----- Original Message -----
From: "Dave Hooper" <[EMAIL PROTECTED]>
To: <sam-users@nvg.ntnu.no>
Sent: 19. listopadu 1999 3:36
Subject: Re: New WinCoupe alpha test version (Was: Re: Defender)
> > > However, the VOLUME registers (ie, sound registers 0 thru 5) only
> provide
> > > 3-bit resolution when envelopes are enabled (normally they would
provide
> > > 4-bits resolution ... it's as if the SAA has gone thru registers 0 to
5
> > and
> > > ANDed with 0xee before using them, whenever envelopes are enabled).
> Weird
> > > biscuits.
> >
> > Er... don't you mean shifted them down 1?
>
> No, because that would imply that enabling envelopes immediately halves
the
> volume, which is not the case. The resolution just goes down. And I take
it
> you meant shifting-down-on-a-per-nibble-basis since each volume register
> encodes two amplitudes (stereo ... ) :)
>
> > BTW: It's because (I think) of the way the envelopes are used; they're
> > probably PWM based (as the rest of the chip is), and they're in the
> pipeline
> > after the volume generator. So, my guess is that what you've got is
this:
> [...explanation...]
> > Or something. Thinking about it, this is probably all totally wrong. :)
>
>
> Ummm ... Errr ... well it's probably something like that.
> Or it could just be some crazy kind of feature (after all, the fact that
> it's even POSSIBLE to generate 'samples' from the SAA is a kinda
> undocumented feature .. I'm sure the designers didn't set out to try and
> allow it. If they had they would've made it a damn site less weird ...
> Enabling envelopes and mute all channels ??)
> D a v e
>
I think playing samples is normal. Any sound chip like SAA1099
can play samples the same way. This is easy for hw designers,
since it doesn't need any changes or addtions to the chip.
You probably know how does it work in the real world hw, so
I don't go into details.
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Bc. Aley [eili] Keprt - student, programmer (multimedia soft. etc.)
e-mail: [EMAIL PROTECTED] *** http://get.to/aley
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