Repairing the power supply from a 1969 analog computer #VintageComputing @kenshirriff
Ken Shirriff posts about his adventures in repairing a 1969 Model 240 analog computer from Simulators Inc.
We recently started restoring a vintage analog computer. Unlike a digital computer that represents numbers with discrete binary values, an analog computer performs computations using physical, continuously changeable values such as voltages. Since the accuracy of the results depends on the accuracy of these voltages, a precision power supply is critical in an analog computer. This blog post discusses how this computer’s power supply works, and how we fixed a problem with it. This is the second post in the series; the first post discussed the precision op amps in the computer.
Analog computers used to be popular for fast scientific computation, especially differential equations, but pretty much died out in the 1970s as digital computers became more powerful. They were typically programmed by plugging cables into a patch panel, yielding a spaghetti-like tangle of wires. In the photo above, the colorful patch panel is in the middle. Above the patch panel, 18 potentiometers set voltage levels to input different parameters. A smaller patch panel for the digital logic is in the upper right.
See the entire post here – Ken always does an excellent job of explaining the troubleshooting process and provides excellent pictures.
Adafruit has had paid day off for voting for our team for years, if you need help getting that going for your organization, let us know – we can share how and why we did this as well as the good results. Here are some resources for voting by mail, voting in person, and some NY resources for our NY based teams as well. If there are additional resources to add, please let us know – adafruit.com/vote
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.