The Aleste contains a disk controller, so no external disc interface is required. The floppy connector is the same as the "Drive B Connector" on CPC, the only difference is that outputs select signals for two drives (A and B).
The 'official' Aleste drive is 3.5"", 720K, 80 tracks. It does also contain the power supply for the computer (which must be connected via whatever separate cable).
=== Magic Sound Expansion Board ===