It doesn’t happen often that we report on new vacuum tube based computer designs. Today however, we’re pleased to introduce to you the Fast Reliable Electronic Digital Dot Computer, or Fred.Computer ...

Building a paper tape reader by itself isn’t super complicated: you need a source of light, some photoreceptors behind the tape to register the presence of holes and some way to pull the tape through ...

Linear, small-signal AC models can be useful in the analysis and design of vacuum-tube-based circuits. Under large-signal conditions, nonlinear models are typically required. Almost 120 years ago, ...

The K2-W vacuum-tube op amp has an LTspice-simulated open loop gain of 27,000. The modeled K2-W input impedance is >100 MΩ. The LTspice modeled result shows 1.00 nA of input current. Early SPICE ...