Multigame webpage (and sega vector generator stuff)

I put together a little webpage with the Sega Multigame stuff on it. It
has progress estimates and some screen shots from the menu-system.

http://www.wwwpro.com/clay/sega_multigame.html

I finished about 95% of the menusystem this weekend. (Started over.) It
looks pretty good-- not as nice as originally planned, but pretty good.

I had a REALLY cool looking menu (all on one screen), multiple layers of
spinning twinkling stars and whatnot only to discover a "technical
innacuracy" of the current emulators...

Seems that the Sega vector generator has a certain number of "ticks" that
it uses to clock the counters every refresh period. Well, even if there's
plenty of free memory in your display list if you're drawing big (or
complex) stuff, it's possible to run out of vector-time while drawing.

So, my extra-cool menu system came out with a cool star background and
about one line of text when running on the "real" hardware. Whoops. :-/

I don't know if anyone other than I will ever program this thing, but if
you do it's worth keeping in mind.

Geeky observation of the weekend: If you run the G-80 hardware with an
oscilloscope in XY mode and with no z-input the last position of the beam
on the frame will leave a bright dot on the screen. How bright this dot is
is proportional to how much "free" vector generator time is left. (Since it
just sits there when the display list is done drawing...) Dimmer the dot,
the less vector time you have "left" in your display list.

-Clay

P.S. The current menu is actually pretty nice-- spinning star background
changes colors, press P1 Start to move the arrows, P2 Start starts the game
or selects the current menu item. If anyone wants to see it on MAME or
whatever let me know and I'll post some ROMs...

Clayton N. Cowgill Engineering Manager
_______________________________________________________________________
/\ Diamond Multimedia Systems, Inc. clay@supra.com
\/ Communications Division http://www.supra.com/
Received on Mon Oct 27 17:13:12 1997