The standard [[video modes]] or '''Screen Modes'''.
As a Colour Personnal Computer, perhaps the Amstrad CPC better strength best argument (beside being cheap, fully equipped and well rounded) was his video capability. Yet this was also heavier for the Z80 to handle compared to other lighter diplayers such as ZX Spectrum.
Also Amstrad's Video RAM was shared on the Z80 RAM. This and a cheap conception with the fewer specific chip to ease the CPU could turn it into a sluggish snails if badly programmed.