The Commodore 1540 (also known as the VIC-1540) is the companion

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

drive for the

VIC-20 The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit entry level home computer that was sold by Commodore International, Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commod ...

home computer Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a s ...

. It was introduced in 1982. It uses single-sided 5¼" floppy disks, on which it stores roughly of data utilizing Commodore's

GCR GCR (or GCRS) may refer to: Science * Galactic cosmic ray, a cosmic ray from outside the Solar System * Geocentric Celestial Reference System, a coordinate system for near-Earth objects like satellites * Geological Conservation Review, a procedu ...

data encoding scheme. Because of the low price of both the VIC-20 and the 1540, this combination was the first computer with a disk drive to be offered on the US market for less than although the combination of the

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit computing, 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in ...

and

1541 __NOTOC__ Year 1541 ( MDXLI) was a common year starting on Saturday of the Julian calendar. Events January–March * January 4 – Leonardo Cattaneo della Volta is elected to a two-year term as the new Doge of the Republic o ...

would prove more enduring. The 1540 is an "intelligent peripheral" in that it has its own

MOS Technology 6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit computing, 8-bit microprocessor that was desi ...

CPU (just like its VIC-20 host) and the resident Commodore DOS on board in

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

– contrary to almost all other home computer systems of the time, where the

DOS DOS (, ) is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible syste ...

was loaded from a boot floppy and was executed on the computer's CPU. Due to a timing conflict with the C64's video chip, the C64 doesn't work properly with the 1540. The better-known 1541 is mechanically and nearly electronically identical to the 1540 but has a revised ROM that permits it to work with the C64 by slowing the drive down slightly. However, it is possible to revert the 1541 into 1540 mode with a

Commodore BASIC Commodore BASIC, also known as PET BASIC or CBM-BASIC, is the Dialect (computing), dialect of the BASIC programming language used in Commodore International's 8-bit home computer line, stretching from the Commodore PET, PET (1977) to the Commodore ...

software command (OPEN 15,8,15, "UI-" : CLOSE 15) to permit better speed when used with a VIC-20. The 1540 is relatively rare. While cheaper than most other drives of the day, it was more expensive than the VIC-20 computer itself, and the disk media was also still relatively pricey. Also, the relatively small memory of the VIC meant that the faster program loading times of the drive did not gain more than a few seconds compared to tape media. Thirdly, almost all commercial software for the VIC-20 was sold on cartridge or cassette tape media, giving low incentive to buy a floppy drive. The C64 followed close on the heels of the VIC-20, quickly discontinuing the 1540. Most 1540s still in existence were modified with a 1541 ROM so it would work with a C64. Unmodified 1540s are now considered collector's items. The launch price in Germany was (approximate The American version is named and the German version

References

VIC-20 CBM floppy disk drives {{compu-storage-stub