Re: ID: Cards...

[Tony Cianfaglione <ab616@chebucto.ns.ca>]

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.

----------------------------------------

On 26 Jul 2003, Michael Black wrote:

> 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
> 
> 
> 
> > -----------------------------
> > 
> > On 25 Jul 2003, Michael J. Mahon wrote:
> > 
> >> >MMI DSC Board (1982)
> >> 
> >> Rings a bell, but I can't place it...  Could you describe it and its chips?
> > 
> 
> 
> 
>