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March 11, 2021 Archives
Thursday, March 11, 2021
CONTINUITY: Building a Vacuum Tube Computer: Four-Bit Instruction Register
This project's goal is to build a vacuum tube implementation of the Motorola MC14500B Industrial Control Unit, a CMOS microcontroller with a one bit data path which was manufactured between 1977 and 1995 and frequently used to replace electromagnetic relay controllers in industrial equipment.
The electrical design is interesting, using a B+ voltage of just 24 volts, which is great for safety and avoiding unwanted excitement, but limits the fan-out of gates.
Posted at
15:51
THE HAPPENING WORLD: Space Factories—Building 3D Printed Spacecraft in Space
Posted at
15:06
CONTINUITY: Slow Food—72-Hour Beef Wellington
Posted at
14:42
CONTEXT: Why Real Explosions Don’t Look like Movie Explosions
Ahhhh—the old det cord and petrol trick…
Posted at
13:41
CONTINUITY: From the 1960s—A Seven-Segment Neon Nixie Tube Emulator
This is amazing: a direct replacement for Nixie tubes that provides a seven-segment flat display using light pipes, neon bulb illumination, and a diode logic decode matrix to convert digit signals to segment encoding. The drive voltage is sufficiently high that the voltage drop in the diodes isn't a problem.
Posted at
13:32
TRACKING WITH CLOSEUPS: Descending Perseverance Rover Images its Heat Shield Impacting Mars
Posted at
13:06