If Babbage had started the computer revolution early, we might have seen a mouse like the one [Peter Balch] created. He started with the guts from a USB wheeled mouse and some gears from an old clock movement. In addition to the big wheels to capture X and Y movement, the mouse buttons look like the keys from an old typewriter.
We were afraid the project would require advanced wood or metal working capability, but the bottom of the mouse is made from paper mache. The top and sides are cut from tinplate. Of course, the paint job is everything.
The electronics part is pretty simple, just hacking a normal mouse (although it is getting harder to find USB mice with mechanical encoders). However, we wondered if it would have been as simple to use an optical wireless mouse. That would leave the wheels just for show, but honestly, most people aren’t going to know if the wheels are useful or just ornamental, anyway.
If you don’t feel like gutting a mouse, but you still want USB, you could use an Arduino or similar board that can simulate a mouse. We’ve seen quite a few of those in the past. Now all you need is a matching keyboard.
The ZX81 had a single port: a PCB edge connector at its rear that exposed all the Z80 processor’s lines. It was notorious for unreliability, as the tiniest vibration when a peripheral was connected would crash the machine. Maplin’s expansion system featured a backplane with a series of edge connector sockets, and cards with bare PCB edge connectors. Back in the 1980s it was easy to find edge connectors of the right size with the appropriate key installed, but not these days. [Alan] had to make one himself for his build.
