1541 floppy drive
The 1541 was a single sided 5 1/4" floppy disk for the Commodore 64. It utilized a serial connection to the host computer, and was better known for being SLOW. On reset, the 1541 would crash the head to 'find' the home sector making this a very LOUD drive, giving the impression that it was broken.
The drive housed a 6502 CPU, memory and ROM set that made the 1541 almost a full computer onto itself, which also kept its cost up very high.
The 1541 was also used in the portable business version of the Commodore 64, the Commodore SX-64. A slow floppy drive turned out to not be what the corporate business world wanted.