[Coco] My introduction - a newbie

[L. Curtis Boyle]

On Fri, 26 Jan 2007 23:54:32 -0600, Joel Ewy <jcewy at swbell.net> wrote:

> Dan Olson wrote:
>>> With an Orchestra-90 or Speach/Sound cartridge, the Color Computer 3
>>> sound is spectacular.  Using just its own built-in circuitry, the sound
>>> is barely adequate.  In other words, about ten times better than a  
>>> C-64.
>>>
>>
>> I always thought of it this way, the CoCo has great sound hardware, it
>> just doesn't come standard with the computer.  BTW, I never found much
>> info on the Orchestra-90 or Speach/Sound cart, I assume both are
>> incompatible, which has the best software support?
>>
>>  	Dan
>>
> I haven't really looked into this question in detail yet, but what I
> gather is that there are a number of RS-DOS games that can use the SSC,
> but that the Orch-90 is the only one that works at 2MHz (without
> modification), so the SSC can't be used in (Nitr)OS-9 LII on the CoCo
> 3.  Any emulation or reimplementation would have to fix that problem.
> (More likely the problem simply wouldn't arise because all the logic
> gates in an FPGA should be capable of the same clock rates, and software
> emulation is, well, software.)  I think maybe there is a program that
> will play WAV files through the Orch-90 in OS-9.  Am I right about any
> of this?

    Yes. I made a version of the PLAY command for OS-9/Nitros9 that could  
play 8 bit Mac, 8 bit Amiga, 8/16 bit uncompressed WAV, and 8/16 bit u-Law  
compressed/uncompressed Unix sound files.

>
> The Orchestra-90 is just a stereo 8-bit audio DAC, and if I understand
> correctly, the SSC is a (monaural?) FM synthesizer and hardware speech
> synthesizer.  If that's approximately right, then they really perform
> complementary functions.  PC sound cards have both functions, and an
> updated CoCo design should as well.  And if it's going to be able to
> play digitized samples as well as synthesized sounds, it might as well
> incorporate these two existing designs.

      Yes, I agree. The Orch-90 is basically just 2 8 bit DAC (the Coco has  
a 6 bit DAC mono built in), while the SSC is a separate sound/speech  
processor, which can run on it's own after you send commands to it. The  
advantages of the Orch-90 is that it works with double speed, and that any  
8 bit sound samples can be sent to it. It also doesn't require additional  
masking/shifting of bits like the built in 6 bit DAC does, so it takes a  
little less cpu time. Soviet Bloc and Gems by Scott Griepentrog support  
the Orch-90 with stereo sound (although it doesn't use any samples, just  
simple beeps).
>
> JCE
>
>



-- 
L. Curtis Boyle