This document copyright Herbert R. Johnson 2008. Updated Aug 15 2008.
Contact and email information can be found in this notice.
The Home page for all my Digital Research CP/M Web pages and information is at this link. The first CP/M systems and many others were S-100 bus based systems. To learn more about S-100check my S-100 home page.
Jonathan Titus has degrees in chemistry from the 1960's and 70's including PhD. work at Virginia Polytechnic Institute and State University. While there, he was part of the "Blackburg Group" with Dr. Chris Titus and David G. Larsen. Together they wrote tutorial articles on TTL digital design in electronic trade publications of the early 1970's. These were later published in book form as the "Bugbook" series. These articles and books taught and influenced many in the digital electronics industry as well as hobbyists in the 1970's.
In the early 70's, Jon worked with the early Intel microprocessors, and eventually developed a simple-to-build microcomputer around the Intel 8008. He developed the design into a construction article and in July 1974, Radio-Electronics published a front-page construction article on building his 8008 microcomputer called the Mark-8. Beyond the fact that the Mark-8 was a very early microprocessor-based computer kit, this article's appearance is credited as encouraging Radio-Electronics's magazine rival, Popular Electronics, to find a similar microcomputer construction project. What they found, and published a cover story about in January 1975, was the MITS Altair 8800.
Jon did not produce his products and kits in quantity. The project was intended by him to "show other hobbyists and experimenters they could have their own computer". In a 1999 interview by Doug Salot of the "Blinkenlights" Web site, he was quoted as follows: "I found my old tax forms and looked at the royalty amounts I received from Radio Electronics and from Techniques, the [New Jersey] company that produced the printed-circuit boards. It looks like Radio-Electronics sold about 7500 of the $5 [construction] booklets, which is far more that I would have remembered. About 400 sets of [$50] boards were sold."
Jon, or Jon and his Blacksburg colleagues, designed a number of related microcomputer projects. A "Mark 80" was designed and a book written to support it. A similar 8080 design was licensed to E&L Instruments as the MMD-1 or Mini Micro Designer.
Jon's career, from then forward into the 21st century, was and is in the electronics trade journals as a trade journal editor and author, and as a digital consultant. He continued to be an author or co-author of many books on digital design. And, he continues to be considerate to newcomers to what was called "microcomputing", even as he writes about the latest microprocessor development kits and products.
An article relevant to CP/M history was Jon's September 15 2001 editorial on IBM-PC history on its 20th year. Check his article at this link to the Test & Measurement World's Web site.
In late June 2008, I stumbled across a Web site on Jonathan Titus and his Mark-8 8008 computer. It's apparently a 2007 Web site for student participants in the IEEE Computer Society student competition, at Florida Gulf Coast University. Jon Titus gave them an interview about his Mark-8 development; and they have archived an earlier interview he gave on the subject. A few quotes above are exerpted from material and interview from this site.
The competition was monitored by Dr. Alan Clements, a computing professor and computer historian at the University of Teesside in the UK. He has some notes on microcomputer history on his Web site, and a book on microcomputing history in progress as of 2008.
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Copyright © 2008 Herb Johnson