Sega Multigame - input needed!

Hi everybody--

Brief status update on the Sega Multigame. There's a couple questions
mixed in the text that I'd like input on...

Hardware:
---------
Hardware is near final. The daughtercard uses either a 27C040 or 27C080
(good idea, Ray). A 27C040 will be included. There are TWO 8-bit latches
on the board. Latch "1" uses four lines for bank (game) select, the other
four lines are for Audio selection.

Question #1: Should I use one line per soundboard for selection, or encode it?

ie:
0001 = Universal Sound Board
0010 = Space Fury Sound board
0100 = Eliminator Sound Board
1000 = reserved

OR

0000 = Star Trek
0001 = Space Fury
0010 = Eliminator
0011 = Tac/Scan
0100 = Zektor
0101 = reserved
...
1111 = reserved

The "one line per board" makes a simple little relay selector easier. The
encoded version gives more room for expansion-- at the expense of needing
more hardware to decode it. Doesn't matter to me, software's about the
same to write...

Latch "2" is reserved for expansion. (Specifically it's used to select
Portrait or Landscape monitor mode, and to control a couple of EEPOT's for
width control on the monitor from the menu software)

The "standard" control panel will be Star Trek. I'll try to adapt the game
code as best I can to allow use of the Star Trek control panel to play all
games. I still want a guaranteed unique code for each game to be output
 from the latches though, so latch 2 will do that if we leave latch one as a
simple "audio selector".

Software:
---------

After spending the weekend with Al's simulator I've concluded the following:

Space Fury. I think I've patched this to use Star Trek's controls. Warp
is rotate left, photon is rotate right, impulse is thrust, and fire is
fire.

Eliminator. I *might* be able to patch this to allow one player games
using the same controls as above. Kinda tricky since they do some funky
bit-packing with the input words.

Tac/Scan. I *was* going to patch this to reverse the impulse/fire
buttons to match up with Add Ship/Fire. It looks really painful, so I'm
inclined to leave it as impulse=fire, fire=add ship.

Zektor. Ditto above, except impulse=fire and fire=thrust.

Question #2: Does this sound OK to everyone? I'll put the original Space
Fury and Eliminator images in a couple empty slots on the EPROM in case
people want a to use those and make a "universal" control panel by adding
buttons to a Star Trek panel or whatever.

Test Modes. The menu-software is started by the non-maskable interrupt
(how you'd normally start the self-test) so the menu system will actually
allow you to run a self-test for a particular game instead. Of course, if
the boardset won't even turn on it's not going to help...

-Clay

Clayton N. Cowgill Engineering Manager
_______________________________________________________________________
/\ Diamond Multimedia Systems, Inc. clay@supra.com
\/ Communications Division http://www.supra.com/
Received on Mon Oct 13 12:33:26 1997