Overclocking genesis CPU

I want increase CPU frequency of SMD’s core (PicoDrive and GenesisGXPlus too) to 100 Mhz, because it is need for some games (example dune2). What I need to change in source code of cores?

People have asked Eek to add it to genplusgx but he doesn’t seem too interested in it: https://code.google.com/p/genplus-gx/issues/detail?id=223

[QUOTE=hunterk;18282]People have asked Eek to add it to genplusgx but he doesn’t seem too interested in it: https://code.google.com/p/genplus-gx/issues/detail?id=223[/QUOTE]

As you know mednafen also have port of genesis plus. But there is only small change of source code:

max_md_timestamp = Main68K.timestamp * 7;

I found same (similar) in libretro-genesis plus gx:

/* 68k cycles should be a multiple of 7 */ m68k.cycles = (m68k.cycles / 7) * 7

But if I’m changing it, there is no effect in cpu’s frequence

we don’t have a mednafen genesis core