Mod Mmm ortho PCB by Ming-Gih Lam – turn your IBM Model M into a hotswap MX ortho keyboard.
KBD.news Published June 7, 2024
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As already mentioned earlier in April, Ming-Gih Lam aka dcpedit published the Mod Mmm, a PCB designed to replace all internal components of an IBM Model M keyboard. You keep the curved steel backplate, mount these PCBs, and get a versatile MX-compatible Model M.
Today, I wanted show off a new version of my IBM Model-M mod which uses an ortholinear layout. It uses the same daughterboard as the standard Mod Mmm PCB, but requires a different firmware build – dj_edit.
The Ortholinear Edition, shared recently, is a separate PCB that supports an ortholinear layout. Otherwise it's almost identical to the standard one and utilizes the same daughterboard. Features: 1u or 2u spacebars, 1u or 1.5u vertical center keys.
One of the more challenging parts of the build was dealing with the mounting screw on the PCB. Due to the non-standard layout, the screws overlapped with the switch footprints. With screw heads that were 0.9mm thick, the author decided to use a 1mm thin foam spacer with holes for the screws to elevate the switches above them. This worked well, although it raised the keycaps by 1mm, creating a slightly larger gap at the bottom of the alpha keys compared to the others. As a result, the switches aren't completely seated against the PCB, but this didn't affect their stability since the switch plate provided support.