Clock

In cartridge systems
The main system clock is 24MHz. It is generated and divided by 2, 4 and 24 by NEO-D0 to form the 12MHz clock for NEO-ZMC2, the inverted 6MHz one for the video DAC and also the 1MHz one for NEO-B1 (?).

LSPC2-A2 divides the 24MHz clock to 8MHz for the YM2610 and 4MHz for the Z80.

The cartridge connector provides access to the 24, 12, 8MHz and 4MHz inverted clock signals.

A second quartz is used on NeoGeo systems for generating the color burst frequency for the video encoders.

"B" signals are phase-inverted.

In CD systems


NEO-GRC ?