The computer system consisted of two units - EC362 and EC372 - that could be used independently or linked together to provide a complete system for computer education.
To enable the input of relatively long programs and the output of computed results, an ASR33 Teletypewriter with 8-hole punched paper tape input and output was connected to the two linked units. In addition, a textual output was printed on an 8 inch (200 mm) wide paper roll.
Unit EC362 was the Arithmetic Unit and unit EC372 was the Core Store and Control Unit. Both units had the same physical size (about 1m high x 600mm wide x 600 mm deep) and the large size allowed the units to be used in a classroom, either singly or jointly, in a demonstration mode.
Each unit had a removable, push button, input console connected to its parent unit via a long connector. This feature allowed input and control of the units at the same time as allowing students a full view of the mimic diagrams on the front of the units.
The lamps on the mimic diagrams could be arranged in groups of either three or four yellow and white lenses. This feature provided the opportunity to use OCTAL coding or HEXADECIMAL coding without having to make wiring changes. The use of different groupings of the coloured push button key tops provided the same facility for input coding.
Behind each of the removable consoles was a set of switches that were used to insert predetermined fault conditions to allow the teaching of faultfinding procedures.
Special thanks to Brian Townsend who gave us this venerable machine.
My secondary school classroom (in Crowborough, E. Sussex) had an Arithmetic Unit from the ABACUS Educational Computer that was kindly donated to the school by Feedback. This was in 1971 and the school was Crowborough Beacon Comprehensive.
I had a lot of fun playing with the machine, either single stepping though binary arithmetic or playing a game of "yellow lights vs. white lights," where the objective was to take turns doing a computation that would increase the number of your chosen color at the expense of the opponent''s color.
I like to tell my children that I''m so old, my first computer was an ABACUS!
Wednesday 16th November 2011
What is an abacus and how is it related to the computer?
Sunday 19th September 2010
There was a version of the ABACUS at the C&W Engineering College, Porthcurno, Cornwall on which I cut my teeth in the programming field. I am interested in getting a circuit diagram for it if its available.
Friday 6th February 2004
Martin MacLeavy (Kingston Jamaica)
ABACUS Educational Computer
BUILT IN LANGUAGE
36 Input keys and 4 Function keys
250 Hz. (4 ms per instruction except Multiply & Divide
1 KB of ferrite core storage organised as 512 off 2-byte (16 bit)
Hard copy and punched paper tape output via ASR33 Teletype