Re: ramfast-ramkeeper-transwarp combo question

[mswaine681@aol.com]

On May 8, 1:14 pm, a2avia...@gmail.com wrote:
> All this FUD about DMA and the IIgs.
>
> Just plug it all in.
>
> Plug it in. DMA happens when it can, and doens't when it can't. The
> computer isn't just going to crash.
>
> If it does, I can assure you the problem is not because it did DMA
> into the upper 4MB space.  It did it 'cause something is bad.
>
> I've only ever seen a DMA crash once. The Ten Speed motherboard died
> hard when booting with a TWGS and RAMFast in it.
>
> Makes you wonder why the ROM 3 was delayed 4 months.
>
> --
> tdiaz {at} apple2(dotsero)0rg.

I am actually very flattered that you (I've gotten a lot out of your
various posts over the years), responded, but I guess I should have
explained my problem a bit more. I intend to drop a lot of money on an
accelerator for my ROM 3 and I want to get the most bang for my buck.
Specifically, I want to maximize the system for using SIS. Of course
the machine won't crash, but I don't know much about the relationship
between processor speed and DMA as it relates to actual performance.
For instance, does a 7 mg Zip GS with a 1 meg Ramfast doing DMA run
'better' than a Transwarp 10 sans DMA? or are they close enough in
real world performance that either combination would work equally
well? In short, if you were dropping $300+ for an accelerator with my
layout, would you look for a Transwarp or a Zip?

BTW, The post from CVA states "The Transwarp GS was not designed in
strict accordance with the processor it replaces....and prohibits the
new DMA circuit from putting valid bank latch data into the memory
expansion product...Therefore, if you have a TWGS you will not be able
to DMA above four meg....The Zip GS does not have this design flaw". -
So no DMA with my layout. I just don't know if this should worry me.

Mark Swaine