[Coco] Coco Sound Format (Was: Sierra games with sound!!)

[Guillaume Major]

> Guillaume, would you post the details of the Sierra CoCo sound file 
> format here?  I and others would be interested in seeing them.

The sound format used by the coco interpreter is really simple compared to 
the standard AGI sound format. The coco interpreter only supports one voice 
so there is no need for a header. A coco sound consists of a series of notes 
and a footer. Each note is represented by 4 bytes:

Byte 1: tone of the note

00 - C3
01 - C#3
02 - D3
03 - D#3
04 - E3
05 - F3
06 - F#3
07 - G3
08 - G#3
09 - A3
0A - A#3
0B - B3
0C - C4
...
and so on.

Byte 2: volume

Unfortunately, there's only 2 levels of volume: on (0x3F) and off (0x00)!

Byte 3: note duration (MSB)

Byte 4: note duration (LSB)

Note duration unit is 1/10 of second.

The sound is terminated with a footer. The footer consists of 3 bytes: 0xFF 
and two unknown bytes. I did not figure out yet what the last 2 bytes do but 
they do not seem to affect the sound at all.

Well, that's it!

For more details you can have a look at my cc3snd utility source code at 
http://goyim.dyndns.org:8080/coco/AGI Utilities/.

Guillaume