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 Early trainer computers from 1965 and 1972 
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Joined: Wed Jan 09, 2013 6:54 pm
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Found these... the 1965 BI-TRAN SIX and the 1972 COM-TRAN TEN, large-format demonstration/training computers:


(Photo from this article)


(Image by Putdowntheinternet here)

It seems Fabri-Tek originally made these machines, possibly by licensing designs from other people, and in due course set up a subsidiary Digiac for this part of their business. The military was still using these systems for training in 1983, or at least still citing the accompanying documentation. There was also a COM-TRAN EIGHT in 1968, but I can't find much on that.

Some quotes from my posts elsewhere:

Sister Keller, educator and pioneer in computer science, the first woman to earn a Ph.D. in computer science in the US. Seen here in 1965 with the six-bit teaching computer, the Bi-Tran Six from Fabri-Tek. The computer has 30 opcodes and addresses 128 words of core memory. The transistor-based logic boards are easily accessed for diagnosis of deliberate faults. No dangerous voltages exposed! It seems the US Navy used these machines for training, into the 70s. The booklet suggests a 45 hour course.
Some materials to digest: ... 70628_0207 ... 71010_0075
Some anecdotes about using the machines in this thread: ... i-Tran-Six

An eight-bit trainer, the COM-TRAN TEN by Digiac, from 1972, is for teaching how to code, I think, not how to hook up a 'scope and fix broken logic, as the BI-TRAN SIX was. It had 1k addressable memory (implemented as core.) There's a photo and a huge PDF on bitsavers:

The training manual, from 1981, is here:
where we learn there are 44 opcodes, including multiply and divide and memory access time was 8usec. It's an 8 bit machine with a 10 bit address bus and 1k of core memory. There's a hex keypad - we've moved up from octal, and from toggle switches. Looks like instructions are two bytes, with a 10 bit literal and the possibility of using the 8 bit index register.

Via the discussion here (sign up and log in to see attachments) ... 10-Trainer

Some images here from Stephen Frey: ... -Six/page5
"The computer was stored in a barn for a long time and has needed a lot of cleaning. The third picture is of the core memory unit. The main display can be lifted on sliders for access to changing the light bulbs, raising the display for viewing and seeing the back side of the main circuit board. There are two views where you can see the main circuit board. Mostly TTL 7400 series I.C.s. I hope to get it working again. Give that about 50% chance at this point but that confidence is getting higher as I get into it more."
"I recently became the owner of a FABRI-TEK COM-TRAN TEN. I am trying to get it working again. I downloaded the pdf manual with KDA3032 but would like to find circuit diagrams and I.C. layouts for more of the main circuit board. Probably the rest of KDA3034. Many of the I.C.s don't have their labels anymore. The one I have is I believe an early one. I.C.s have date codes of 1968 through 1971 and the serial number is CT-0002-C2. Probably from 1972. It uses the Model 422 Magnetic Core memory, Serial Number 68373. It was the property of Cincinnati Technical College back in that time frame. I have a lot of computers that I use for STEM education including a Relay Based Machine I designed and built. I think the COM-TRAN would add a lot to my demos."

Notably this barn machine is labelled as FABRI-TEK, so must predate the spin-out of Digiac.

This US Navy training manual from 1983 references the 1972 manuals for the COM-TRAN TEN!

Hints of a predecessor in 1968:
"Fabri-Tek Reverses Its Earnings Trend Earnings of $79,759 by Fabri-Tek, Inc., Minneapolis, in the first quarter of the current year signal the reversal of two years of loss operations. Sales were $4,189,622 down from $5,427,968 in the previous year
The educational products division has recently expanded its line through the acquisition of the rights to Com-Tran Eight ..."
"The Com-Tran Eight, a computer system for college-level instruction, comes with a complete set of instructional materials. The portable unit offers an expandable computer system with hands-on capability. Fabri-Tek, Inc."
"COM-TRAN EIGHT ... a powerful third generation digital computer system designed specially for educational purposes. Large display board shows the class each system operation after instruction. Teletype input/output plus optional standard peripherals. Conversational FORTRAN plus special SIMPLE. (Simplified Instruction Machine and Programming Language for Education)"
- google books search, snippet view results

Thu Aug 30, 2018 6:04 pm
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