Found an ADDS Viewpoint Terminal Keyboard

[theycallmestino]

Hi all,

I recently found an Applied Digital Data Systems Viewpoint terminal keyboard. Unfortunately, the foam and foil switches need replacement foam, and the PCB is totally corroded...after a good cleaning, I do not think it will ever work again.

However, the caps are in ok shape and have an amazing feel. and the mounting plate/frame is not rusted too badly. Is there perhaps some way to salvage these parts? The caps are the 2-arm grabber style, is there any hope of them being re-purposed?

[HuBandiT]

Basic armchair thinking (assuming you only have the keyboard and not the terminal too):

* one could design and fabricate just a new foam and foil PCB (including a modern controller); that would still leave the foam replacement issue
* one could adapt the caps to another switch type, and then design and fabricate new keyboard internals (new PCB, controller, switches) into the old housing

Perhaps post some photos.

[seebart]

I'd love to see some pictures of your ADDS Viewpoint Terminal Keyboard!

[theycallmestino]

Nope, I do not have the terminal itself. I could create a custom board, but I do not even know where to start with that...everything that I could build off of that's out there is for modern MX switches.

Here are a few pictures.














capture screen

[HuBandiT]

Looks like it was stored outdoors and not flooded. PCB doesn't look _that_ bad.

You could read up on how it works in the wiki, and read efforts of replicating other capacitive keyboards (e.g. replicating PCBs for IBM Model F). Then based on that you could design your own capacitive PCB (based on the existing one), and adapt one of the capacitive controllers for it.

Ask yourself these questions: How much time/effort do you want to invest in it? Also, how much of an electrical engineer are you or want to be?

[theycallmestino]

It was found in a building that had been abandoned for about 15 years. Luckily it was inside, but doors and windows were open so it was exposed to a few elements (and animals, as you can see in the pic).


I will have to post a more detailed picture of the PCB (after cleaning). basically none of the contacts are shiny anymore, they are rather thin and in pretty rough shape.

There isn't much on the wiki related to this keyboard. Is there someone that takes care of the wiki? I'm happy to provide more pictures and info to get it in there so it's documented.

There's no limit to time or effort, it can be a nice little project. I know a bit about electrical engineering, I am a programmer by trade but studied circuitry and I have repaired several components (pc, radio, monitors, etc). I was thinking of using a spare monitor I have, building a frame in the style of a 70's terminal (something like this http://www.instructables.com/id/70s-Terminal-PC/), mounting this keyboard to it, and using it for my home server.

Googling doesn't provide much help (unless I'm searching for the wrong stuff) as far as building a custom PCB etc. Do you know of any good resources?

I suppose the best place to start is new springs. Is there a preferred online retailer?

[seebart]

This is your keyboard (in cleaner ) theycallmestino:

http://terminals-wiki.org/wiki/index.php/ADDS_Viewpoint

475px-ADDS_Viewpoint_371058667762-1.jpg (91.98 KiB) Viewed 4494 times

The switch looks like Key Tronic foam and foil to me:

wiki/Key_Tronic_foam_and_foil

These are the people who "take care" of the wiki at the moment but Daniel beardsmore is the person to contact.

wiki/Special:ActiveUsers

Good luck with your project!

ADDS_Viewpoint_advertisement_Computerworld_15Jun1981.jpg (574.54 KiB) Viewed 4488 times

[theycallmestino]

Awesome, thank you for the info. They are indeed foam and foil - every single foam piece was deteriorated, so I will have to pick up new ones.

Going to start by sanding down the frame and repainting it. I have the switches sitting in some gentle cleaner at home (the rust from the springs was inside several of the white posts causing them to stick) so those will get cleaned.I have to see how the keys come out,I may need to very gently sand off the stains and discoloration. They are non textured so it shouldn't be that big of a deal.

As for the custom PCB,I quickly found this online http://cubiq.org/build-your-very-own-pc-keyboard so it may not be that bad to do.

[HuBandiT]

Make sure you also read around on here a bit, in the Workshop category:

A) there are often people/threads about custom PCBs with directions as to where to learn circuit design, what circuit design packages to use, and where to have boards fabricated, etc. (One external resource that comes to mind is SparkFun in the US, I think they have extensive tutorials.)

B) There are also other capacitive sensing efforts in the Workshop, where you could find more info, and perhaps get more specific help from people who participate(d) there.

[theycallmestino]

Thanks for the reply, I will have a look. Sorry, I made the classic noob mistake of just posting before delving deep into the information here.

