[WTT] IBM M4 keypads for your ??

[Yasu0]

I probably only need one of these. Maybe less. But it was a package deal and I wanted to feel the feels.

[mrprofessor]

PMed

[Muirium]

Sharkey describes them here, in the section on M4 numpads:

https://sharktastica.co.uk/articles/m4_story

Apparently they contain no controller of their own? I see those cables in your photo are a mixture of types. The ones without PS/2 look like what he describes.

[sharktastica]

Sharkey describes them here, in the section on M4 numpads:

https://sharktastica.co.uk/articles/m4_story

Apparently they contain no controller of their own?

Correct. FWIW, I now have a more descriptive page on the M4/M4-1 numpad. But TLDR: an M4/M4-1 keyboard is needed as a host for the numpad. The given cable serves only to transfer its membrane traces directly to the host keyboard. You could create your own controller for one, though. Thankfully, the membrane connectors are the same family (Triomate 2.54mm) as larger Model Ms, so you could adapt any number of other gen 1-3 Model M controller projects.

I see those cables in your photo are a mixture of types. The ones without PS/2 look like what he describes.

The top-left keypad is a Model M3. Ie, the numeric keypad option for the IBM PS/2 L40SX laptop. Its internal assembly is basically the same as the M4's, but it has an AT-compatible controller. Whilst I'm at it, I should point out that whilst it has a mini-DIN connector, it's not a standard PS/2 pinout. It's wired as if it's a mouse PS/2 plug (for its passthrough port), with keyboard CLOCK and DATA assigned to the typically unused pins on a 6-pin mini-DIN. Again, you could create a converter that takes this into account, but no off-the-shelf PS/2 converter will work for these (except for its mouse passthrough).

[VelonicV]

PMd