ID: Cards...

Can someone identify the cards below and exactly what they do?  There
doesn't seem to be too much on them, if anything, via search engines.

Mockingboard SSP2000 Rev. D (1985)

Soundchaser (Passport Design 1980-1)

MMI DSC Board (1982)

Thanks...

   You can find a couple of scans I did at:

                  www.chebucto.ca/~ab616/dsc-ic.gif
                  www.chebucto.ca/~ab616/dsc-rgb.tif

   They came out a little dark but turning up the screen brightness helped
with viewing.

   There is a DAC OUT/SPK OUT phono jack selectable with a jumper and an
AUX. OUT phono jack.

   The writing on it is: MMI DAC BOARD 1982 Temp{*filter*}Acuity Products Inc.

   The gold chip has AD558JD 8244 written on it.  The other log chip has
LM3900N RAYC8236 on it and the short chip has P231 LM 386N-1 on it.

  There is a slide volume(?) control at the back of the card.

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Tony Cianfaglione ( XXXX@XXXXX.COM ) writes:
Obviously, it's got some sort of digital to analog converter, with
speaker level output.

The LM386 is a small audio amplifier.

The LM3900 is a "quad norton amplifier", in other words, kind of like
op-amps and there are four of them in the package.

My first thought about the "558" is that it's the quad timer IC, which
is used (I think) in the Apple II for the joystick controller (and in
the IBM's joystick controller).

But that seems a bit off, and the "AD" prefix is Analog Devices;
not only did they not make timer ICs, but considering the labelling
of the board, that must be the DA converter.

A websearch verifies this, it's an 8-bit digital to analog converter
intended for interfacing to a CPU bus.

So it must be for generating sounds of some sort, be it music or
speech.  If those are the only ICs on the board, obviously it counts
on software to do much of the work.

I suppose the LM3900 is being used as a low pass filter, between the
DAC and the audio amplifier.

  Michael

Wow!  You know your stuff.

The DAC card, the Mockingboard and the Soundchaser are all in an
unenhanced 64k IIe.  The person I got it from said the stuff was in ther
when he got it and he never used it and didn't know what it was for.  I
wonder what the original use for all 3 cards together was for; if, indeed,
they were used together and not separately.

It would be great if someone with some time on their hands created a
reference website listing as many old A2 cards that could be identified
including scans, for posterity sake.

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