Re: Crystal's new chip

> So a friend of mine has been playing with some of the newer
> "Synthesizer-in-a-chip" line of IC's from crystal.
>
> A week ago he was on their home page, or maybe it was email from a sales
> guy, but they've recently announced a new chip that is very similar in power
> to an AWE32 type of sound board.
>
> The spec I saw included a full table look up that is stored in an "external"
> ROM or DRAM. It does full attack/decay on each sound, includes special
> effects (reverb etc) and a built in mixer. I think it said it could play 32
> simultaneous sounds out of a library of over a hundred (depends on storage).
> The wave table storage can be a 1meg (bytes) of compressed ROM. I think
> they were asking $15 quantity 1, kind of prices. (Please correct me if
> anyone has the time to visit the site, or maybe Joe knows off the top of his
> head.)

        This sounds like the CS9236, "Single-Chip Wavetable Music Synthesizer." I was never directly (or actually even closely) involved with that product, but I had our "Product Selection Guide" in front of me....
 
> So it seems to me with four or five chips you should be able to create a
> universal sound/speech board for just about any game.
>
> You'd need:
> - All in one, wavetable synthesizer chip.
> - Wave table ROM programmed with game sounds/voices.
> - PIC processor to do the interface stuff -- and some glue depending on game.
> - Serial DAC (available from Crystal).
> - Op amp filter/driver.
>
> Optional:
> Audio power amp for the games that have this on the audio board.

        This would work for anything which uses periodic waves (most sounds.) The Cinematronics stuff is a pain, most specifically the Background noise in Star Castle, etc. It has a different motherboard interface, which basically sets the frequency of the background noise, rather than just being a "Loud Explosion Enable," etc like all the other sounds are.

        This remains to be seen, though, and by just increasing the rate that you step through the wave table, as a function of those motherboard inputs to the soundboard, I might be able to even get the background sound this way. This would probably involve using a PLL as the off-chip oscillator.
 
> Everything you need is there and there doesn't appear to be anything "to
> work out". At this point it just looks like engineering (hook up the parts
> on a board that can be plugged into the game, write the software, sample the
> sounds, etc). It's not going to get much easier.
>
> Any thoughts? (Especially you Joe, is this the IC you're using to derive the
> one you been talking about, for your Cinematronics sound card?)

        I agree totally. I was talking about my project to a co-worker, and he suggested exactly the same thing. However, I'm pretty sure that, at least for the Cinematronics stuff it needs to be a bit more complicated (for that $&^*(&(^&% background noise)

        For a "traditional" sound board I think that is the way to go.

        The way I am doing the Cinematronics multi-game soundboard is by using a DSP to generate the sounds and then send everything through a DAC. There are I/O pins on the DSP that I will just hook the inputs up to. If I run out of I/O pins (which I think I will) I will just generate ALL of the sounds simultaneously with the DSP. The part that I am planning on using will have some DACs onboard, and I can just use the motherboard inputs to mute the channels that I don't want. Something like that.....

        Since it is a DSP, I can use I/Os to control the frequency of background noise, etc.

        The part that I plan on using is the chip that I am working on, which hasn't been released yet. Take a look at the CS4922 and CS4226 datasheets (available from www.crystal.com) and imagine the best-case combination of the two, and that's basically what "my" chip is. Hopefully it will be "officially" announced soon.

Joe
 
Received on Mon Jul 7 11:57:39 1997