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Old 05 August 2012, 16:53   #126
Join Date: Jun 2010
Location: out in the wild
Posts: 1,127
Originally Posted by ikonsgr View Post
I just wondering: From what i unsderstand so far, the on board 2mb ram of aca 500 is not fast ram (it's not reside in the 8mb pooll starting at $200000 right?)
You (and others in this thread) are making a fundamental mistake: You are trying to infer the type of memory by it's address. That's plain wrong. The accelerator is a completely new CPU/memory subsystem, which can control all access speeds and address spaces on it's own. I'm using this to my (and thus the user's) advantage by re-mapping $c0.0000 memory to fastmem and even relocate Kickstart to the accelerator's memory.

Originally Posted by ikonsgr View Post
Remove the 68000,then plug kippers2k ram card, and on top of that, plug aca 500! In that case, fast ram will also comunicate directly with the aca 500's cpu at full speed of 14Mhz, isn't that right?
Nope, the speed on the 68000 socket is 7MHz and can't be changed with a simple plugin-adapter. Trust me, any expansion that already exists doesn't make sense from a performance point of view. You need a faster bus to gain real performance. The ACA500 is not the fastest thing in the world, but adding 7MHz "fastmem" would slow it down to a point where you can't call it "accelerator" any more, because the 68000 does not have caches at all.

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