Classic Macintosh software can be created using Retro68.

Documentation Inside Macintosh: https://dev.os9.ca/

PLD archive: https://wiki.pldarchive.co.uk/index.php?title=Category:Macintosh

256 colors on SE/30: https://zigzagjoe.com/30Video.html

Serial cables: https://www.colino.net/wordpress/archives/2026/05/11/the-macintosh-serial-cable-mini-din-8-590-0552-a/