Changes
PSG
,This register is not used in CPC computers. In detail, a AY-3-8910 sound chip would have external connectors for this register, so that it could be used as a further IO port, but the CPC's sound chip (AY-3-8912, in 28 pin package) doesn't have such connectors, even though the register still does exist internally.
The [[Aleste 520EX]] (russian CPC clone) is a special case: does have a 8910 chip, with PSG Port B being used as 8bit printer port data.
<br>
Volume 0 is indeed silent. It is not just logarithmic attenuation where maximum attenuation of a channel is just very quiet and not silent. [https://forums.nesdev.org/viewtopic.php?p=236734#p236734 Source]
<br>
== Mono and Stereo Output ==
When using the CPC's external stereo jack, channel A is output to the right, channel C is output left, and channel B is output to both left and right, in that case channel B is output through a bigger resistor to prevent that this channel appears louder than the others.
Otherwise (when using the built-in speaker), all three channels are mixed at the same intensity. This signal appears to be also sent to the Tape output line also, so a connected Data Recorder could be used to record CPC music also.
<br>
