Sperry UTS-400 Cleaning and Conversion

[digital_matthew]

Hey everyone. My Sperry UTS-400 just arrived from elecplus today (thanks, Cindy!) I want to clean and convert this to use with my PC. I felt like expanding my keyboard restoration skills from the usual Model M/M2s that I've worked on. Also this keyboard just oozes period '80s charm, so I'd like to get it up and running. I've seen some good threads on Key Tronic resto-conversions, but I'm wondering if anyone here has ever done one of these. I've never traced a matrix or wired up a CapSense or anything like that, so I would appreciate some help. Thanks!

[OldIsNew]

Oh that's a nice board! It looks similar to a DEC VT100 Hi Tek board - but is it KeyTronic F&F ? If so, its fairly straight forward to do. Or if its a Hi Tek high profile like the DEC VT100, it's still not hard but takes a different approach. Would be happy to try to help if I can.

[digital_matthew]

Oh that's a nice board! It looks similar to a DEC VT100 Hi Tek board - but is it KeyTronic F&F ? If so, its fairly straight forward to do. Or if its a Hi Tek high profile like the DEC VT100, it's still not hard but takes a different approach. Would be happy to try to help if I can.

Thanks! It's KeyTronic, and I think it's foam and foil. Here's a pic:

[elecplus]

That got there pretty quickly, considering the holidays and all! The other two were purchased by people in the classic computers chat, so they will not be converting them. They have Sperry terminals they want to use them on.

[digital_matthew]

That got there pretty quickly, considering the holidays and all! The other two were purchased by people in the classic computers chat, so they will not be converting them. They have Sperry terminals they want to use them on.

Yeah it was supposed to arrive on January 2nd, so it was a nice surprise to see it on my doorstep yesterday.

So I took the case apart and gave it a bath. I gave the keys a bath as well. If anybody is going to clean these keys in the future, rest assured that denture tablets work great; they won't harm the printed front-legends. When I first saw the faded green sublegends on the tops of the keys I assumed they were printed, but when I looked underneath I was surprised to see that they are actually triple-shot. I'm going to try sanding them to restore their brightness. I guess it's UV damage, or the green plastic doesn't like skin oil. I'm not sure. The front-legends are definitely printed, so I won't be touching those. They look great anyway. I can't believe how well-built this keyboard is, with its metal pan encasing that gorgeous PCB.

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[XMIT]

elecplus has had these for a while. They're under appreciated. A standard capsense controller should work well for them. You may need to replace the foam pads. I think neoprene with a mylar sheet glued to it, punched into circles, makes a fine replacement.

Key Tronic foam and foil gets a bad rap. Sure, the durability isn't there for the original version, but they're still nice capacitive keyboards if you put some work into them.

[OldIsNew]

Yea vintage KeyTronic F&F, nice. I love these boards, though they've gotten a bad rap - I think because of the short stem version which is awful- but I think the tall stem "vintage" boards are really nice. If you want to convert it to use on a Windows PC it's not difficult, but can be tedious. I've converted a number of these boards using the Xwhatsit Model F to USB board, but from what I've seen, the Commonsense board works quite well - I've just never used it.

The first, and most tedious issue IMO, is the fact that the F&F is almost always badly degraded and has to be replaced. It's not hard to do but does take time. Here is one of my links about this:

workshop-f7/westinghouse-w1642-keytroni ... ic#p384536

Next is mapping out the rows and columns so that they can be traced back to their ICs. It's not hard. After unscrewing the front plate from the PCB, just start with one pad on the front of PCB and tap it out with a multimeter set on continuity testing to record which pads are connected to which row/column. Then its just a matter of tracing the rows/columns to the corresponding IC legs, desoldering those ICs and wiring up the capsense controller. These are a few other boards I've done this way:

keyboards-f2/l3-communications-keyboard ... ic#p390190

keyboards-f2/wang-workstation-keyboard- ... ic#p396862

https://geekhack.org/index.php?topic=92 ... msg2505876

workshop-f7/data-general-dasher-and-xwh ... ic#p425864

[digital_matthew]

Thanks for the info, Tim! I'm going to need lots of hand holding on this. My next step is to separate the PCB from the key housing. I'll probably end up doing the foam and foil replacement. I think I have a bunch of anti-static bags around here somewhere...

[digital_matthew]

Okay so I took the PCB apart from the switch plate. Sure enough it looks like the foam is rotting, and some of the capacative material fell off of a few of the pads. Also it looks like the PCB itself has some muck on it. So my questions are: How do I replace the foam and foil? Is there any way to remove the switches from their housing, or do I just dig them out? Can I just clean the PCB with some 91% isopropyl alcohol that I have? Thanks!

[OldIsNew]

There is a clear plastic disk under the foam that snaps into place under clips on the white plastic slider portion of the switch. What I have been doing is using a tooth pick or small jewelers screwdriver to pop the disk/foam/foil sandwich out of the slider. I clean the disks in IPA and reuse them. After cleaning the disks and punching the foam and foil, I've been popping the disks back into the white sliders and gluing first the foam to the disks and then the foil to the foam (NON-conductive side facing the PCB). I've been using Elmer's Craft Bond glue sticks and spreading the glue on the disks and foil with a cut toothpick and this has worked well with all of the boards I've done. It's tedious but works.

As far as cleaning the PCB, I have used 91% IPA and cotton swabs to clean the pads on the PCB and haven't had any problems.

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[Sangdrax]

I redid one of these awhile ago. My favorite Keytronic F&F board and the one I've kept around above all others. Love the layout, love the feel, the keys, the sound and the ping. Everything comes together just right.

If you use an xwhatsit, you'll need the better debounce firmware, but I would recommend the DMA Capsense even if the learning curve is a bit higher for your first project with it (easy as pie after you figure it out the first time). The individual thresholds especially are so helpful on this kind of board.

Here's my old restore topic which does have my matrix traceout in there which should make this a ton easier on you.

viewtopic.php?f=7&t=18562&hilit=sperry+univac

Oh, and if you ever find an old UTS-40 instead of a 400, those are the magnetic valve models. I got one of those too, very cool but unconverted.

[andrewjoy]

I have one but it feel off the shelf and cracked the case so done nothing with it.

I should see what i can do about a case for it.

[digital_matthew]

Thank you so much for these posts, guys. That matrix traceout will be tremendously helpful. I owe you a beer if we ever meet, Sangdrax and Tim

I need to find some foam, and I want to preserve the key feel as much as possible. Does anyone have any recommendations?

[OldIsNew]

Since the original foam on the boards I have was mostly degraded, it's hard to be certain, but from what I can tell, it does seem to be a fairly soft open cell foam. I've been using an open cell polyurethane foam with good results. The keys are, of course, linear and the majority of the force felt when pressing them is from the springs.

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[digital_matthew]

So today I pried the foam disks out of the switch housings, and sure enough the foam was rotted more than I had realized. The key feel was okay when I tried it, so I'm looking forward to typing on it when it's finished. I separated the stiff plastic disks and gave them a wash.

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It looks like I've lost a disk because there are only 112 here, but there are 113 keys. I guess I can just find some thin plastic packaging and punch a new one out of it. No big deal.

I took the opportunity to give the switch plate a thorough scrubbing as well. Now it's all nice and clean.

I also started to clean the traces on the PCB. I used 91% isopropyl and cotton swabs, but it doesn't look like it had much of an effect. Will the traces work if there is a bit of crud on them? I don't want to scrub so hard as to break them, but the alcohol wasn't as effective as I thought it would be. Is there a better method?

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I've ordered the foam that you suggested, Tim, and I'll be picking it up tomorrow. I have an 11mm punch on the way too. I also have some anti-static electronic component bags that I will be using for the capacative material. How do you get the foam disks to be the correct height? Did you build a jig to cut them?

My images are not displaying inline properly. I guess this is a bug that is still being worked out.

[OldIsNew]

It looks like I've lost a disk because there are only 112 here, but there are 113 keys. I guess I can just find some thin plastic packaging and punch a new one out of it. No big deal...

I also started to clean the traces on the PCB. I used 91% isopropyl and cotton swabs, but it doesn't look like it had much of an effect. Will the traces work if there is a bit of crud on them? I don't want to scrub so hard as to break them, but the alcohol wasn't as effective as I thought it would be. Is there a better method?

...How do you get the foam disks to be the correct height? Did you build a jig to cut them?

Those disks are so easy to loose! Like you said not a big deal. I've uses plastic sheets for overhead projectors from an office supply store and they work well.

All of my boards have had discoloration on some of the traces/pads even after cleaning and so far I haven't had any problems - none of my traces, so far, have been corroded all the way though - so I'm not sure worth damaging them with aggressive cleaning.

As far as cutting the foam - some web site, somewhere, mentioned 0.2" as the thickness of the KeyTronic foam disks and this does seem to be about right. I've used this thickness for I think at least seven boards now with good results each time. For cutting the foam disks I went way high tech. I drew two lines 0.2" apart on a piece of 2X4, taped a piece of plastic to the board as a back stop, and cut the foam cylinders with an x-acto knife. I do use calipers to make sure each disk is the right width after cutting:

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[digital_matthew]

So I finally got my foam, and I found the anti-static computer component bags that I knew were lurking around my apartment somewhere. So I decided to cut ~4"X4" squares out of them and laminate them. I ran out of PVA glue, so I went to the hardware store and got some of this interesting DAP brand latex glue. It worked pretty well, but the application was messy, and some got on the front of the blocks. Worried that this would compromise the capacitance of the foil, I tried isopropyl, but that didn't really dissolve it. Fortunately I also have Goo-Gone, which is a citrus based solvent used for removing sticker residue. This worked like a charm.

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Also finally arriving at my doorstep was my 11mm punch. I got to work and punched out a total of 135 foam and foil tubes. Although I will only need 113 for this board, I want to have plenty of spares. Here is the obligatory punch photo:

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Now all that's left to do for this phase is cutting the tubes down to 0.2" and gluing the plastic disks to the back. I've heard people say that they've lubed these switches. How does one go about this? Which lube does one use? Thanks!

[Sangdrax]

Just use a pretty thick lube like superlube and paint it finely with a brush on the three tracks underneath with the slider up, then do the collar on the top side. You should do all this before you put the pads back in, and you can test the feel with the springs and caps installed.