30 Nov
2006
30 Nov
'06
2:08 a.m.
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despite being superceded graphically by all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.