Aaron Cake has many electronic circuits and other electronics information in his archive that is online since the 90s. Antique electronics and Parallel Port Programming.
Begin With the Basics - Learn about static electricity and how to make magnets and solenoids. Find out about direct current and alternating current. Then learn about electrical circuits that use batteries and lamps.
TRS-80 Computer Whiz Kids - appeared in 1984. Eight issues in all are known to have been published, the last appearing in 1991.
The Electronics section of Changpuak, has calculation tools for electronic circuits as well as some electronic projects like power supplies, signal generators and curve tracers too .
Hardware Book. Internet's largest free collection of connector pinouts and cable descriptions. Connectors, Pinouts for connectors, buses, Cables, How to build serial cables and many other cables. Adapters How to build adapters. tables with info. like AWG.