Amiga 3000UX

[Dave Haynie]

In article <1991Jan17.034938.9679 at zorch.SF-Bay.ORG> xanthian at zorch.SF-Bay.ORG (Kent Paul Dolan) writes:
>pal at ariel.ucs.unimelb.edu.au (Philip Leverton) writes:

>   The Amiga's "chip" memory, to Unix, is like the frame buffer memory
>   on a graphics card. .... This might change in a future software release
>   -=] Ford [=-

>Don't fix this "problem"; it's the wrong thing to fix. Fix the '020 and
>'030 add on cards so that they can support more than 4 Meg of memory, or
>provide a CBM 32 bit in the box expansion memory card that works with
>them, and let Unix continue to think chip is off limits; 

The A2620/30 memory can't easily be extended on-board.  The A2620 is really
limited to the 4 Megs of 32 bit memory, plus any 16 bit memory you could add
(which isn't going to be favored by UNIX).  There is a way to move the 32 bit
memory of the A2620 up to $01000000, thus freeing up the expansion bus for
up to 8 Megs of 16 bit RAM.  Not great, and you'd lose some disk speed, but
the 16 bit RAM should be faster than paging.  Realize that 4 Megs of RAM seemed
pretty good back in 1987 when we started the A2620 and only had to deal with a
plain SVR3.  I doubt UNIX is clever enough at the moment at least to handle 
such a mutant A2620, but you never know.

The A2630, as mentioned elsewhere, can support a large add-on memory 
daughterboard.  Though none currently exist.  At one point, UNIX knew about
this kind of memory, though I have no idea if it still does.  

>Kent, the man from xanth.


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
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