I've been wanting to have these articles for a long time.
The beginning of Dreamcast (Katana) hardware development was certainly not Sega's first effort to find a successor or replacement for Saturn -- That actually began in late 1994, just before the Saturn launched in Japan, and continued through 1995 with Nvidia and Lockheed. As for the two internal pieces of hardware that competed to become what we knew as Dreamcast, I figure they must have been started sometime in 1996. By March 1997, Next Generation learned of one of them, and that's were this begins.
Some of you will find it pointless, others should find it quite interesting. I do hope you all enjoy.