Gary Kildall’s Design of Knowledge Retrieval Systems for PC

Gary Kildall who created the CP/M operating system discusses how he almost accidentally created it, and also a range of topics related to how he coded and how he taught programmers at the Naval PostGraduate School.

The story he shares of CP/M (which stands for “Control Program for Micros” is fascinating in that CP/M was originally just a little fragment of a very large project Kildall was working on with XPL, a language for mainframe computers created by Bill McKeeman. Kildall was developing a similar language for micro computers called PL/M. CP/M was just an interface he needed for the language to communicate to a disk drive so he wrote it. He remarked it wasn’t clear to him CP/M would be a hit, but he was sure that the newly invented “floppy disk drive” was going to be a hit.

At the time of the interview for the book Programmers at Work, Kildall thought that PCs evolving into digital information tools at home and the office would propel the spread of PCs which were in the doldrums at the time. It was the optical disk drives and CD Roms that would enable that. He envisioned a world of “knowledge systems” and “expert systems” on the PC. Interestingly, the idea of interconnectivity and the internet was absent from their visions. Below is one sketch of his early designs for a flexible approach to his “KRS” management software.

Gary Kildall KRS Sketch in Programmers at Work

Gary Kildall KRS Sketch in Programmers at Work

You can read a lot more in his interview and the excerpts featured on this site. He was a remarkable architect of software and a real visionary of his era.