This sits between an ASCII keyboard and the Apple II to 'change' the ASCII values to whatever values you want.

I originally built this to fix a specific keyboard with a damaged controller, but I feel I've designed it in such a way that one could use it to add alternate layouts or modes to any keyboard. You could change to the DVORAK layout, or add a CAPS mode for example.

Each of the jumpers tie the inputs of the inverter to +5v, resulting in LOW signal at address lines A7, A8, A9, A10.

Modifier keys when pressed are expected to GND a line that is tied to +5v with a resistor when the key is not pressed.

This wire coming from your modifier control line gets connected to the second pin of the jumper instead of having a jumper there.

Hopefully, that is clear. This worked perfectly for me as designed, but as with any of these open and free projects, you are on your own.

All the best!