News

Jul 11, 2023

Rainer Glaschick's Modular Analog Computer Aims to Bring Back Classic Computing for All

Rainer Glaschick has designed a modular analog computer system designed to offer competition to Anabrid's The Analog Thing — and capable of some surprising flexibility, from addition and integration

Rainer Glaschick has designed a modular analog computer system designed to offer competition to Anabrid's The Analog Thing — and capable of some surprising flexibility, from addition and integration through to triangle and sine wave generation and even Lorenz attractor calculations.

"As classical analog computers are no longer produced, there is a lack of affordable new ones, with the exception of The Analog Thing," Glaschick of the thinking behind the new design on a technology long-since abandoned in favor of digital computation. "The latter, however, sticks to the classical model with all its inconveniences. My new design is close to the classical design, with some small, but for my opinion significant changes."

Chief among those changes is a switch to a modular design, in which strip-like computational components are arranged on breadboards to form a configurable circuit for any given task. "An advanced version without [breadboard] but with digitally controllable options and connection is under test," Glaschick explains.

Other tweaks to the design include easier calibration using digitally-set potentiometers, jumper-based module configuration, a fast-initialization integrator design which supports track-and-hold functionality, a multi-functional adder component which can operate inverted, as a precision rectifier, or comparator, and the ability to easily make additional modules using readily-available 0.1" perfboard.

"The active calculation elements called functors provide an output voltage as a function of the input current (including time)," Glaschick explains of the machine's operation. "The five pins on the [breadboard] are used as follows: 1. voltage input for the factor 1 (i.e. 200kΩ); 2. primary current input (±50µA); 3. & 4. defined per module; 5. voltage output. Pins 3 and 4 may be analog in- or outputs, or digital signals; the latter sinking 1mA to ground (from positive supply) if true."

From adder, integrator, multiplier, and factor connectors it's possible to build up circuits capable of a range of tasks. Glaschick has demonstrated the system configured as a triangle wave generator, a sine wave generator, a Lorenz attractor calculator, a simulator of Udo Knorr's Fahrdiagraph, and even a functional Moon Lander instrumentation system.

More information, including schematics for each of the components and the resulting systems, is available on Glaschick's project page.