Sound Capabilities

The Datalink is capable of playing 14 tones by poking one of the following values into PORT_SOUND (location $0028).  From experimentation, it appears that only the low nibble of whatever value is poked into this location is actually used.

It is my current working theory that there is a timer routine in the the Datalink which is actually causing the resulting frequencies and it might be possible to generate other sounds by going through a slightly different mechanism to poke the sound hardware.

Note that if you use the builtin sound routines for playing sounds, you will find that the interrupt routines will happily readjust the hardware tones behind your back.

Hardware Tones

0	Tone_END - This seems to generate silence
1	Low C
2	High C
3	Middle C
4	Very High C
5	High F (Reported to be a little bit lower than F)
6	Middle F
7	Low F
8	Very High G# (G-Sharp)
9	High G# (G-Sharp)
10	Middle G# (G-Sharp)
11	Low G# (G-Sharp)
12	High D
13	Middle D
14	Low D
15	Silence