VT131 needs keyboard help

From: Jerome Fine <jhfine_at_idirect.com>
Date: Tue Jan 29 08:52:49 2002

>Christopher Smith wrote:

> Another weekend project of mine has been working on a VT131
> terminal. The terminal seems to work fine when receiving data.
>
> The terminal always powers up with a "4" in the corner
> (keyboard error?). Typing characters on the keyboard will give
> no response from either the terminal, or the system to which
> it's connected. The lights flash (all at once), and the speaker
> beeps when power is applied to the terminal. No lights are ever
> activated afterwards, though.
>
> Having taken apart the keyboard, it does have an empty socket for
> a DIP. Anyone know what this is?
>
> Is it possible that this is a "lookalike" keyboard? Did DEC make
> different models for different VT100 terminals -- were they
> compatible? If this is an authentic DEC keyboard, will it be
> marked as such somewhere? If so, how?
>
> The key layout _looks_ like VT100, but...
>
> The reason I'm asking about the brand is that there was another
> terminal at the junk yard, completely trashed, which looked like
> a VT100, but had a completely different branding. I forget the
> brand right off, but I'm afraid I may have picked up the keyboard
> for the dead terminal, and that it may not be compatible at all.
>
> Failing a way to positively identify the keyboard, are there any
> common modes of failure along these lines?
>
> Also, I'm guessing at this point that the terminal is in good shape.
> Does anyone know where to get a keyboard?
>
> Chris
>
> Christopher Smith, Perl Developer
> Amdocs - Champaign, IL

Jerome Fine replies:

As far as I know, ALL VT100 style keyboards are identical. As are
all LK201 keyboards for a VT220/VT320, etc. If you can find an
old dead VT100 style terminal, normally the keyboards last much
longer than the monitor portion - at least my PILE of old keyboards
is my experience.

However, there are many components inside the monitor that also
must work correctly which are concerned with receiving characters
from the keyboard and sending those characters to the computer
(or whatever is at the end of the RS232 cable). And although they
rarely are non-functional (in most cases when a terminal goes bad
I can still send characters to the computer), I guess it can happen.

Suggestion: Get another keyboard or at least test your keyboard
in another VT100 style terminal.

OTHER KEYBOARDS from compatible VT100 terminals WILL
PROBABLY CAUSE DAMAGE to the VT131. I recommend
against doing that. If you are not sure - normally compatible terminals
are clearly marked as non-DEC, don't experiment.

Hope this helps!
Received on Tue Jan 29 2002 - 08:52:49 GMT