The Commodore 1551 floppy drive is a rare beauty. Designed for the Commodore 264 series, it borrows the nice black look of the Commodore Plus/4. It connects through the parallel port, unlike the more common 1541 drive, which had a serial connection.

Because of the parallel connection, the 1551 was about 4 times faster than the 1541 by default. (Disk turbos made it even faster, of course.)

The disk drive used regular (single sided, single density) 5 1/4 inch disks. Unfortunately the 1541 and 1551 were not 100% compatible. In the world software releases for the 264 family, this has caused a big mess. Lots of games and demos were 1541 only, and did not work on the 1551 (because of a 1541-specific disk turbo). Strangely enough, the opposite was also true: a few games (made especially German sceners) were 1551 only. This was very unfortunate, and it obviously showed that the coders just didn't care, since it was easy to detect which drive was connected to a machine (and then use a drive specific disk turbo, if necessary).