VIDC20

The VIDC20 was a video display controller chip created as an accompanying chip to the ARM CPU as used in RiscPC computer systems.[1][2]

A simpler version of the VIDC20, the VIDC1, was used in the earlier Acorn Archimedes computers.

A VIDC20 chip controls both the computer's video and sound.

The data is read from the 64-bit ARM data bus using DMA control and then processed and converted into the necessary analogue signals to drive the video output displays and sound system. The VIDC20 can handle many more display and sound formats than the original VIDC1 chip found in the Archimedes hardware. It can also read data from VRAM if installed in the machine, otherwise it reads from DRAM.