Atari 130XE keyboard rebuild: vintage keycaps on modern switches

[+ZuluGula]

15 hours ago, ScreamingAtTheRadio said:

I added a 26 1mm FFC connector that should be compatible with @ZuluGula's adapter.

Just to clarify. This is not my adapter. But i like that idea, and we can replace some of those old connectors with more modern ones, or give people options to choose. 

[ScreamingAtTheRadio]

Here's what the adapters will look like... Let me know in PM if you want one (or more) with your Rev C PCB(s). This was a tight fit, very difficult to route on 2 layers, but they will be very inexpensive to manufacture. They can be made in 0.8mm thickness, which I think should allow for insertion into unmodified Atari keyboard motherboard connectors, and it's less than the 16mm clearance between the MB and the bottom of the keyboard in a standard XE case, but worst case it's easy to replace the connector with some pin headers and fit it horizontally. You can then choose to solder either a surface-mounted FFC connector, pin headers, or a through-hole 2x12 connector. So all options are available, which is nice.

[ScreamingAtTheRadio]

Fabrication and assembly instructions are available:

 

https://github.com/bleroy/3d-junkyard/tree/main/Atari130MX

 

There will be additional photos and videos later.

[venom4728a]

I like the adapter too.  Can I readjust my pcb request?  I would like 4 adapters, 4 alignment plates and 4 keyboard pcbs.   The FFC plug will be too small for me to solder but IDC connector and ribbon cable are easy to do.

 

I finished printing 72 stems, and have swapped the stems in 36 of the kailh keyswitches.  so far 6 of the printed stems have very slight defects that cause them to stick.  I printed an additional 18 stems last night to make up for with defects.   visually they look ok, but there must be a slight imperfection that is causing them to not work correctly.  

 

I like how they keyswitches feel, this will be a nice keyboard.!!

 

Thank You for making this happen!!!

[wildstar87]

Yes, would be interested in a few of the keyboard adapters as well.

[ScreamingAtTheRadio]

On 9/23/2021 at 9:15 AM, wildstar87 said:

Yes, would be interested in a few of the keyboard adapters as well.

Please let me know in PM how many you need of the main PCB, the adapter, and the plate PCB.

 

On 9/23/2021 at 4:58 AM, venom4728a said:

I like the adapter too.  Can I readjust my pcb request?  I would like 4 adapters, 4 alignment plates and 4 keyboard pcbs.   The FFC plug will be too small for me to solder but IDC connector and ribbon cable are easy to do.

Of course. Noted.

 

I finished a first draft of the PCB plate. I'll order all three batches of PCB once I've verified everything fits. Last orders!

[wildstar87]

FYI, I just took a look at my keycaps on my 130XE, they aren't the same as the ones for this project, so there is at least 2 different types of keycaps for the XE keyboards, I wouldn't be surprised if there were a few more, dammit.  I can still use the PCB and Plate.

 

If anyone is interested in the replacement keystems, I have a set on the way that I can't use.

[ScreamingAtTheRadio]

1 minute ago, wildstar87 said:

FYI, I just took a look at my keycaps on my 130XE, they aren't the same as the ones for this project, so there is at least 2 different types of keycaps for the XE keyboards, I wouldn't be surprised if there were a few more, dammit.  I can still use the PCB and Plate.

 

If anyone is interested in the replacement keystems, I have a set on the way that I can't use.

Interesting. Can you share a picture?

 

[wildstar87]

Yeah, here it is, I might be able to do something similar, not sure yet if they would work with the box switches.  Stupid small screws holding the back panel strip way too easily..

 

Also another question, did you just clip off the support posts on the Start/Select keys?  It looks like the plate might have a hole for one of them.

Edited October 2, 2021 by wildstar87

[_The Doctor__]

Yes two different rev.s for key caps and two different mylar sheets versions as well.

[ScreamingAtTheRadio]

46 minutes ago, wildstar87 said:

Yeah, here it is, I might be able to do something similar, not sure yet if they would work with the box switches.  Stupid small screws holding the back panel strip way too easily..

 

Also another question, did you just clip off the support posts on the Start/Select keys?  It looks like the plate might have a hole for one of them.

Thanks, that doesn't look like the box switches would work with that. If you have some openscad skills, you should be able to make a new option for those. I'm interested in covering both revisions if possible. A first approach could be to do a scan of the bottom of the cap (scanners work astonishingly well as measuring devices) plus some caliper measurements. Or, if somebody on the thread has one of those that they would be willing to lend me for a little while...

 

The plate footprint for the functions keys have one hole on the bottom-left for the support, yes:

 

51 minutes ago, _The Doctor__ said:

Yes two different rev.s for key caps and two different mylar sheets versions as well.

I'm assuming the matrix wiring is the same, right? I've never seen a schematic other than the one I used for XE computers.

[_The Doctor__]

matrix always end results as the same, correct.

[wildstar87]

33 minutes ago, ScreamingAtTheRadio said:

Thanks, that doesn't look like the box switches would work with that. If you have some openscad skills, you should be able to make a new option for those. I'm interested in covering both revisions if possible. A first approach could be to do a scan of the bottom of the cap (scanners work astonishingly well as measuring devices) plus some caliper measurements. Or, if somebody on the thread has one of those that they would be willing to lend me for a little while...

 

The plate footprint for the functions keys have one hole on the bottom-left for the support, yes:

 

I'm assuming the matrix wiring is the same, right? I've never seen a schematic other than the one I used for XE computers.

