Newsgroups: comp.sys.atari.st
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!comp.vuw.ac.nz!actrix!Roger.Sheppard
From: Roger.Sheppard@actrix.gen.nz (Roger Sheppard)
Subject: Re: More than 4 Meg ??
Message-ID: <1991Jun07.130323.28009@actrix.gen.nz>
Organization: Actrix Networks
References: <1991Jun7.004215.1721@ncsu.edu>
Date: Fri, 07 Jun 1991 13:03:23 GMT

In article <1991Jun7.004215.1721@ncsu.edu> twmanino@eos.ncsu.edu writes:
> >>Nope. TOS 1.6 has a screwed up memory sizer that assumes that if two banks of
> >>RAM exist then both banks are the same size. I don't know if this is a bug
> >>in the true sense or malicious crippling but it is sad.
> >>
> >>BTW, a bank is two SIMMs since memory access is on a word basis.
> >>
> >>	512K	= 2 x 256K SIMMs
> >>	1Mb	= 4 x 256K SIMMs
> >>	2Mb	= 2 x 1Mb SIMMs
> >>	2.5Mb	= 2 x 1Mb SIMMs + 2 x 256K SIMMs (Not with TOS 1.6)
> >                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >I heard this works on TOS 1.6 if you put the 256k SIMMs as the first bank
> >and the 1M SIMMs as the second bank.  But I could be wrong.  If you're
> >having trouble, though, it's trivial to try it the other way.
> >>	4Mb	= 4 x 1Mb SIMMs
> 
> There's a file at atari.archive that fixes the 2.5 meg problem... It's called
> SIMMFIX.
> 
> You put it in your auto folder.  It reprograms the MMU, then does a warmstart.
> 
> I get 2 bombs on the first boot attempt, but when the machine resets, it does 
> just fine.  Any subsequent warmstarts just boot right up.
> 
> Be sure to read the instructions....
> 
> 
> Hope this helps,
> Tony
> twmanino@eos.ncsu.edu


Get Version 2 of simm fix, it states that the problem is with the OS
and not the MMU, I have played with a STE with 2.5 megs and found no
problems ?? and the MMU had the correct bits set in it..


-- 
***  Roger W. Sheppard        *    Roger.Sheppard@bbs.actrix.gen.nz  ***
***  85 Donovan Rd          *  *   At least I don't Flicker, not     ***
***  Kapiti New Zealand..    *     like a dying light globe. !       ***