunderclock 
driver is built into ProDOS, of course, so if this card, whatever it 
actually is, is one of the "I'll pretend to be a Thunderclock so you 
don't need to write a driver" types, it should "just work" once plugged 
in and powered up. Setting the date/time/etc on it may be a problem 
without a separate utility, however... I can't recall whether the 
Thunderclock driver included "set-the-clock" functionality.

Also, the part you have labeled "pot" probably isn't... I'm betting that 
it's actually a trimmer capacitor, which, with a crystal, another 
(fixed) capacitor, a couple of resistors, and part of the 74LS04, would 
make up the local oscillator. The trimmer would allow fine-tuning of the 
frequency in case of any "drift" in the crystal or the other capacitor. 
It's also possible that this trimmer (and the crystal and other assorted 
items right near it) feeds directly into the 5832, allowing it to do its 
own clock-frequency generation. Without seeing actual traces (and 
support parts) I can't be much more specific than that, though...

Also, you might want to take a look here:
<http://home.hccnet.nl/h.v.d.heijden/rtc-e.html>

That seems to be a page devoted to a 5832 & 6821 PIA-based RTC add-on 
board for the "Acorn A.T.O.M.", a 6502 based machine that *I THINK* was 
something of an Apple II clone. Mention is made of software being 
available, but in skimming around, I didn't see the software itself. 
Maybe I missed it? Maybe it's gone? You tell me! :)

Best of luck...

-- 
Don Bruder -  dakidd@sonic.net <--- Preferred Email - SpamAssassinated.
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