deskthority

We lost Mr. Beardsmore's interest a few months back. He seems to have left unceremoniously. Come back sir.

I have a board with these, and on a few switches the yellow insulating tape/gasket material has fallen out. It seems to be about the thickness of scotch tape and has the effect of slightly dampening the sound. Anybody know of a source for this material, or a source for replacement leaf spring ...

Hi gang, does anyone know of or have any kind of protocol data for Data General keyboard<-->terminal connection? I've got a leaf spring 3rd gen board with a db-9 connector and it's using 6 lines -- 2 serial in/out pins, and 4 others called KBIRQ, KBC RESET, CLK COM and SCLK.

I'm going by some info ...

vintage bakelite potentiometer!

From what board were the switches harvested? Also from the Focus board?

Rub it in our face why don't ya.

In taking apart this Micro-Switch SC keyboard I found a strange dry filmy substance that had been slathered all over the membrane.

My guess is that this was placed there intentionally and is not a spill of a beverage or something like that. This is based on the fact that it appears to be "evened ...

One of the best parts of this is the badass supermarket scale.

I have an Amkey board with these switches. It's an XT-layout board with no identifiable model number. Definitely foam and foil. Very smooth keyfeel though, and the case is all metal. I purged all the switches out of mine and am reusing the very solid case, plate and backplate to make another board ...

Yeah they are kind of hit and miss. Just like alps the condition seems to be key. I have 2, one is in pretty good shape and is usable, the other has the same problems you mention. Lube on the switches does not seem to help, but a drop of lube where each stabilizer wire contacts the plate does help ...

FWIW I had the same problem with my H412. It would work with both the inline (Belkin) PS/2 converter and the blue cube but be pretty much unusable due to dropped keystrokes and repeat key weirdness. It does work fine on PS/2 directly. You could try one of those "breakout" cables to get around the PS ...

It seems that Maxi switch is different than Maxi-Switch (later Honeywell) in Freeport, IL.

Thanks for the suggestions, greatly appreciated.

The SC switch appears to be for the special handling of the 'numlock' key. There is a custom keypad on the left with changeable legend keys, and a numeric keypad on the right.

Good to hear that it's possible for these switches to be good, even if ...

I have this old board, 1984-ish, that has (what I believe to be) Micro-Switch ST discrete rubber domes .

https://preview.ibb.co/d6jSzQ/2017_09_22_19_38_46.jpg

In general this is not a great switch. They are very mushy and have hardly any tactility.

Some of the domes are completely squashed and ...

Hi gang, I have an NEC 'blue oval' board I picked up a few months back and just got around to using it yesterday. I think somebody used the crap out of it, because it types fine, but is very scratchy and rough on the keyfeel. Also if you hit the key even slightly off axis it will bind on the way ...

Thanks for testing it responding back. It's great to have this keyboard working without having to butcher it!

At the moment, this is a Z-150 only build that probably does not work with other boards.

Wiring is the same, but make sure you have the reset line wired to pin B7 (also same as Soarer's converter).

You can use an existing Soarer's converter but only if it is based on the Teensy 2.0, I can post ...

OK guys, here's a .hex file for the Teensy 2.0 that works perfectly for the Zenith Z-150 black label. I added a few fixes and it finally works great without dropping any keystrokes. Please test it on your own Z-150 and post feedback here.

Yeah it's a decent board. I guess my point was that the black label Z-150 is an XT keyboard that does not speak XT. Using a model F as the "standard", the data line (opposite polarity), number of bits (9 vs. 10), and reset line are all different. I'm going to fiddle around with the TMK xt_usb module ...

I hooked up this board to a logic analyzer and it clearly speaks a different protocol. Here's an example.

This is a "normal" XT keystroke with the DATA line held normally low, and CLK normally high. When ready to send a code, 10 CLK falling edges are sent: 2 start bits, 8 data bits, for a total of ...

thanks, am trying that, BTW, is it acceptable to connect the shell ground connector to ground on the Teensy or should it be left not connected?

Hey, glad you guys are checking this out. I just built a Soarer's converter for my black label Z-150:
- no pullup resistors
- v1.12 firmware
- Teensy 2.0
- Reset line connected

It does work, but drops some keystrokes at a fast speed. Any clues on how to fix...

Thanks for the help. The source of the problem, I think, was the single screw in the PCB, wasn't in all the way. I also squeezed the tab a little more to make sure the plates were well fitted. Seems to be working now. Pic attached is the screw that wasn't tightened all the way.

Hi all. I have a Model F XT that I recently took apart and cleaned, also repainted the barrel plate. Some great references and tutorials out there. I did not replace the foam as it seemed to be in pretty good shape.

It seems that the keyboard is quite sensitive to vibration. For example if I poke ...