On Wed, Nov 29, 2006 at 05:30:29PM -0600, aliensrcooluk at yahoo.co.uk wrote:
 SH1 was the CD controller? I thought it handled
 the sprites?
 The SH2's handled the polygon output (250,000
 each) of 500,000 polygons per second. 
The SH-1 was definitely in the CD-ROM subsystem - whether it could also be
used for other purposes I don't know.  As far as the SH-2's being used for
polygon output, wasn't that the job of the VDPs (the videochips - again two
of them, but both were different, and given different tasks - the VDP1 is
the main chip that does the polygons/sprites, and the VDP2 does
"backgrounds" and the video output itself ( I think these are like the old
SNES Mode 7 type backgrounds)?  The SH-2's would obviously have to do the
maths though, but I think they were somewhat limited by being on a shared
bus so they had to take turns on accessing main memory or the support chips.
There are PDFs of the official Saturn developer docs out there - should be
easy to find via Google, and they explain stuff somewhat better than me :)
 The board was nicknamed the "Titan" board
 and was still used well into the late 90's
 despite being superceded graphically by all
 of Sega's Model 1 & 2 boards (and Model 3
 board in 1998/9).
 However, due to it's mastery of 2D and 3D
 it was used on many arcade games (sorry,
 can't name any now, been too long since I
 last spoke about this board). 
There's a list on this site : 
http://www.system16.com/hardware.php?id=711
- it's also got information on a lot of other arcade boards.