==Amstrad Plus specificity==
The Amstrad Plus range include DMA sound channels. Each HSYNC, 1 instruction per active DMA channel is read. Each channel executes an instruction which allowed looping and sending data to AY registers. Each DMA channel is effectively a an AY register playlist and once started is executed without CPU intervention. It was meant to reduce the strain on the CPU.
This feature offered extra capabilities including 15 kHz sample playback.