Recreating A Numpad For The ADM-3A

[Evan] by now experienced a performing ADM-3A (a dumb terminal from 1976) but was commencing to eye the components hungrily. He had only found the numpad on Wikipedia and in the handbook. So when he found some authentic stackpole numpads on a surplus sale, he grabbed them and converted them to be ADM-3A compatible.

On the lookout at the schematic for the ADM-3A, [Evan] figured out that the numpad was parallel to the keyboard matrix, not adjacent. This meant that urgent a 5 on the keyboard was electrically equal to urgent a five on the keyboard. So keeping shift though punching on the numpad qualified prospects to some sudden characters for individuals of us employed to extra contemporary keyboards. Given that [Evan] only required to make one particular or two of these, he soldered wires immediately to change contacts in the matrix that the ADM-3A expects. A 3d printed housing, some rubber toes, and a ribbon cable later on, it was completed. When it seems to be slightly distinct from the unique, the vibe is appropriate, and provided that it is a stackpole swap, it has the same truly feel. With the spare numpads, he established a alternative PCB that operates QMK and connects to a more present day laptop through USB-C. The files for the 3d printed housing are also up on GitHub, together with the PCBs and QMK configuration data files.

If you are interested in what extra you can do with an ADM-3A, why not hook it up to a Raspberry Pi?