Long time ago, I read somewhere that SEGA, the company, has very little source code and hardware development artifacts saved from their Dreamcast days (and even earlier than that). They either lost or just junked majority of it as time went on.
Do other companies care so little about their own history? If I was running one of these companies, I'd save a copy of every game, console, HW development platform and source codes of every game in a vault somewhere.
That's part of the problem; standard practice for Japanese companies until rather recently (as in, within the past decade or so) was to physically print out a copy of the completed game's source code and stick it in a filing cabinet somewhere, never to be seen again. Most remasters of games released ~1995-2005 are based on beta code they happened to find on old workstations.
Japanese companies may be good at certain things, but by far and large most companies I have seen in Japan are really, really bad at documenting and archiving what they do. They work like the past stuff has no value whatsoever.
I don't know if this is true of the Dreamcast era Sega but it is for the Saturn era. They lost source code for some of their games.
A lot of Dreamcast games were ported to other console when the Dreamcast died
Do other companies care so little about their own history? If I was running one of these companies, I'd save a copy of every game, console, HW development platform and source codes of every game in a vault somewhere.