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
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
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For one person, in the dark, where no one will ever know or see.'