I will probably start a thread in the workshop....I just want to post a pic in here of the PCB later tonight to get a better opinion on it's condition.

[HuBandiT]

Thanks for the reply, I will have a look. Sorry, I made the classic noob mistake of just posting before delving deep into the information here.

Oh, apologies; I did not mean it as scolding - merely just as a "make sure you don't miss out on...". Good luck with the project!

[scottc]

Not to contradict HuBandiT, but designing your own PCB will be incredibly time-consuming and costly for Foam & Foil, which is not a very highly-rated switch mechanism in terms of key feel. People have developed replacement capacitive PCBs and controllers for popular keyboards such as the IBM Model F (which has been very successful), but I can't see new F&F boards getting as much traction.

Another option might be to use as many parts of the keyboard as possible to create a modern custom keyboard with more modern key switches, as HuBandiT suggested. This would probably require modifying the key caps to allow them to fit on modern switches, but would be quite achievable (and there are plenty of resources for doing this).

By the way - your images won't load. You need to put a direct image link into the [img] tag, whereas it looks like you put a link to a webpage with the image on it.

[theycallmestino]

Well if this PCB can be repaired it may be worth while to keep it. I do really like the feel of the keys, I got to play around with it before I disassembled it and it was very satisfying.

I do understand what you are saying, but I do not want to replace most of it and keep just the keys unless I have to - I may as well just buy a whole keyboard at that point! I hope that didn't come across in a condescending manner. The one thing I want to keep together are the caps and switches.

Google is not helping much at all when trying to find information on capacitive rewiring/pcb replacement/other options, so I'm not quite sure what I will do if the PCB is done for. Wiring up a normal keyboard is fine - not sure about a capacitive one.

[theycallmestino]

So here is a close up of the PCB. you can really see the corrosion. This is after a scrub with baking soda:

[snuci]

Baking soda is very abrasive. I wouldn't have used that.

I would suggest a bath of 50% vinegar and 50% water. Dip it in and let it sit for a while. Try soaking for 15 minutes, then 30 minutes, then hourly until you see no improvement. Use a tooth brush or something with nylon bristles to brush off the scale and rust after each soaking but do that while submerged. Rinse with clan water after each cleaning to check your work. I've done this to remove corrosion on PCB boards before. It might take a few hours to even a day but it doesn't look too bad. Soak it up to the components. Soaking the chips is fine (as long as they are cleaned off and dried properly) but I don't know what will happen to the speaker in the corner so try not to immerse that in the water/vinegar solution. Also, you can emerse the springs too. These will not turn out as well but it's worth a shot.

Good luck.

[theycallmestino]

Hmm, so it may be salvageable? I can give it a try and see what happens. The baking soda was on a write up I saw online before I saw this forum.

Unfortunately the springs are way too far gone - over 50% crumbled into nothingness simply by pressing down on a key.

I am having a HELL of a time trying to find replacement springs. Also, I found that the Sol-20 and Apple Lisa use the same switches.

[Mr.Nobody]

I love those vintage Ads and picture of vintage computers you posted, I myself collected some as well. Those green letters on screen somehow are fairly fascinating to me.

[snuci]

Hmm, so it may be salvageable?

Lets see how this goes first. It is hard to determine the level of corrosion from that picture and it still needs a good cleaning because it is still dirty. Sounds like you'll have to find a donor board for the springs though.

[HuBandiT]

Not to contradict HuBandiT, but designing your own PCB will be incredibly time-consuming and costly for Foam & Foil

Not contradicting me at all - it indeed will not be a quick and easy project!

Unfortunately the springs are way too far gone - over 50% crumbled into nothingness simply by pressing down on a key.

I am having a HELL of a time trying to find replacement springs. Also, I found that the Sol-20 and Apple Lisa use the same switches.

Make sure you take measurements on the springs for procurement/re-manufacture. The parameters I suggest are:

• diameter (inner or outer, preferrably both - or one and wire thickness)
• height of uncompressed spring
• operational compression length = height of uncompressed spring minus the height of maximally compressed spring in-situ (that is while the device is assembled and the key is actuated)
• desired force at any of these points or inbetween

Based on these parameters you can go spring shopping, or find a manufacture (a small shop) to re-produce the springs for you.

[theycallmestino]

Thanks for the reply, Hub. Trying to track down a retailer that sells springs of the correct size.

I wan't to document the progress...if a mod does not move this thread to the workshop I will start a new thread there.