older Kinesis classic (KB333) compatibility?

[stapelberg]

I have gotten two questions regarding compatibility with the older kinesis advantage classic (KB333), which predates the KB500 and KB600 models.

The brief answer is that the kinT is currently not compatible with the older classic version.

The long answer is:

Electrically it is compatible, mechanically it is not compatible. The biggest difference are the connectors to the left and right key wells. Newer kinesis revisions use FFC connectors (FFC = flat form factor cables), but in the older revisions, the key well PCBs are directly connected into the controller (no cable).

Unfortunately I don’t know the part number for the required connector. In the humblehacker blog article, the author says they de-soldered the original connector from the original controller. (So if the keyboard is broken and you’re feeling adventurous, that might be an option.)

If you can figure out which part number one needs, you only need to replace it in the kinT controller design. The footprint should be identical or similar.

The only bit that’s worrying me is the physical position on the controller. With the FFC connectors you have a little wiggle room, but I think when connecting the PCBs directly, everything needs to fit much more precisely. Possibly you need to move the connector to the left or right in the kinT controller design, but that might require moving traces as well…

I hope this gives an impression of the kind and amount of work required to make it work

[Sunspark-007]

The connector has been located and confirmed working on a 1995 Kinesis Essential with the new controller. https://www.molex.com/molex/products/part-detail/ffc_fpc_connectors/0520441345

https://www.molex.com/pdm_docs/sd/520441345_sd.pdf

It's listed as obsolete, but there is still inventory left.

[stapelberg]

1995 Kinesis Essential with the new controller

Are you saying you soldered the connector into a kinT controller? Did the kinT design require any changes, or is the footprint and position of the connector compatible?

[Sunspark-007]

I'm not the one who did it, but I sent a message asking if I could see a photo because I want to see if spacing changes were needed or a cable (as well as what was done with the other connectors).. but I think it's drop in compatible because the part number says 13 circuits, and the kinT controller board has 13 circuits. The connector is a right-angle connector, so if the board is the same size as the original and placed in the same location, might just be as simple as that.

[stapelberg]

but I think it's drop in compatible because the part number says 13 circuits, and the kinT controller board has 13 circuits

Unfortunately there are more details to consider than just the number of connectors.

In particular, the vertical distance between the pins of the connector is specified as 2.5mm, whereas the newer FFC connector uses ≈1.6mm. It does not seem to be compatible to me.

The connector is a right-angle connector, so if the board is the same size as the original and placed in the same location, might just be as simple as that.

The kinT board size does not match the kinesis original controller size exactly, and even if it did, the position of the FFC connectors does not necessarily match. Notably, though, even the kinesis original controller changed its size between the KB500 and KB600. It could be that they changed size between the KB333 and KB500 as well (I don’t know).

[aleb]

Below are the pictures of a KB133 and some distances I measured. The board is symmetric from what I can tell.

Looking at the side with four LEDs, the right-side connector has to be moved down (towards the LEDs) 4.5 mm and left (towards the center) 3.7 mm. Similarly for the left-side connector.

Would such a change work for KB500+?

I see it's easy to move the connector in the KiCad PCB editor, but the traces are not moved automatically. Any suggestions how to move them, also considering they are on both sides of the board?

[stapelberg]

Thanks for sharing the details!

Looking at the side with four LEDs, the right-side connector has to be moved down (towards the LEDs) 4.5 mm and left (towards the center) 3.7 mm. Similarly for the left-side connector.

Would such a change work for KB500+?

While it is possible, I don’t think such a change would be ideal:

1. The location of the connectors has been chosen to match the original PCB’s location as close as possible. This ensures our board doesn’t do any worse in terms of putting strain on the flex cables.
2. The further down we move the connectors, the less space you will have between connectors, which makes them really inconvenient to open/close without resorting to tooling and/or damaging your board accidentally.

Given how rare the older Kinesis are, maybe we shouldn’t bother with changing the main kinT design to work for them, and instead just keep a variant around.

I see it's easy to move the connector in the KiCad PCB editor, but the traces are not moved automatically. Any suggestions how to move them, also considering they are on both sides of the board?

If you select the traces and the connector with your mouse (drag open a rectangular selection) and then press m to move, kicad will move both. I think some cutting/re-connecting will be required, but ideally in the part where the traces are straight, so that it’s easy to do.

[aleb]

I did manage to refurbish a KB133. I'll write a blog post with all the details, but for now some pics:

[stapelberg]

Nice work! Looking forward to the blog post

[aleb]

https://aleb.ro/post/2022-09-08-refurbishing-kinesis-KB133/

[stapelberg]

Thanks for sharing this!

[pentuin]

I'm close to giving up. I have a KB500 but it has those rotten stinkin' PCB connectors instead of the flex cable. I installed Millmax sockets on the keywell pcbs but none of the keys in the left keywell work and only 17 keys in the right keywell. I don't think the sockets are the problem, though.

BTW, all of the function keys and the thumb keys work fine (and there are sockets in the thumb keys too, of course. Also the same keys that don't work with the Stapleberg controller also don't work with the original controller.

I've been doing a lot of continuity testing and checking the diodes and most of the key switches work and the passthrough from the anode to the key switch works on all but one of the keys. The continuity from the pcb connector to the keys and test connections are terrible. Almost none of them work. Frankly I'm not sure whether they're supposed to work, but the traces don't look damaged or anything.

It seems to me that except for about 5 keys the problem is entirely in the pcb connector, so I'm wondering if there is anything else I can try.

1. I could get some wrapping wire and bridge the dead pcb connector traces to a trace terminal that still works. (Pardon me, but I don't know the correct nomenclature.)
2. I could remove all of the MillMax sockets and permanently solder the switches, though as I said I doubt that's the problem.
3. I could try manually wiring the keywells, beyond just the bridging. in other words just throw away the pcb and start over.
4. Something else?

BTW, where do you get that pcb editory Aleb is using? What's that?

Here are a few pictures:

[aleb]

You can install KiCad, git clone https://github.com/kinx-project/kint.git and then open kint/kint.kicad_pro in KiCad.

Read my blog post for how I checked the connectivity between the Teensy pins and the paths on the thin semi-rigid PCB.

I see you soldered straight pins into J7 and J2. Will it fit when closing the case?

[pentuin]

I see you soldered straight pins into J7 and J2. Will it fit when closing the case?

Yes. Same height as the pins holding the teensy. Will check out KiCad, thanks!
Update: Actually, come to think of it the sleeves make it a little higher than the teensy pins, but it still fits.

[pentuin]

Where do you get the files for the Kint project, to open in KiCad? Note that my version is from June 2020. Do I need the specific PCB file for that version? (Note: I'm a total novice at this. I do understand electronic circuits to some extent, which I learned at various stages including getting my General Class HAM license.)