VT131 needs keyboard help

From: Christopher Smith <csmith_at_amdocs.com>
Date: Mon Jan 28 13:35:16 2002

> -----Original Message-----
> From: Ethan Dicks [mailto:erd_6502_at_yahoo.com]

> Keyboard error. It's _possible_ the keyboard error is in the VT131,
> but not as likely as in the keyboard. If you have a VT100 or VT101,

That was my thought...

> VT105, etc., you could test that keyboard in another terminal; but if
> you just have the VT131 as your sole example of DEC keyboards, that's
> a bit of a problem.

This is actually the only one I've ever met. I have seen pictures and
layout diagrams, though, and it _looks_ (IE the keys are the same) like
a VT100 keyboard. On the other hand, that other terminal _looked_ (The
case, etc, was nearly identical) like a VT100...

> If the label hasn't fallen off, ISTR that there was a paper sticker
> with the Digital logo and some numbers on the bottom.

Fallen off, or not there in the first place. :/

> It's possible, if you can't find a vendor description anywhere, that
> you picked up a keyboard for another terminal. Lots of folks
> used 1/4"
> jacks for keyboards in those days, even Apple (on the Lisa).

Yes, but again, it's not the jack that makes it look the same -- it
really does look like (at least a carbon copy of) a VT100 keyboard. See
my comment above about the other terminal, though. It certainly isn't a
Lisa keyboard. I have both the working machine, and a not-so-working
machine, each with the keyboard. Anyway, the apple markings would give
it away...

> If it's a DEC keyboard, it should be compatible. I am not aware of
> any major changes in keyboards, save VT100 vs LK201 and the like
> (different protocol, I presume; different appearance,
> different connector,
> etc.)

Yep. :) That's what I thought, anyway... So I'm assuming for now the
keyboard is bad, or incompatible. Perhaps I could modify it either way,
given the schematics for the keyboard...

> > Failing a way to positively identify the keyboard, are there any
> > common modes of failure along these lines?

> Dead chip in the keyboard, usually. We never fixed them when I used
> VT100s on a daily basis. We threw them into a box in the
> back room and
> grabbed a different (working) one from stock. The fact that we were
> shrinking on an annual basis meant that we never had to buy a terminal
> again after we hit our peak in 1984.

Do you know anything about the type/location on the board of this chip?

> Off of a good terminal? I presume that you could find a VT100 from a
> 3rd party vendor. Don't know what they sell for these days.

Hmm.. VT100 keyboard schematics, anyone? :) I'd really like to make this
into a console for my PDP-11.



Christopher Smith, Perl Developer
Amdocs - Champaign, IL

/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
Received on Mon Jan 28 2002 - 13:35:16 GMT

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