== Overview ==
The 6845 Cathode Ray Tube Controller (CRTC) is a programmable IC used to generate video displays. This IC is used in a variety of computers including the Amstrad CPC, Amstrad CPC+ Plus and KC Compact.
The CRTC is a simple chip. It is made up of counters and equality operators, tied by simple logic. All the complexity stems from its multiple independent implementations with their subtle differences.