Had a little play, using some SMT buttons i’m using in another project. These switches aren’t quite correct for this project – I need ‘square’ button-y bits and preferably ones with a small sticky-outy or inny bit that’ll let it capture a keycap straight.
Assuming the A500 Mini is 1/2 scale, like the C64Mini was then it’s looking good for keyboardification.
This keyboard is about 225mm x 56mm which is about 1/2 the size of the original membrane – I ‘think’ – based losely on numbers from here which says
Full sized Amiga is about 470mm wide by 325 deep.
Half that gives about 235 x 162. take a bit off the 235 for the case thickness bit – gives 225. then height is set roughly by the number of keys ‘down’ and eyeballing the various membranes i’ve found!
However – I don’t know the internal space availability of the A500 yet – so plan going forward for now is to prototype as a 2 part PCB.
One design part of the C64 Mini keyboard kit I never really liked is the standalone Arduino Pro Micro mounted on the rear due to being no space. Adding it to the main PCB was also out of the question as the separate components would have been at least double that of a ‘cheap’ arduino.
I’ll keep a 31 way (ish) connector on the main keyboard part, so it essentially acts like a traditional Amiga Keyboard. I’ll then have a ‘special’ RP2040 based PCB that converts the Amiga matrix into USB for the A500.