Ad in PC Magazine, June–July 1982, p. 164. This may have been Norton's first display advertisement. He ran a classified ad in the April–May issue, p. 136.
DOS 1.1 reads all sectors on side 1 first, incrementing the track number before the head number, while DOS 2.0 increments the head number before the track number. Norton, Peter (July 1983). "The Dark Side of PC-DOS 2.0". PC Magazine.
Review: Visi On Applications Manager, InfoWorld, March 12, 1984. "(Don't be confused by the manual, which states that 256K RAM is all that is necessary. The system requirements listed on the Visi On box specify 512K, and you will need it.)"
Digital Research (1984): Concurrent CP/M ships early in response to team effort. Digital Dialogue - Employee Newsletter of Digital Research Inc., Volume 3, Number 1, p. 1 ([5]).
US trademark, registration #1036693, serial #73064349. Word mark: FLIPPY, First use: July 1974, Filing date: Sept. 29, 1975, Registration date: March 30, 1976. United States Patent and Trademark Office (uspto.gov) Trademark Electronic Search System (TESS)
Caldera. Caldera releases OpenDOS kernel source to the Internet - Distribution of OpenDOS kernel unprecedented in Computer Industry. Press announcement as of 1997-04-30 ([30][usurped]).
Brooks, Vernon C. "History of DOS". PC DOS Retro. Archived from the original on 2020-02-21. Retrieved 2014-02-13.
