A2000 Accelerator question

[barney]

I see people on Ebay selling GVP Accelerators and mentioning in bold letters "NOT THE EC MODEL".  What really is wrong with the EC model?  Is there somthing about this model that is that awful?

Barney

[save2600]

Nothing really "wrong" with it. Just a cheaper design that does not support MMU and IIRC, that's the only difference.

[Karlos]

68EC020 also has a 24-bit memory addessing limit, which restricts you to a maxumum of 16MB into which you have to map your hardware, chip ram leaving at best 8MB for fast ram expansion.

I don't think the 68EC030 has this limit, but it is restricted to 40MHz and lacks MMU, IIRC. Not much of a problem, really, unless you want to play with GigaMem and the like.

[nikodr]

And of course any version of bsd or linux for 68k would not work as it needs mmu to work.In my opinion better to get one with mmu,who knows?Someday you may want virtual ram or unix/linux 68k.

[Damion]

Simple solution would be to replace the CPU if you need one with an MMU.

[Matt_H]

Simple solution would be to replace the CPU if you need one with an MMU.

...as long as it's socketed. I think some GVP 030s are surface mounted.

[save2600]

...as long as it's socketed. I think some GVP 030s are surface mounted.

Exactly. Most all of the lower end ones I've seen were. Makes sense... if you're trying to cut costs by building an accelerator card around an EC chip anyway.

[Damion]

Ah, forgot about the QFP ones, I was thinking of the A530 - came with an EC rated PGA CPU.

[a1200]

I bought a GVP Jaws II for my A1200 recently and it came with an EC 030, so I went on eBay and found someone selling full 030's @ 40MHz (he has other speeds and other 680x0 chips also). I have purchased one and am just awaiting its delivery. Not sure if I will ever use the memory management unit, but whilst you can still get hold of these chips, its worth getting one if the price is right.