It is kind of hard to experiment manually with sound effect generation for the Creativision and CVBasic.
So I decided to repurpose my Intellivision sound editor (you can see it at https://forums.atariage.com/topic/32035 ... ct-editor/) and use the bigger screen space available in the Creativision.
The method of work is showing a list of frequency/volume/note/volume, where each item in the list will be played for one video frame (if Speed is 1) or each tone over several frames (again controlled by Speed). This means you are editing only a single channel of audio (because you could have music playing in the background), and in the case of the SN76489 chip used in the Creativision at the same time a noise channel.
Adding more frequencies to the list is controlled by pressing 5, or removing the last item by pressing 6.
You move over the list to edit frequencies (8 items are shown, but the window can move up and down if you have more, up to 20).
To edit frequency press 1, the limit for SN76489 is 0-1023, where lower numbers are acute sounds. The volume is edited pressing 2 (0-15, 0 is silent, 15 is highest volume, 12 is reasonable).
To edit the noise mode press 3 (values admitted are 0 for no change, or 8-15 for selecting the mode per the SN76489 datasheet). Also you need to press 4 in order to edit the noise volume (again 0. is silent, 15 is the highest volume)
To play your sound just press 9, and to show the CVBasic source code press 0.
Alternatively your sound can repeat endlessly while you work (toggle with 8), and you can edit the frame speed for frequencies pressing 7.
As you can see the keypad reference stays on screen (something not possible on the Intellivision)
Enjoy it!
P.S: A video showing usage of the sound effect editor on the Colecovision https://youtu.be/C8DPRgD1Ouw
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