CP/M and Digital Research Inc. (DRI) Web pages

Many software and hardware companies of the 1980's and beyond, began as one or two-person companies offering a CP/M-compatible program, or a 8080 or Z80-based hardware product or system. CP/M was the dominant operating system for the 8080 and Z80 based systems of the microcomputer market in the mid-1970's through well into the 1980's. Created by Dr. Gary Kildall before 1975 and sold quietly in that year as CP/M version 1.3 for $70 per disk, it became known as IMSAI's first diskette operating system IMDOS in 1976. Gary Kildall and his wife formed Digital Research Inc. to sell and support the product. A popular release was CP/M 1.4 in 1978, and later as CP/M 2.0 and 2.2 in 1979. It was popular because it was cheap and non-proprietary, and because it included all the software tools and information necessary to move it to any hardware platform with a terminal and a floppy diskette controller. Proprietary or competing Z80/8080 operating systems of the time were often program-compatible with CP/M. Non-Z80 systems sometimes had a "Z80 card" in order to run CP/M.

The Intel 8086 and 8088 processor, the latter used in the IBM PC, became available in the late 1970's. The origins of MS-DOS was an 8086-based OS written to be functionally and operationally compatible with CP/M 2.2 for the 8080. That OS was bought by Microsoft and sold to IBM as PC-DOS for their 1981 IBM PC. Throughout the 1980's, Digital Research produced CP/M-86 and a series of other operating systems for IBM-PC compatibles, as well as advanced OS's for 8080-based systems, and products for systems with 68000-compatible processors. Digital Research Inc. was bought by Novell in 1991 for $120 million. DRI OS products are still sold today (2008) by DRDOS Inc. Dr. Kildall died in 1994.

If you copy or use the above paragraphs, please cite Herb Johnson as author and link to this Web page. - Herb Johnson

Origins of this Web site

As of year 2007, Dr. Gary Kildall's operating system called CP/M is at least 31 years old. That is based on a 1976 announcement and discussion of CP/M as a product in a new but popular computer magazine called "Dr. Dobb's Journal". But development and early sales of CP/M date a year earlier. Dr. Kildall and his company, Digital Research Inc., sold that OS and subsequent operating systems and development tools into the 1990's, until the company was acquired by a series of other companies. As of 2007 the current owners of DRI licenses including CP/M is "DR-DOS Inc.". Kildall died in 1994.

My primary computing interests are in S-100 systems. Up until 2004, my Web site covered early Digital Research CP/M products, because S-100 systems used them. Then I had the following experiences, which I wrote about at the times they occurred.

"There was a discussion in May 2004 in newsgroup comp.os.cpm, on realtime OS and CP/M computers. It happens that I have a collection of DRI documents and software which I've listed on my S-100 site. As that list and my site have been around for several years, this page is often found by Google searches on DRI. In the comp.os.cpm discussion, someone groused that a bit of my DRI info misled him. So I've added some researched OS descriptions to the page and asked the discussion for summary information or links to same." - end quote.

Then, in 2006, I got mad about all the press that year for "the 25th anniversary of the IBM-PC" and "25 most important personal computers", "computer software", etc. etc. - all of which considered the IBM PC and MS-DOS as much more important that those computers and software before 1981. Hrummph! So I gathered some more information...