[Coladam] eBay auction

Joe Blenkle jblenkle at sacnews.net
Sun Jun 14 22:37:49 CEST 2009


So has it been decided who, if anyone, is going to bid on this?

----- Original Message ----- 
From: "Rich Drushel" <drushel at apk.net>
To: <coladam at adamcon.org>
Sent: Sunday, June 14, 2009 9:01 AM
Subject: Re: [Coladam] eBay auction


>
> On Sun, June 14, 2009 12:18 am, Geoff Oltmans wrote:
>
>> I asked the seller for more detailed pics. He's put a couple more up.
>
>     I looked, they confirm that there are trimpots present, other stuff
> for some kind of analog circuit.
>
>> Looks like there are more components underneath the ribbon cable. One
>> part is an LM567CN, which is described as a tone decoder. I also got
>> him to take some closeups of the four chips in the center of the
>> board. It looks like there might be a 5th underneath the ribbon.
>
>     "Tone decoder"...hmmm...then possibly "TAPE SIM" means that the
> analog circuitry section (near the DB-37 and above/under the ribbon
> cable) is generating/decoding test tones at a particular frequency,
> like what is encoding the data on a DDP.  If you have ever listened
> to a tape in an audio tape deck (remembering to drill out certain
> holes in the case so it will fit alignment pegs that audio tape decks
> have), there are some pure tones, plus staticky-sounding stuff, for
> each data block.  Sample DDP data in lieu of an actual tape drive...
> an emulator for the read/write and/or servo boards (see my schematics
> page).
>
>     Not enough of an electrical engineer to know from just the chips
> that are present; I am speculating.  Hey, maybe this is part of the
> prototyping stuff for the "wafer" or "stringy-floppy" tape drives that
> were never used...explaining why none of the chips match those used
> in the tape drive daughter boards.  Remember, for the tape drives,
> the ADAMnet side (6801 and support chips) are on the ADAM logic board;
> the servo and read/write boards are in the tape drive unit.
>
>     *Dr. D.*
>
> -- 
> Richard F. Drushel, Ph.D.            | "They fell:  for Heaven to them no 
> hope
> Department of Biology                |  imparts / Who hear not for the 
> beating
> Case Western Reserve University      |  of their hearts."
> Cleveland, Ohio  44106-7080  U.S.A.  |         -- Edgar Allan Poe, 
> "Al-Aaraaf"
>
>
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