VDM-1

In September 1973, the cover article of Radio Electronics magazine was Don Lancaster's "Build a TV Typewriter", which allows users to type characters on a keyboard and have them appear on a conventional television.

He had designed the Pennywhistle modem to address the need for remote access at a price under $100, but the terminal that they hooked it up to still cost $1500.

[4] Felsenstein sold the design document to local hobbyists, and wrote an article on it in the People's Computer Company in early 1974.

[8] In April 1975, Bob Marsh and Gary Ingram formed Processor Technology, initially to sell expansion cards for the Altair.

Marsh approached Felsenstein with the idea of modifying the Tom Swift design to work with the Altair, which had been released that January.

[9] As soon as the prototype was ready, Steve Dompier began porting Star Trek to it, replacing its serial output with a more game-like display to produce Trek-80.

He first approached Don Lancaster, who created the original TV Typewriter, and introduced him to Ed Roberts of MITS, the creator of the Altair.

Marsh again turned to Felsenstein to design it, and as soon as they began discussing it, it was clear the best solution was a complete computer system.

[13] It also added a split-screen feature that allowed the upper and lower sections to be scrolled independently, and place the split at any line.

[14] By the summer of 1979, Felsenstein had a partially assembled version and took it to the Javits Convention Center in New York City to show it to the Processor Technology people.

[10] The front side of the board was crammed with components, including eight 91L02A 1,024 bit static RAMs, to the point that there was not enough room left for the required electrical traces.

[10] The board generates 16 lines of 64 characters[17] on a monitor or a conventional television that is slightly modified[10] to bypass the radio frequency section.