NAME  

EC-1

MANUFACTURER  

Heathkit

TYPE  

Professional Computer

ORIGIN  

U.S.A.

YEAR  

1960

KEYBOARD  

Potentiometers and switches

CPU  

No processor but nine DC operational amplifiers

SPEED  

0.5 to 15 repetitive operations per second

RAM  

No memory

TEXT MODES 

Volt-meter

SIZE / WEIGHT 

50,2 (W) x 38,1 (H) x 29,2 (D) cm. / 21 Kg.

POWER SUPPLY 

Built-in 100 Watts main power supply

PRICE  

$400

 

Heathkit EC-1
Heathkit EC-1

From 1950 to 1965, electronic
analogue vacuum-tube computers were
used to design, test and run
civilian and military equipment like
aircraft, ships or rockets. The
first systems were very expensive.
However, components cost (especially
vacuum tubes) was steadily
decreasing.

In 1960, Heath Company launched the
Heathkit EC-1, the first analogue
computer (almost) anyone could afford. It was sold in kit or pre-assembled forms and
was quickly and widely used in industry and universities.

Unlike our modern binary computers, which accept only two values as entry (0 or 1), an
analogue computer represents input and output data's in voltage levels. So, any
positive or negative value could be read directly from the built-in meter. An external
oscilloscope could be also used as a display device, as well as a grapher for printed
results.

In spite of its apparent simplicity, the EC-1 could solve a multitude of complex
mechanical and mathematical problems thanks to nine DC operational amplifiers, three
initial condition power supplies, potentiometers, relay contacts, high precision
resistors and capacitors, and a built-in oscillator for repetitive operation (from 0.1
to 15 operations per second).

The computer was described by Heathkit as "Excellent teaching aid for a course in
computer electronics - Vividly illustrates the electronic analogies to mathematical
problems - Handles problems as complex as fluid flow, damped harmonic motion, and
flight of a projectile in a viscous medium"

Computer problems could be 'programmed' by inserting several patch cords into the
problem-board sockets and thus linking in chain several built-in components together.

The EC-1 and other analogue computers were used until 1965, when first affordable
digital computers became available.

Here is some EC-1 unusual technical features taken from the Heathkit brochure:
* Amplifiers: Open loop gain approximately 1000. Output ±60 volts at 0.7 mA.
* Power supplies: 300 volts at 25 mA electronically regulated; variable from +250 to
+350 volts
* Repetitive operation: Multivibrator cycles a relay at adjustable rates (0.1 to 15
cps)