electronics and model rockets. Roberts augmented his Air Force salary with an off-duty company, Reliance Engineering. Mims, Roberts and two other co-workers decided they could design and sell model rocket electronics kits to hobbyists. The December 1969 issue of Model Rocketry carried a press release written by Mims announcing that Reliance Engineering had formed a subsidiary company, Micro Instrumentation and Telemetry Systems. They designed and built the telemetry modules in their homes and garages but they were only able to sell a few hundred units. Mims' background in the new technology of light-emitting diodes allowed him to sell a feature story to Popular Electronics magazine. Their monthly circulation was 400,000 readers compared to Model Rocketry circulation of 15,000. The five-page article would give an overview of the device physics and typical applications; it would be featured on the November 1970 cover. Mims asked the editors if they also wanted a project story and they agreed. Ed Roberts and Mims developed an LED communicator that would transmit voice on an infrared beam of light to a receiver hundreds of feet away. Readers could buy a kit of parts to build the Opticom LED Communicator from MITS for $15. MITS sold just over hundred kits. MITS was not making money on the kits and magazine articles paid $400. Mims was out of the Air Force and wanted to pursue a career as a technology writer. Roberts bought out his original partners and focused the company on emerging market of electronic calculators. The January 1975 cover of Popular Electronics featured Roberts' Altair 8800 computer. Roberts asked Mims to write the Altair 8800 user’s manual in return for an assembled Altair, which Mims donated to the Smithsonian Institution’s National Museum of American History together with many original MITS documents and his high school language translating analog computer, in 1987. Author Mims wrote technical books on semiconductor lasers and light-emitting diodes. He coauthored a book on electronic calculators with his friend, Ed Roberts in 1974. Les Solomon, the Technical Editor of Popular Electronics, liked to meet the magazine's authors. When he was on vacation in 1970, he visited Forrest Mims and Ed Roberts in New Mexico. Solomon gave them advice on selling project kits such as the "Opticom LED Communicator" but Mims was really interested in becoming a full-time writer. Solomon explained the magazine publishing business and helped Mims get articles placed in Popular Electronics.