Franklin hobby computer

Dublin Core

Title

Franklin hobby computer

Subject

computer hardware: microcomputer

Description

In 1974, a Torontonian electronics hobbyist Howard Franklin designed and constructed a fully functional microcomputer using a MIL MF8008 8-bit microprocessor. His computer was possibly the earliest example of a Canadian hobby microcomputer and is one of the earliest hobby microcomputers ever designed.


Howard Franklin reconnecting the boards of his MIL MF8008-based hobby microcomputer which he constructed in 1974. Photograph by Zbigniew Stachniak, 2004.

Franklin's computer specification:
  • CPU - MIL MF8008, 8-bit
  • RAM - 16 KB (8 x MIL MF2102)
  • I/O device - Teletype Model 15
  • Software - monitor (including teletype I/O)

The introduction of the first commercial microprocessors to the market in the early 1970s prompted several companies and individuals to design small, inexpensive, general-purpose computers around these novel semiconductor devices. When the first such computers (commonly referred to as microcomputers) began to appear between 1973 and 1975, they caught attention of electronics hobbyists. Their enthusiasm for the ‘computers of their own’ gave birth to a strong microcomputer hobby movement that played a pivotal role in the social acceptance of personal computing. These were the computer hobbyists who challenged the traditional boundaries of computing and its social status, and helped making personal computer use and ownership a reality. Canada was not an exception. Several Canadian electronics hobbyists were members of the first amateur computer club -- the Amateur Computer Society formed by Stephen B. Gray in 1966.

Howard Franklin was one of many Canadian electronics enthusiasts reading popular hobby electronics magazines, most notably Radio Electronics and Popular Electronics, and working on construction projects published in them (building radios, amplifiers, etc.)

During his high school days he had an opportunity to learn about computers and their programming thanks to educational initiatives such as the University of Waterloo computer days, the Toronto Board of Education summer computer programs, and the North York board of Education special computer clubs. In 1973, Franklin learned about the Intel 8008 microprocessor and decided to build his own computer using its clone--the MF 8008--manufactured by Microsystems International Ltd. (MIL) of Montreal. There was sufficient technical literature on the 8008 which included schematic diagrams of rudimentary microcomputers based on this microprocessor: the Intel SIM8-01 and the MIL MOD-8. The study of published circuitry was the starting point for Franklin's computer project. The most innovative contribution to the design was the front panel circuitry that allowed data and short programs to be keyed-in directly into his computer using the switches of the front panel.

Franklin began the design of his computer in early 1974. His first set of schematic diagrams was ready on March 14th but it was revised on May 6th. The computer was operational by the end of that year and modified further through 1975. In 2004, Franklin recollected that the design and construction process was a great learning experience. He found debugging of the design time consuming but not frustrating. "I would sit there and patiently debug wire by wire the design -- oh this is interesting because you have never done anything of that scale before. So debugging took a while." Although Franklin designed his computer completely by himself, he built it with the assistance of some of his colleagues. "Here is the design, would you like to help building it, programming it?" recollected Franklin in a 2004 interview.

Acquiring all the components for Franklin's project wasn't an easy task. They were expensive not only for him but for many electronics hobbyists. According to Franklin, two companies that (indirectly) contributed to "solving" the computer components supply problem and inevitably supported the growth of the Canadian computer hobby movement were MIL and Consolidated Computer Inc. (CCI) of Ottawa. Components that were out of specs were finding their way into the hobbyists' hands through the backdoor. Some of the circuit boards used by Franklin came from CCI, the MF8008 CPU and memory from MIL. Franklin suspected that "The management most likely knew about this, did not worry about things that were going on at the backdoor; they knew who the chips were going to, they were not going onto the grey commercial market, they were going out to students who were building things as hobbyists."

Franklin's computer was assembled using wire wrap technique. Electronic components mounted on printed circuit boards were interconnected by wires, with the connections made by wrapping several turns of uninsulated sections of the wire around a component lead or a socket pin. Wire wrap tools and chip sockets were available via mail order or from numerous electronics stores that offered inexpensive wire wrap equipment to the hobbyists. This made the completion of Franklin's project feasible as soldering of all the connections would require the production of PCBs and would make debugging much more complicated.

The primary I/O device interfaced to Franklin's computer was the Teletype Model 15 made by the Teletype Corporation (introduced by the company in 1930). In the 1960s, computer industry was switching from early teletype models, such as the 15, to newer models including the Teletype Models 33 and 35. Franklin recalled that in the early 1970s, "the junkyards were full of the 15s and were happily given away rather than accumulated in storage. The hobbyists became quite skilled in making the 15s operational and quickly learned how to interface them with their hobby computers."

Howard Franklin graduated from the Electrical Engineering program at the University of Toronto. One of his most successful projects was a microcomputer-based voting system for the Borough of North York completed in 1977 and in operation for several years. (The museum has full documentation of the system.) Franklin was also an active member of the Toronto Region Association of Computer Enthusiasts  (TRACE)-- arguably the earliest Canadian computer hobby organization. He was writing a column for the TRACE Newsletter on computer hardware.

Creator

Howard Franklin

Date

1974-1975

Rights

York University Computer Museum

Files

Franklin8008C.jpg

Citation

Howard Franklin, “Franklin hobby computer,” York University Computer Museum Canada, accessed July 5, 2022, https://museum.eecs.yorku.ca/items/show/290.

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