From CPCWiki - THE Amstrad CPC encyclopedia!
ADDING A SIDE SWITCH TO A 3.5 INCH DRIVE FOR THE CPC.
Adding a side switch to your 3.5 inch external disc drive will give you full use of the drives capacity and is quite an easy job but you will need to have access to a wide range of tools. All you will need to buy is a miniature single pole double throw toggle switch (cost 50 pence to a pound). Firstly decide where you are going to fit the switch remembering that it must not foul existing components and that you need room to solder on the wires, then mark the spot. Next remove the drive plus anything else from the case, take your hole cutter or large drill bit and make your hole, clean up the edges and remove all the metal or plastic cuttings/filings from the drive case. The next job is to cut the 34 way data ribbon cable, place it on a flat surface (a piece of waste wood) and using a razor blade or very sharp knife slice through either side of the pin 32 wire (see above illustration) for about 2 inches, then lift this wire and cut it in half and solder on two lengths of wire. Now reassemble all the components, solder on the wires as per the illustration above -- job done. You would have already decided what software you are going to use with this new set up, so boot up and test it out.
