The original TV Typewriter was difficult to assemble and some of the ICs were going out of production so Southwest Technical Products decided to redesign the kit. The hobbyist had to acquire the rest of the components on their own. Southwest Technical Products got their start selling sets of bare circuit boards for $27 and the eight major integrated circuits for $49.50. The design was soon improved to use a full featured keyboard encoder IC. The first version used simple RTL ICs to decode the key matrix. Popular Electronics (April 1974) featured a complete keyboard kit designed by Don Lancaster and available from Southwest Technical Products for $39.50. The plans for this encoder were also included in the TV Typewriter booklet Don Lancaster's prototype TV Typewriter which is now on display at the Computer History Museum has a surplus keyboard with an ASCII encoder circuit that was published in the February 1974 issue of Radio-Electronics. Most hobbyists chose to use a surplus keyboard and modified it to produce ASCII codes. This project involved hand crafting 55 key-switches including fabricating the springs for each key-switch. The unit on the September cover shows a keyboard project Don Lancaster did in the February 1973 issue. The TV Typewriter project and kit did not include a keyboard. Surplus keyboards were available to hobbyists but they often produced codes other than ASCII, such as Baudot or EBCDIC. In 1973, new keyboards were only available to computer and terminal manufacturers. Today keyboards are readily available and inexpensive, and they have a standard interface. Keyboards ĭon Lancaster's $40 Keyboard kit produced by SWTPC. A serial interface board designed by Roger Smith was published in the February 1975 issue of Radio Electronics. ![]() Don Lancaster wrote about these in the September 1975 issue of BYTE magazine and his TV Typewriter Cookbook. The original TV Typewriter design did not include a serial interface, modem connection, or offline data storage on cassette tape. The April 1975 issue of the Micro-8 Newsletter has 6 pages of user modifications and interface designs to connect the TV Typewriter to Mark-8 or SCELBI computers. But many finished the project and some even connected it to their Intel 8008 based computers. The compact design and complex circuitry made the TV Typewriter a challenging project for hobbyists. Both of the notices were included in later printings of the booklet. The December issue had a page of corrections for the TV Typewriter booklet. Don Lancaster also answered a series of reader questions and gave ideas for additional functions and uses for the TV Typewriter. They also listed electronics parts sources for the difficult to find components. In the November issue, the editors apologized for the delays in shipping the TV Typewriter booklets to the thousands of readers that ordered them. With professional terminals costing over $1,000 this $120 kit looked like a bargain. Instead, they were flooded by requests and eventually sent out 10,000 copies. Given its limited functionality, they initially estimated that the magazine would sell about 20 copies of the plans for $20 each. In addition to the six-page article, they also offered to ship out a larger 16-page version with complete layout plans for a mail-in fee of $2. ![]() The article appeared in the September 1973 issue. On-screen text was generated by the Signetics 2513, one of the first character generator integrated circuits. Much of the circuitry was involved in timing the output of the analog generator with the memory, which had to be shifted bit-at-a-time to the output. The video project gave Don the inspiration for his most influential project, a low cost video terminal known as the TV Typewriter.īuilt in the era before widespread availability of low-cost microprocessors or solid-state computer memory, the system used small-scale integration TTL digital logic and shift register memory. Don was also a prolific author of hobbyist projects for Popular Electronics and Radio-Electronics magazines. Don Lancaster was an engineer at Goodyear Aerospace designing a high resolution video display for the military.
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