"CPC Plus" range
Basically: extended colour palette, hardware sprites, smooth hardware scrolling, DMA controlled sound
In detail (from http://www.cpcoxygen.net/magazine/04/18/18b.html
o 16 Hardware Sprites at 16 x 16 pixels, made up of 16 colours from a palette of 4096. Impressive when you take into consideration that each sprite palette is independent of the screen mode and can be magnified to double or quadruple size.
o Smooth hardware scrolling both horizontally and vertically. The original CPC only had limited vertical scroll.