[vcf-midatlantic] Museum report: terminals

[Herb Johnson]

>Evan said: 

> Regarding the terminals: now that we pretty know * what * we have, the
> next step is to organize it all. Right now it's all in one aisle, but 
> only a little organized by cart/shelf. There are some obscure terminals 
> that we probably don't need, and not enough of what we probably do need. 
> This job will be hard work due to the weight of TTYs and stuff.

Well, Evan asked me to come in on Sunday, to review the terminals and 
inventory them. That's because of my experience in the era of the 1970's 
and 80's. I was a minicomputer and mainframe site manager, and I was a 
technical student user at various universities; later I was a digital 
engineer. I also repair terminals. I'll walk though what I saw, and post 
a summary here to inform the people Evan is asking for help. I'll send 
Evan a more detailed report, but he has the list and location-of 
information I compiled Sunday.

I did a quick survey (two hours), focused on CRT-based terminals and 
gave the list to Evan. Only warehoused terminals, not ones on display. 
Mostly there's DEC terminals. A dozen VR-201's (most with "moldy" CRTs). 
VR-201's are CRT "heads" which have a cabled keyboard, and often were 
used with DEC desktop computers. Also a few DEC VT-100 or VT-180; the 
180's may have a microcomputer. A few DEC 200 or 400 series terminals.

A few each, of ADM-3A,  Heath H19 (Zenith Z19), a Perkin-Elmer model, an 
IBM model, a few other brand/models. There's a small number of one-each 
of ASCII based commodity terminals - this is what Evan called "obscure" 
I think. Hazeltine brand, ADDS, and so on. Evan has the list, he can 
provide details. Some of these have "moldy CRTs" too.

Many terminals used detatched keyboards. There's boxes of keyboards, 
which I did not survey; so I don't know if there's enough or too many! 
And there's a few mechanical or printing terminals, which I did not 
survey but noted. I didn't cover monitors - I'll explain why that 
matters to terminals.

I saw many "moldy" CRT's - that's when the front of the CRT has a 
transparent cover that's separating from the glass. Repair means 
replacing the CRT, which can take most of an hour depending. CRT's are 
available for tens of dollars for common types, some CRTs can be swapped 
around from microcomputer monitors, even old TV's. A number of tech 
volunteers are familiar with these repairs.

Evan said "There are some obscure terminals that we probably don't 
need". I disagree, for several reasons. If they work, they are useful; 
if they don't the CRTs may be useful. It's a matter of history - lots of 
little companies made terminals, it's not all IBM, DEC, HP. Here's my 
experience, Evan - computer rooms in the era used lots of kinds of 
terminals. Also: to provide public visitors with a terminal they can 
bang on. And, terminals won't be EASIER to get in the future.

But, it's ALSO true, there were computer-rooms with one kind of 
terminal. The HP, Perkin Elmer, IBM, DEC terminals I saw may go with 
specific minicomputers in the collection. The museum may need more of 
those. Only DEC VR201's seem to be in any quantity.

Evan's focus on Sunday, was to identify and organize. I'm looking a 
little further ahead, to repair and potential uses. Now, with a list in 
hand, Evan can ask others to look over specific terminals for repair, to 
identify monitors as "CRT donors", to solicit CRT's for replacement. And 
to start looking to match minicomputers with terminals for display and 
use. And, to allocate terminals for various purposes, and to tell people 
what terminals we have or don't have. I'm describing my general results 
here in the list, so people with terminals or monitors, or skills, are 
better informed and can offer specific help or items.

Herb Johnson


-- 
Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net
preserve, recover, restore 1970's computing
email: hjohnson AT retrotechnology DOT com
or try later herbjohnson AT retrotechnology DOT info