Since a disk drive is by nature a moving part, it is inevitable that it will fail someday. The vast majority of Amiga computers out there are least a decade old (some are nearly 20 years old), and so many users have had the misfortune of their disk drives dying on them. Replacing them is difficult because while Amiga disk drives are for the most part electrically compatible with those used in the Wintels of today, there are slight but vital differences in terms of both signals and pinout.

The problem stems mainly from the fact that Commodore used low-density drives throughout the Amiga line up until the Amiga 4000 and 3000T. (After that they made things even worse by switching to custom-made high-density drives that spun at half the speed of a normal high-density floppy drive.) In contrast, low-density drives were quickly phased out of use in the IBM world sometime around the mid-1980s and can be found on only the oldest of machines. The aim of this guide is to provide information on which disk drives will work or can be made to work in an Amiga.

If properly configured, some drives listed will work right away, and some will work with modifications. Most others cannot be configured at all. Drives that can't be reconfigured can be made to sort of work with a cable hack, but the “diskchange” signal will probably not work right (at least, it never worked for me). As a result, the Amiga will not be able to tell whether or not the drive has a disk inside. It is not possible to swap disks in games or start up an Amiga 1000 past the “insert Workbench” screen with this trick. Drives that have been modified or reconfigured sometimes suffer from a missing or different “ready” signal- this can cause problems with certain pieces of software that access the disk drive directly.

If you don't feel like modifying an existing floppy drive or can't find one that can be reconfigured, there are a few alternatives. Individual Computers offers an adapter board called the Kylwalda, which can be used to make almost any modern Wintel disk drive fully Amiga compatible. Eyetech also used to sell something called the EZ-DF0, which does something similar.

The following chart should help in figuring out which model of floppy drive might work best with your Amiga. Some work, some need modifications in order to completely work, and the rest will only partially work with the cable hack.

3.5 Drives:

NOTE: All drives listed will only work with Amigas as 880K or 720K drives unless specifically noted.

Advice for unknown drives: if there's config switches or jumpers (sometimes you have to open the cover to get to them), experiment with every combination and see if that makes the drive work any better. If there aren't any, it's probably only going to work with the cable hack(which is not a practical solution) or an adapter board(which is costly).

See also: http://www.pitsch.de/stuff/amiga/floppy.htm