Email the author: glenk AT internode.on.net
What's new? Click here for the sites update log
Retro 8bit computing
Pong central arcade
Test and measurement projects
Misc. projects
Analog computing experiments and projects
Boat anchor repair and restoration zone (a serviceman's log)
Design resources
Opinion Blog  political and other, not necessarily electronics related
Tandy / RadioShack TRS80 Model 1 clone
A fullyfunctional clone and improved groundup hardware redesign of Tandy Corporation's famous home computer from 1977. 
Commodore PET2001 clone
A fullyfunctional clone and improved groundup hardware redesign of Commodore's first true personal/home computer. 
Oscilloscope Pong for one or two players A paddleandball game that renders simple vector graphics on an oscilloscope screen, but with a twist  the circuitry is implemented entirely in discrete components, all soldered together “dead bug” style over a sheet of bare copper laminate. Over 300 individual semiconductor devices! 
Video Pong for one or two players A little bit of craziness – a video display version of Pong implemented entirely in discrete component circuitry, soldered together “dead bug” style over a rather large sheet of lacquered copper laminate. Some features:

An ultra low noise measurement amplifier A fixed gain, JFETinput amplifier for laboratory noise measurements. Basic specifications:

A NAND gateonly frequency counter A sixdigit frequency counter with leadingzero suppression implemented entirely in NAND gate logic. Complete I.C. complement:

A simple audio oscilloscope An audiobandwidth solidstate oscilloscope with a fully synchronised linearsweep time base implemented with only six bipolar transistors and two silicon diodes! 
A prototype 2inch C.R.T. composite video monitor A prototype 2” C.R.T. composite video display monitor knocked up one rainy weekend. 
GK1 analoghybrid computer system

A Fourier synthesis character generator An alphanumeric display unit in which Fourier synthesis is used to construct the individual characters. 
A threedimensional projective unit An analogue computing aid which maps objects defined in three dimensional Cartesian coordinates (x, y & z) to a two dimensional XY oscilloscope screen. The projection of the object is fully rotatable through 0360 degrees on both the x and y axes of the object. 
A magnetic deflection display unit

A Rössler attractor circuit An electrical analogue of the famous Rössler attractor. 
A hyperchaotic Rössler attractor circuit An electrical analogue of the fourdimensional hyperchaotic Rössler attractor. 
A Lorenz attractor circuit An electrical analogue of the famous Lorenz attractor. 
Sprott Systems Circuits Electrical circuit analogues and oscilloscope display photos for chaotic Sprott Systems B through S. 
A selfprogramming analog computer for chaotic Sprott systems An analog computer designed and built to experimentally simulate chaotic Sprott Systems A through S. 
Telefunken's bouncing ball in a box: an analog simulation My implementation of Telefunken’s once famous analog computing demonstration problem. 
My analog computing bookshelf Books on this arcane art that I’ve collected, sourced mostly from online books sellers via Abebooks. If you have a passing interest in analog computing, here are some suggested titles to look for. 
Coefficient tables for active filter design. Highpass, lowpass, 2pole through 10pole

China’s totalitarian idiocy and the rise of the coronavirus. 