Rewriting a C64 emu from scratch will be a hell of a job. The chips in the 64 (VIC-II and SID) where so advanced, that it took years before they could be decently emulated. Therefore, if someone wants to write a C64 emu, it would be insane not to use existing program code for the VIC and SID. And since emulating the rest of the 64 is a piece of cake compared to these two chips, the emulation of these chips is most responsible for the final emulator speed.
Generally speaking, to emulate a certain system, you need a system with at least 30 times the processing power. With the 64 running at 1 MHz and the untweaked gp2x at 200 MHz, you would think that this rule is more than cared for. It just shows us how complex the chips are. It seems the SID is even "worse" than the VIC-II, although color mixing and border sprites also are a hell to emulate. It seems to me that even the very sophisticated Amiga chips are easier to emulate...
Btw. everyone is talking about Pandora, but what about the Wiz? I like its design more than that of Pandora (but that's personal) but most important, it brings a huge boost in raw processing power.
Edited by Squirrel61, 09 September 2008 - 07:00 AM.