Mystery IC: Allen Bradley 314B102

[tony duell]

> 
> Tony, good advice but probably more work than I'm inclined to put in.

What I have suggested would take about 10 minutes tops. It has probably
taken me longer to type this message than it would take me to figure
that out.

> As you said there were many interfaces with different standards -
> different polarities and timing - and either way it's quite likely

Based on Brent's schematic and the date I wonder if it is similar
to the HP9866 interface. The connector is wrong, but the signals
(7 data lines, strobe, ready, paper out) are right. And it is a 
machine that was around at the time. Possibly this was to get
letter quality output that didn't fade from some machine designed
to use that printer.

> this will never work with a standard modern parallel port without
> building some converter, after first finding out what has to be
> converted and designing it!

Probably just a matter of inverting some of the signal lines (i.e. '04s)

-tony