Floppy Disk Drive
The keyboard cable uses RJ12 connectors that have 6 poles, but only 4 middle are used for connections (so called 6P4C). Obviously 6P6C connectors will work too. It is necessary to connect only middle 4 poles, one to one.
Atari STM1 mouse, but with different internals to the one I have with 1040STE.