.CASS File Extension

A CASS file is a program file used to emulate a cassette-based program created for the Apple II computer. It contains a copy of the data stored on an Apple II cassette, converted for use with Virtual ][, an Apple II emulator. CASS files allow Apple II enthusiasts to run classic, cassette-based programs on modern Macs within Virtual ][.

CASS file open in Virtual ][

Apple released the Apple II computer in 1977. As Apple's first entry into the home computing market, the Apple II represented a huge shift in the company's priorities and focus, culminating in the many consumer market products that Apple produces today. Largely, the Apple II was hailed as a success, resulting in a number of follow-up releases before Apple discontinued the Apple II line in 1993.

The Apple II allowed users to load and run programs in a variety of ways, including via cassette tape. To run cassette-based software, users had to purchase a cassette deck, connect it to their Apple II, and play their cassette in the deck. Then, they had to follow a series of instructions included with the cassette.

Apple II enthusiasts have cataloged and converted a number of cassette-based programs for use with Apple II emulators, so they can relive the PC's glory days. In Virtual ][, the files that contain these converted programs use the CASS extension.

How do I open a CASS file extension?

To open a CASS file in Virtual ][, drag the file to Virtual ]['s cassette player, type LOAD at the Applesoft prompt ("]"), and press Return. When the Applesoft prompt reappears, type RUN and press Return to run the program contained within your CASS file.