Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site trwrba.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!pyramid!hplabs!sdcrdcf!trwrb!trwrba!mdf
From: mdf@trwrba.UUCP (Mark D. Falleroni)
Newsgroups: net.micro.atari16
Subject: Upgrade help needed
Message-ID: <1980@trwrba.UUCP>
Date: Tue, 8-Apr-86 08:52:17 EST
Article-I.D.: trwrba.1980
Posted: Tue Apr  8 08:52:17 1986
Date-Received: Sat, 12-Apr-86 22:51:06 EST
Organization: TRW EDS, Redondo Beach, CA
Lines: 22


Help! The local electronics store just finished installing
the second upgrade in my ST.  On boot-up, a ram-size program shows
about 901-902K available.  Using MDISK, I allocate a 720K ram disk and
place the development C compiler (all 3 programs) and a source file
in the ram disk.  I start compiling and when the second pass of the
compiler is to be loaded, anywhere from 2-4 bombs consistently appear.
If I reboot, and allocate a ram disk < 300 K, the source compiles without
error.
  The upgrade was installed with resisters and 150 ns. rams.  It appears
that the larger ram disk forces the compiler to be loaded in the upper
512K of ram.  Does the above description indicate an addressing error?
Is the MMU chip bad?  I noticed that when pin 18 of the MMU chip (RAS)
is touched with an oscilloscope probe, the screen goes bananas.  The 
same thing happens when the RAS pins of the upgrade are touched.
I sure would appreciate any help on this one.

		thanks,
			Mark Falleroni
 			TRW Ogden Engineering Office
			Ogden, Utah 84401
			<mdf>