Re: PCB identifcation

Uh, you got all that from the pictures? :)

Won't know more details until the boards show up. As far as I can tell the
boards are devoid of all ICs, so datecodes might be tricky.

I *can* say with some certainty that it is not a prototype Demon sound
board. I have schematics for the Demon sound board BTW.

tom

Zonn writes:

> On Thu, 27 May 2004 17:20:03 -0500, Tom McClintock <tomm@mgcap.com> wrote:
>
>>getting closer I suspect. :) I honestly don't know what it is, but it is
>>from Cinematronics and not someone's basement (although I suppose those
>>could be one and the same at some point in history).
>>
>>What about this one?
>>http://www.ionpool.net/DCP01174.jpg
>
> The first one's a bit strange. The empty large socket (is that really a socket,
> it's hard to tell?) in the upper right corner is the size of a DAC80, and this
> seems to be validated by the precision resistors just below it that would be
> used to set offset and gain.
>
> Two of the transistor look like they're just LED drivers.
>
> It's hard to tell where the I/O on this thing is. The larger molex looks like
> the power connector, you can see a couple of large wires heading towards the
> power resistors which drop some voltage before the two voltage regulators.
>
> Maybe the smaller molex connector went to a joystick, it *almost* looks like
> this could have been a prototype Tailgunner joystick adapter that would work on
> any monitor. I say *almost* because there's no digital inputs to set the
> supposed DAC80.
>
> So maybe the DAC80 socket really went to some ribbon cable, that...
>
> Ok, (I'm thinking as I'm typing), how about this is a daughter board that would
> connect to the DAC80 on a standard cinematronics monitor that would add joystick
> support to it? It's not quite complete however. There would need to be a
> ribbon cable going to the monitor, perhaps the socket is really the bottom part
> of one of those ribbon cable connectors that has been torn in two? Either way
> there would either need to be a pass through daughter board on the monitor (it
> would plug into the DAC80 socket, and the DAC80 would plug into it), or the
> ribbon cable would need to be solder directly underneath the DAC80. The 2 LED's
> could indicate the state of the comparators (one for each axis). The third
> transistor could be used as a voltage converter, converting the +/- 15v to the
> 0v to 5v needed for the CCPU's "EI" input -- however the resistor network in
> front of it seems like a little overkill for this.
>
> This doesn't quite seem right either since you only need a few lines from the
> DAC80 to do joystick control, then again you don't need 14 pins sockets for
> those op-amps either. But if it's an audio board it's missing the amplifier
> section, those two power devices are definitely voltage regulators as indicated
> by the capacitors around them.
>
> ----------
>
> The 2nd picture looks like a full CPU board, Z80 maybe?
>
> Socket D2 would be the CPU, though I don't see a crystal, maybe it was plugged
> in like the R/C network at A2. E2,F2,E3,F3 would be address and data bus
> drivers. G2,H2,J2 would be RAM, while K2 would be some type of I/O / timer /
> uart / kind of chip. (If it's a uart, then L2 and L3 would be the voltage
> converters -- though if this were the case, the power supply is short one
> voltage since you'd normally need three voltages, though you could probably get
> by with +5v and some negative voltage less than -5v). The rest of the board is
> glue logic and possibly some parallel I/O.
>
> The header at A1 does a ribbon cable jump over to the ROM board. The other two
> headers is where the CPU talks to the outside world. If this is CCPU related,
> then it only talked to the CCPU, it wasn't part of it. It could be that the I/O
> thingy was a GI sound chip and this is a massively complicated sound board.
> Maybe a prototype Demon sound card?
>
> -Zonn
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Received on Thu May 27 22:24:19 2004