Re: cine sound board

At 11:45 AM 6/10/97 -0500, you wrote:
>>
>> ..interesting, I've been thinking of doing pretty much the same thing
>> for the Sega vector games. Any chance of getting samples / development
>> tools :-)
>>
>
> I've actually been trying to find out how to do that over the past few
days, but I haven't gotten too far. It seems that we use a "different" type
of distribution here.
>
> I'm sure that I can get you samples. I'm not so sure about the
development tools. But let me look into it.
>
> I've been putting a bunch of hours into this project over the past week or
so, and I'm hoping to have an initial MATLAB model of my version (of just
the Star Castle Sound board for now) soon. Anyone who has access to MATLAB
should be able to hear my emulated versions of the sounds....
>
> I was looking through the archives of this list and I saw that there was
some discussion a while back about the 3 pin analog noise generators. Did
you guys ever emulate these digitally? If so, you'd save me a bit of work.
I need to find out how that puppy works (i.e. its noise spectrum.)
>
> I think you guys were talking about using an LFSR, generated by a PIC to
do that. Did that work?

I haven't done it with a PIC (but have with a 6800, 6809, Z-80 and a 8088),
the technique works fine. It's a very simple "shift, rearrange some bits,
XOR" algorithm. Works just like the schematic on one of those Cinematronics
games (I can't remember which games used discreet components to implement
the shift register / noise generator. I thought Star Castle did.)

It's drawback is the noise generated doesn't have a lot of low end
component. It works great for gunshots, but lacks real low end rumble on
ship explosions.
So for the games that used the noisy semiconductor approach (Space War,
Sundance, Tailgunner(?), I think I'm missing one) the explosions won't sound
nearly as cool.

-Zonn
Received on Tue Jun 10 11:40:29 1997