Path: utzoo!attcan!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga.tech
Subject: Re: 32-bit LUCAS memory board
Message-ID: <5337@cbmvax.UUCP>
Date: 28 Nov 88 22:35:43 GMT
References: <527@acp.OZ>
Organization: Commodore Technology, West Chester, PA
Lines: 40

in article <527@acp.OZ>, sns@acp.OZ (Stuart Nixon) says:
> Summary: How about 1Mb x 1 RAM chips?

> Me, I am happy to use AddMem. It also has the advantage that I can selectively
> disable the RAM if I choose for some reason at bootup (for example for memory
> tests, or for performance measurements)
> Any comments?

As I mentioned to Brad on BIX, if the memory doesn't support 24 bit DMA,
it really should be located outside of the 24 bit space, and at that point
is can't be autoconfiged.  However, you can probably do a little be better
than a generic AddMem.  It's reasonable to write a program that knows 
about that particular memory board.  If you have different possible size
options, the program could just as well snoop out how much 32 bit RAM is 
in place.  And of course the memory list that's created could be named
LUCAS-RAM or something like that.  I may have an example program that does
this completed soon (actually, I have one right now that does this kind
of thing, but it's not fully working).

>> 	I would like to move the kickstart area into this 32-bit wide path.

> I read somewhere that moving Kickstart to 32bit RAM/ROM does not have that
> big an impact on speed. Perhaps Dave Haynie could comment?

Who, me?  32 bit wide ROM Kernel does help some.   For instance, the FFP
libraries are in ROM, and if you load them into 32 bit RAM, they'll run
around 4x faster than out of the real ROM.  Layers seems to go faster too.
Lots of other stuff is blitter or I/O bound -- in those cases, you don't
notice a speedup all that much.  If you've got an MMU, this is a freebie.
If not, it's probably worth some work, but it remains to be seen just how
much.

>>                                 Brad Fowles

> sns      Stuart Nixon Software

-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession