Electronic Associates Inc. Model 680 Scientific Computing
System
UvA Computer Museum catalogue nr 93.56
Our EAI 680 has been part of a hybrid system; unfortunately the
digital part has not survived. Nevertheless the 680 is a complete
analog system equipped with
- 120 analog modules including integrators, summer/amplifiers,
limiters, function generators, multipliers, comparators and a/d
convertors. These units are accessible through the removable patch
panel (right).
- A control & logic panel (upper part of the patch panel)
containing various gates, clocks, pulse generators, relays and bcd
counters.
- 100 servo-controllable coefficient potentiometers, plus a
number of manually adjustable units on the front panel (left).
- A keyboard for entering coefficients and for general
control.
- Lighted pushbuttons for reading and defining the state of the
logical units.
- A digital voltmeter with a large decimal display (bottom
left).
The results of the computations can be displayed on a plotter or on
a large screen oscilloscope (not shown; we don't have the original
EAI units).
Our 680 machine, dating from 1968, is fully functional. The picture below shows the machine while solving the differential equation of a damped pendulum.