I command thee. Upload thine code.
Sorry. I'm thinking of putting some of my 8-bit source together, but you probably wouldn't be interested in the platforms ... old 80's home computers, and this isn't the right place for those.
For anything more modern, there are still legal successors, or active NDAs with existing companies that are still in place.
Just like westwood68 ... when you've been in the industry for a while (and it sounds like he only left a few years ago), there are a lot of goodies to share someday, but you don't want to piss off Nintendo, Sony, Microsoft or any of the big publishers with bored on-staff lawyers.
That's one of the nice things about the PCE ... it's manufacturer isn't in the game business anymore!
Lots of developer's old source code will eventually get out there ... and there will be a record of the early days for historians, but it's just going to take time (years).
Something that may happen sooner is old folks retiring and writing new stuff for the old platforms ... for fun.