Drive Compatibility

Drive compatibility

The CPC disk drive connector follows the original Shugart standard, and has a "Ready" signal in pins 33-34 (pins 1-2 in CPC connector as in the manual). A logical low means the drive is ready, "Has disk". Currently all modern PC 3.5" drives follow a newer standard, which has a "Disk change"-signal in pins 33-34. A logical low means "No disk" so these drives will not work with the CPC, and it will display a "Disc Missing" message. A workaround to this is to jumper pins 33-34 in the cable, forcing the drive to think there is a disk inside.

Some older drives can be configured with jumpers to provide the "Ready" -signal, so you don't need the jumper in the cable. This is usually marked by RY/DC (Ready/Disk change).

All modern PC drives are also hardwired to be the drive 1 (A:-drive in the PC world). This means the drive will act as B-drive in CPC. Some drives have the option to change this behavior (jumpers DS1 and DS0 or D1 and D0) which allows you to use the drive as A-drive. Or you can jumper pins 13-14 in the cable to force the drive to be DS0. This will halt CPC at the start though so do it after starting.

There can also be a jumper for the disk density. This should be set to LOW or LD so the drive is forced to low density mode. This way you don't have to tape over the hole in the disk.

Working

• Panasonic JU-256, HD drive, needs jumper at 33-34 to force "Ready"

Non-working

• TEAC FD235HF-217U, (reason? Was not because of the "Disk change"-signal)
• TEAC FD235HF-240U, as above

Particular models of interest

• TEAC FD-235F or HF, any except the two above - These drives are usually low-density ones and have the jumpers to provide automatic "Ready"-signal.
• TEAC FD-235HF-3240-U - This drive has a 4x7 matrix of jumpers and can be configured in almost any way possible. Very good for various projects.

Useful links

3.5" floppy FAQ - UnixPC FAQ about 3,5" disk drives.

Amiga Floppy Drive Compatibility List - A lot of this applies to CPC also.

Floppy Diskdrive connector pinout - Both Shugart and the newer pinout explained