Mystery IC: Allen Bradley 314B102

[Mike Ross]

On Tue, Dec 15, 2015 at 1:21 PM, Fred Cisin <cisin at xenosoft.com> wrote:
> On Tue, 15 Dec 2015, Mike Ross wrote:

>> That was my conclusion too. The old Western I/O ads I've seen
>> definitely refer to it as having an 'ASCII' or 'parallel' interface.
>> Assuming they only ever made the two models; I suppose it *could* be
>> some variant of RS232, with very non-standard pinouts - but the ads
>> are specific; they made a smart terminal with 6800 CPU & serial
>> interface, and a dumb printer with an 'ASCII parallel' interface. And
>> that's all I have to go on, beyond prodding the hardware.
>
>
> REMEMBER, "ASCII parallel" does NOT necessarily mean "centronics-style", as
> was used on TRS80, IBM PC, etc.  "Centronics-style"  was a good system, but
> it was NOT the only one.
> "ASCII parallel" could just as easily mean SEVEN bit, with a bit or two in
> each direction for handshaking.   "ASCII" was SEVEN bits, not EIGHT.

I guessed that might be the case... any suggestions for what were
common pinouts and signals used? I can analyze 'backwards', testing
possible suggestions, as fast or faster than I can do it 'forwards',
trying to recreate a schematic from examination of the hardware. It
sounds a lot like what we have here. But I'm not certain a modern
standard parallel port can ever be trivially adapted to drive this
thing...

> There was a time, 35 years ago, when "standard parallel" was an oxymoron.
>
>> leads, 7 lines... I'd expect to see 8 data lines all going to the same
>> place if it was anything resembling standard Centronics but with a
>> weird pinout. So I'm scratching my head still over just exactly what
>> it was supposed to hook up to.
>
>
> something other than "Centronics"?

I thought Centronics dated back to early 1970s - not always in the
standard 'modern' form, but in general principles with same signaling
and strobing of data.

Thanks for input!

Mike

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