"USER FRIENDLY" for July 16, 1994 by Calvin Demmon ("User Friendly" runs each Saturday in the Monterey County Herald, Monterey, Calif. It is also posted each week on the Marshall bulletin board -- phone number listed at bottom.) GARY KILDALL'S WORK LIVES ON The inventor of the C-prompt is dead. When Gary Kildall's death this week at Community Hospital of the Monterey Peninsula was reported, the stories focused, quite properly, on his creation of the CP/M operating system, a major contribution to the development of personal computing. Most PC users no longer use CP/M, but everyone in the DOS-compatible world still sees Kildall's work when DOS is running on the screen. That little A, B, or C with the arrowpoint after it is the way Kildall solved the problem of identifying disk drives on a system. It's the kind of thing you take for granted if you've been using it for years, but if it hadn't been for Kildall, some other display might be on your screen at the operating system level. I met Kildall a couple of times, in the course of interviewing him for The Herald and for a San Francisco Bay area computer magazine for which I wrote a story about his forays into the then-uncharted world of CD-ROM. I liked him very much. He was intelligent, friendly and slyly humorous. And he was, first and foremost, a teacher. He had been a professor of computer science at the Naval Postgraduate School in Monterey when, in 1972, he wrote the first version of CP/M. His professorial habits never left him even after he became one of the most famous members of the personal computing pantheon. If you happened to be standing near a blackboard, Kildall couldn't resist picking up a piece of chalk and sketching out charts and timelines and bell curves to illustrate whatever he was saying. What he had to say was nearly always fascinating. Digital Research, the company that Kildall founded, brought hundreds of talented people to the Monterey area as it expanded. For a time it seemed we might have a Silicon Peninsula here, with Digital Research booming in Pacific Grove and Lifetree Software producing Volkswriter in Monterey. But Lifetree is defunct, and Digital Research has been absorbed into Novell. Digital Research never quite recovered from IBM's anointing of MS-DOS instead of CP/M as the operating system for its personal computers, and none of Digital's other products were ever so important or so universal as CP/M had been. The first full-featured computer I ever owned, an Osborne I, was CP/M-based. I learned my way around on that system, and when I finally switched to a DOS machine, it wasn't all that different. MS-DOS, after all, was basically just a variation of CP/M. DOS featured the A, B and C prompts. Its philosophy and many of its system commands were identical. That was no surprise to Kildall, who told me that when he examined the first version of MS-DOS he found many lines of programming code that he recognized because he had written them himself. Kildall could have sued Microsoft, but IBM promised to offer both PC-DOS (its version of MS-DOS) and CP/ M with its IBM PCs. A lawsuit might have stalled what looked to Kildall like a good marketing opportunity for CP/M. There was a catch, though, and it doomed CP/M: IBM priced PC-DOS at $40 and CP/M at $240. DOS was soon the industry standard, and CP/M faded into obscurity. But CP/M isn't dead. Thursday, when I checked the comp.os.cpm newsgroup on the Usenet network (via the Internet), there were 30 fresh messages relating to CP/M. Most were plaintive cries for help with ancient CP/M-based computers bearing names such as Amstrad, CompuPro, Kaypro and Cromemco. And about half-a-dozen folks had posted messages reporting Kildall's death, including one Silicon Valley type who included (in the kind of copyright violation that is typical in cyberspace) the complete Kildall obituary from the San Jose Mercury. Among the other messages was one titled "Wanted: CP/M Boot Disk." What that guy wanted was what Gary Kildall created 22 years ago, and what we all wanted not long ago -- the key piece of software that made the personal computer revolution not only possible but inevitable.