== Introduction ==
In 1990 Amstrad introduced the "Plus" series which tweaked the hardware in many ways and added a cartridge slot to all models. Most improvements were to the video display which saw an increase in palette to 4096 colours and gained a capacity for the capability of hardware sprites. Splitting the display into two separate windows and pixel scrolling both became full supported hardware features although both were possible on the non-"Plus" hardware using clever programming of the existing Motorola 6845.
An automatic DMA transfer system for feeding the sound chip was also added but the sound chip itself remained unchanged. Additionally, the BASIC command set for disc access was improved.