Olivetti Logos 262 PD desk calculator - keyboard hookup

The keyboard of the Logos 262 PD is connected to the main board with a flat cable, all soldered. The way it was built is not convenient for attaching lots of wires in parallel and routing them elsewhere. So I opted for a more intrusive approach: unsolder the flat cable on the main PCB and install a row of 1" female headers.

Now I can plug the Arduino adapter board directly on top of the main PCB, or re-seat the original cable into it. Last but not least I left room on the adapter board to solder the original cable, making it in parallel to Arduino signals.

No more keyboard soldered. But wrong headers!

Notice that I used the wrong pin headers: these are optimal as IC sockets, but they do not accept male headers! I had to hack a connector, extract its thin pins and use them on the adapter board. I will keep this in mind for the next conversion!