I have the original game on CD, is there some way I can activate it on Steam?

[Hyper]

[Tori-Jima]

I don't know if it's still possible but it was, since i did it with my games as well. You have to contact the Sega support for this. I had to take photos of your CDs including the serial numbers and send it to them and the support return will send you steam keys.

edit: just found a thread on this forum which says Sega doesn't offer this service anymore

[Hyper]

Yeah, I emailed them and got an automated response saying that they stopped doing code exchanges awhile ago.