@Kenny,

Yes, I'd agree that the custom chips definitely make the C64.
Since I'm a fan of 68000 based systems besides the Amiga, there the use of a custom chipset isn't as important to me.

In fact, the systems I worked with in the late '80s were rather generic using a off the shelf ET4000 based video card.
Then again, gaming was NOT part of our market.

@Andreas

>> The Soc Hepler is quoted as mentioning that would provide backward (Amiga) compatibility

>Can you point me to this mention?

Its not a direct quote, so it could be hearsay.

And would Commodore have bothered to add this? I'm unsure.

In any case, examining the plans for Hombre, I'd have to say that it doesn't look that promising.
The approach reminds me of early TI accelerator boards.
From the documentation it looks like the PA-RISC cpu was incorporated primarily to be a video controller, and that in higher end applications additional processor would be used.

If that second cpu wasn't another PA-RISC processor, the entire platform begins to look kind of messy.