This is a CMOS component, different from the NMOS version. However, just because the CPU says 12Mhz does not mean that it runs on this frequency. It is just the maximum frequency the CPU has been qualified for.
If there is no other modification on the board, then that just means that a diffferent CPU typie has been installed - it would then still run with 7Mhz.
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Yep, its just a Hitachi CMOS cpu. Its not very likely that the system is overclocked.
That processor, if its anything like Motorola's CMOS 68000s is probably good for even more than 12MHz.
But 68000s, no matter how highly clocked aren't going to match a Vampire, or an '020, '030, '040, or '060 for that matter.
So if you really want to build a high performing system, you're going to need an accelerator.
