Barry Nelson In that case, the hardware is pretty simple. It consists of two address that you write to, one for the left channel, and one for the right. Whatever value you write there sets the instantaneous voltage value on that port. $FF7A (65392)-$FF7B (65404) Orchestra-90 $FF7A Left Channel $FF7B Right Channel ReplyShare2y David Moak So, no separate registers for voices, that’s all done in softwares? ReplyShare2y Barry Nelson David Moak Quote: So, no separate registers for voices, that’s all done in softwares? Exactly. It is slight better quality than the builtin DAC, and it’s stereo though, but all the tone generation is done by the CPU. ReplyShare2y Tony Jewell Yes! Basically, the Orch90 cart is just a pair of DACs wired up to the left and right channels. Absolutely everything else is done in software.

In that case, the hardware is pretty simple. It consists of two address that you write to, one for the left channel, and one for the right. Whatever value you write there sets the instantaneous voltage value on that port.

So, no separate registers for voices, that’s all done in softwares?

Yes! Basically, the Orch90 cart is just a pair of DACs wired up to the left and right channels. Absolutely everything else is done in software.