Changes
The Amstrad CPC,CPC+ and KC Compact use a AY-3-8912 Programmable sound generator (referred to as PSG in this document), operating at 1Mhz. This document will describe it's role in these systems. To understand the full functions please read the datasheet.
== Role of the AY-3-8912 ==
In these systems it is accessed through and connected to the [[8255]] PPI. (You should understand the operation of the 8255 if you wish to access the PSG)
The register data is available at PPI Port A.
=== Notes===
If the tone period is in the range 0-4 I can not hear any tone output.
out (c),c ;}
ret
</pre>
=== Writing to a PSG register ===
This routine can be used to write to registers on the PSG. C contains the index of the PSG register to write. A contains the data to write to the PSG register.
<pre>
;; entry conditions:
;; C = register number
ret
</pre>
== Links ==
