The Commodore 2031 and Commodore 4031 are single-unit 5¼" floppy disk drives for

Commodore International Commodore International (other names include Commodore International Limited) was an American home computer and electronics manufacturer founded by Jack Tramiel. Commodore International (CI), along with its subsidiary Commodore Business Mac ...

computers. They use a similar steel case form to the Commodore 9060/9090 hard disk drives, and use the parallel

IEEE-488 IEEE 488 is a short-range digital communications 8-bit parallel multi-master interface bus specification developed by Hewlett-Packard as HP-IB (Hewlett-Packard Interface Bus). It subsequently became the subject of several standards, and is ...

interface common to Commodore PET/CBM computers. Essentially, both models are a single-drive version of the Commodore 2040/4040 units. The Commodore 2031LP is functionally the same as the 2031, but used the lower-profile tan case of the second version of the

Commodore 1540 The Commodore 1540 (also known as the VIC-1540) introduced in 1982 is the companion floppy disk drive for the VIC-20 home computer. It uses single-sided 5¼" floppy disks, on which it stores roughly of data utilizing Commodore's GCR data enco ...

floppy disk drive intended for home computer use. These drive models use a single-density, single-side floppy data storage format similar to that used by the

Commodore 1541 The Commodore 1541 (also known as the CBM 1541 and VIC-1541) is a floppy disk drive which was made by Commodore International for the Commodore 64 (C64), Commodore's most popular home computer. The best-known floppy disk drive for the C64, th ...

drives, but with a slightly different data marker indicating which model originally formatted the disk. The low-level disk format is similar enough to allow reading between models, but different enough that one series of drive models cannot reliably write to disks formatted with one of the other model series. A difference of one extra 'header' byte is what causes this write incompatibility.

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