Retrofitting a CPC 664 with a 3.5" drive (ParaDOS recommended for full capacity)

[OCT]

Thought I'd document this old mod of mine while I have the photos available, as it will hopefully be of use to others running out of 3" drives as well.

First we'll have to make way for the slightly larger 3.5" drive by summoning the powers of Dremel (no such traces of the procedure will be visible from the outside):

With the original 3" drive's side bracket removed and some insulating tape applied to the power switch, the internal Shugart bus cable (just about long enough) needs to be converted from 26 to 34 pins by leaving a little gap on the new connector, while the power cord will have to become a little longer and get its pinout flipped over in the process - in what has certainly been a death-trap to many a replacement drive, Amstrad used a colour-coding opposite to the PC industry standard! The misspelling galore is also all theirs.

With a few strategically placed clamps, drillings and screws, the "new" drive (jumpered to the same Drive Select as its 3" predecessor, and rewired -in a procedure that is different for every incarnation even among TEAC drives- to handle the READY pin in a way compliant with the requirements of 8- and 16-bit tech) is firmly held in place.

The finished result (after screwing the ground wire to the 3.5" frame and plugging the back connectors into the drive now held by the hood, in a tight space of just about an inch) from front...

...(for safer transportation, and to allow fitting an HxC emulator's buttons into it if need be, the lower part had not been glued back in place just yet), and rear:

Standard disclaimer: YMMV, at your own risk, don't try this at home. But heck, this 664, it still is one beautiful CPC.