An introduction to the Bit Preserve project by James Lewis. The aim is to generate proper schematics using KiCAD from (badly) scanned PDFs of schematics of various computers.
There is a decent book that discusses the technical details of the Apple IIgs, but it does not get into chip or board level design. For that detail, I had to look at the original schematics. While I am ecstatic that someone archived these original documents as PDFs, I quickly became frustrated. Sometimes the scan quality is not very good, and it is nearly impossible to search for symbols across multiple pages. I thought to myself, “There has got to be a better way!”
Instead of relying on these bitmapped documents, I decided to re-create the entire Apple IIgs schematic in KiCad. Why KiCad? Long story short, I settled on KiCad because it is an open source tool and has an accessible file format. Those two qualities make it ideal for preserving a schematic long term. For fun, I started streaming my efforts on Twitch. What surprised me is that people started contacting me about other computer schematics. A friend and colleague emailed me a ten-megabyte zip file with Commodore 64 schematics he collected over time.
So. I created a GitHub repository called “Bit Preserve.” The goal is to re-create schematic for vintage electronics using KiCad.