Switch collection Cherry M51-0131
||Burroughs cruciform post
|Of which broken
The part number is confirmed, as these were sourced from a labelled Cherry box. These are Burroughs-specific custom switches with a non-standard keystem. They take the same keycaps as the M94A-1GBR switches found across Bulgaria.
Although numerically they are placed within M5 series, these are M7 parts. The Cherry drawing for these shows a Style B switch (and seems to give the date of Style B’s introduction), but notes that the part number used to be M51-0129. It is not clear whether M51-0131 represents a revision to the original design (e.g. move from Style A to B) or whether M51-0131 indicates the redesigned version built from German tooling under Series M7.