The CoCo did not have any sound hardware beyond a couple of ways to driver the speaker directly from the CPU. Where other machines had POKEY or SID or some variant of the AY-3-8910 to do the heavy lifting for audio, the 6809 was the CoCo's sound chip! This provides some flexibility, but it does make producing audio a burden for the programmer...
I had feared that having in-game music would require a lot of hand-crafted code modifications to perfectly time audio updates according to cycle counts in the instruction stream. Fortunately, there is enough time left in each frame to produce a reasonable (YMMV) audio stream. The time spent running the code produces a low-frequency hum in the audio, making the overall sound seem a bit like the speaker is behind a fan. The tone probably horrifies a lot of audiophiles, but I think it is a clear win versus no sound at all! I hope others agree...
I was a bit apprehensive about releasing another beta. It is no secret by now that I would like to do a cartridge release of Fahrfall, and I am a bit afraid that I might cannibalize my market by releasing a nearly complete version to the world for free. Still, I want everyone to enjoy the new Fahrfall and more testing never hurts!
Real fans will still want the cartridge. Besides, a few less cartridges sold will mean a few less cartridge cases for me to make! Anyway...I may still squeeze in a feature or two before a cartridge gets released... ;-)
Today marks the middle of July, so we are half way through the Summer Challenge. So far I have made good progress on my code development, but done very little documentation on the "arts and crafts" part of the project. I definitely have some stuff to show there, and I think this seems like a good time to pivot in that direction.
So, get ready to learn a bit about casting plastic, sanding, drilling, applying stickers, etc...and as always, stay tuned!