Commodore 1540

The Commodore 1540 (also known as the VIC-1540) was the floppy disk drive for the Commodore VIC-20 microcomputer. It used single-sided, 5.25" floppy disks.

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 under $1,000, although the combination of the Commodore 64 and 1541 would prove more enduring.

Due to a timing conflict with the C64's video chip, the C64 did not work properly with the 1540. The better-known 1541 was mechanically and electronically identical to the 1540 but had a revised ROM that permitted it to work with the C64 by slowing the drive down slightly. It was possible to revert the 1541 into 1540 mode with a software command (OPEN 1,8,15,"UI-":CLOSE 1 in Commodore BASIC) to permit better speed with when used with a VIC-20.

The 1540 is relatively rare because the C64 followed close on the heels of the VIC-20, so the 1540 was quickly discontinued. 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 among those who collect old computers.