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From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Commodore 68020
Message-ID: <2801@cbmvax.UUCP>
Date: Mon, 16-Nov-87 17:21:40 EST
Article-I.D.: cbmvax.2801
Posted: Mon Nov 16 17:21:40 1987
Date-Received: Wed, 18-Nov-87 06:51:09 EST
References: <5338@cisunx.UUCP>
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 34

in article <5338@cisunx.UUCP>, ejkst@cisunx.UUCP (Eric J. Kennedy) says:
> 
> Can this 32 bit memory be used along with 16 bit memory expansions?

Yes, absolutely, no problem.

> If so, how does it work?  I.e. what determines which type of memory
> is used if both types are available to the system.  

This memory looks just like any other FAST memory.  Given that it is, by the
definition of the way we make the Amiga OS see the memory as autoconfig memory,
the first memory card configured, it is also, given the way AllocMem() works,
the first memory to get used when you allocate FAST RAM.  Providing you run
SlowMemLast to get $C00000 out of the way.

> Also, I seem to remember reading that CSA's Turbo-Amiga has a 12 Meg
> limit of 32 bit memory.  How does that work?  Just what are the limits
> with a 32 bit system?  

The 68020 is limited to 4 gigabytes, but real-life systems don't give you all
that much.  Our card doesn't offer 32 bit expansion, just the 2 megs on the
card.  I think CSA sticks their memory outside of normal autoconfiguration
space, perhaps up above the 68000 24 bit addressing limit.  CSA provides an
add-on extension connector on their board, but no on-board RAM.  If they're
limited to 12 meg of expansion RAM, that's a limitation of their specific
implementation, not of the Amiga system as a whole.

> Thanks,
> 
> Eric Kennedy
-- 
Dave Haynie     Commodore-Amiga    Usenet: {ihnp4|caip|rutgers}!cbmvax!daveh
   "The B2000 Guy"              PLINK : D-DAVE H             BIX   : hazy
    "Computers are what happen when you give up sleeping" - Iggy the Cat