I didn't realize you and I are actually close to each other, assuming your location is accurate.  I'd be willing to work with you on this, if you could help adapt something?

[ScreamingAtTheRadio]

9 minutes ago, wildstar87 said:

I didn't realize you and I are actually close to each other, assuming your location is accurate.  I'd be willing to work with you on this, if you could help adapt something?

Oh wow, yes, Redmond. OK, then that's quite excellent. Let's set-up something so I can take precise measurements and I can send new prototypes your way. Can you reach me via PM so we can exchange contact info?

[venom4728a]

I just popped the keys of all of my 130xe's and I have the same keycaps as Wildstar87.  I have 1 spare keyboard that has the same keycaps that Screamingattheradio has already created a stem for.  I need to stop printing stems for now.

 

[ScreamingAtTheRadio]

All right, so I met with @wildstar87 who kindly lent me his keyboard so I can study it and adapt my design to be compatible with it. It seems completely doable as far as the stems are concerned, but there are other differences that may be additional challenges. So far, we noticed:

1. The different key cap footprint, round instead of square
2. Those keycaps are more cheaply made: the square ones are doubleshot, those are not
3. The function keys have two legs instead of one. That means people who get the Rev C plate ad want to use it with these caps will have to drill 5 new holes into it.
4. The right shift key has stabilizers that the square variant doesn't have. You should be able to just ignore this one, the key's under 2 units wide.
5. The space bar stabilizer is a different shape. Not sure how much of a problem that will be. Worst case, you may have to build a new one from wire.

I'll get started on the round stems.

[ScreamingAtTheRadio]

Today I printed two versions of the stems for the second kind of cap that's around, with the circular footprint. They seem to fit perfectly on the side of the key, but for some reason the ones I printed don't slide properly into the bottom part of the switch and I don't know why yet. It's weird because I didn't change that part, so it may be a fluctuation of the print quality.

Here are some photos. The design is already on GitHub, so if you have a printer you can try it out now.

 

[ScreamingAtTheRadio]

The new boards have arrived. There are some minor issues on which I'll make another update later, but here's a preview of what it all looks like:

[_The Doctor__]

this would be even better with the auxiliary choice to have the extra diagonal function keys continue all the way across. @MEtalGuy66 style.

[ScreamingAtTheRadio]

1 hour ago, _The Doctor__ said:

this would be even better with the auxiliary choice to have the extra diagonal function keys continue all the way across. @MEtalGuy66 style.

Not something I intend on doing on my own 130XE, but if you want to do it on yours, all the files are on GitHub under a friendly license, so it's perfectly doable. There are even a few free GPIO left on the Pi Pico and space for some headers.

[_The Doctor__]

That's not only for the Pi Pico/PC, but for the XE series, as it gives the full 1200XL usage of the Keyboard for use in the XE's...

[ScreamingAtTheRadio]

Just now, _The Doctor__ said:

That's not only for the Pi Pico/PC, but for the XE series, as it gives the full 1200XL usage of the Keyboard for use in the XE's...

True. A lot more can be done.

[venom4728a]

I will print some of the new stems tonight and see what kind of result I get.

Edited October 7, 2021 by venom4728a

[ScreamingAtTheRadio]

7 hours ago, venom4728a said:

I will print some of the new stems tonight and see what kind of result I get.

Great. Very interested to see how it works for you. I realized I used the bottom of a resin bottle so there's that that could account for variations. I'll also try again this week-end with new resin.

 

On the new batch of PCBs, here's some additional info that will interest you if you asked me to send you a sample:

1. The plates are pretty nice. I had them done in aluminum, and I have to say, this may be the cheapest and maybe the proper way to get a milled aluminum plate done. They have a black surface with white silkscreen on top, as you can see in the photos above, and bare aluminum on the bottom. The precision of the milling is not fantastic, if you look closely you'll see plenty of deviations from the design, but they do the job very well and at a price that I doubt can be beaten. Basically, it's the price of a regular PCB, with a supplement  (that you would also have to pay on regular PCBs) for having a lot of drilling to do: it's basically all holes. The cost before taxes and shipping is around $5 a piece, as compared to $70 for a laser-cut steel plate.
2. The holes for the stabilizer wings of the right shift and the control keys are positioned too high. I had to dremel them a little bigger to ensure the keys would move properly. Not a huge deal, but that means you'll have to do some work when you receive your plates. The design on GitHub is already updated for bigger holes, so if you want to have the updated design made, feel free. Rev C.1 should be readable on the silkscreen.
3. I made a mistake and ordered the adapters in 1.6mm instead of 0.6mm or 0.8mm, so they won't fit in the standard Atari connector. If you no longer want them because of that, let me know. I tried mounting them with header pins, and that works, but the clearance is extremely tight if using the IDC connector, especially on Santos' new XE PCBs as there are chips that need to fit underneath. I'd recommend going for the FFC cables instead, in which case there should be plenty of space above (haven't verified that configuration yet as I'm still waiting for my connectors).
4. The Pi Pico can in theory be surface mounted, but then the USB plug is almost unusable unless you have a very thin cable. I've mounted it on headers, and it looks great. Haven't yet tested it on the PC.

That's it for now. Next are connection tests and experimentations with the plates and the circle-shaped type of key cap. The space bar stabilizers are very different.

 

I'll start shipping PCBs this week-end.

[venom4728a]

Well my first attempt to print out the circle stems failed. The build plate was empty. I need to drain my tank and clean it out.  I think the FEP film needs replaced or the resin is bad because my last 2 printing attempts have failed.