Clock

In cartridge systems
The main system clock (sometimes called mclk) is 24MHz. It is generated and divided by 2, 4 and 24 by to provide the 12MHz clock for, the inverted 6MHz one for video output and also the 1MHz one for.

As is clocked on both edges of the 24MHz clock, it is able to divide it by 3 and 6 to provide the 8MHz clock for the  and the 4MHz one for the.

The cartridge connector provides the, 12MHz, 8MHz and 4MHz inverted clock signals.

A second quartz is used for generating the color burst needed by composite video, for the video encoders.

"B" signals are phase-inverted.

In CD systems


NEO-GRC ?