[comp.sys.atari.st.tech] 2.5meg STe

ekrimen@ecst.csuchico.edu (Ed Krimen) (01/25/91)

Today I received two 1-meg SIMMs.  $88 (including shipping and 
handling and VISA surcharge) was the cheapest I could find.  I got
them from Peripheral Outlet (800-332-6581).

Anyway, so I pop open my STe.  (Actually, those who've done it know 
it's not just 'popping' it open. :^)  I pulled out the four 256K SIMMs 
and installed the two 1-meg SIMMs.  One of them I put in the slot 
closest to the rear of the machine and the second, I put in the third 
slot from the rear of the machine.  I closed the hatch, booted up, 
and, as John Madden would say, "BOOM! Two megs!"  Being the 
inquisitive type, I wanted to see if I could get 2.5 megs using two 
of the 256K SIMMs I had left over.  It's a good thing I didn't replace
any of the screws.  I've heard that this can't be done (mixing the
SIMMs, not replacing the screws :^), but someone on here a couple of
months ago said he did, and he didn't use SIMMFIX.PRG.  (When SIMMFIX 
is loaded, it reprograms the MMU and sets _memtop.)

I popped open my STe again and installed the 256K SIMMs in the empty 
slots.  The docs to SIMMFIX say that the machine would stay in a 
continuous reset-reboot cycle because TOS 1.6 doesn't program the MMU 
correctly and "any non-trivial programs (e.g. GEM)" will cause the 
crash.  Without SIMMFIX installed, I turned on my STe and everything 
was fine.  GEM was there including some desk accessories and TSRs.  I
checked amount of free RAM with several utilities and it said that I
had 4 megs.  I was kinda expecting this, so I wasn't surprised.  I
then tried memory test programs.  One wouldn't load at all.  The AERCO
tester gave me a <Sense $25> error and had trouble reading the hard
drive AFTER I hit any key to start the memory test.  I thought this
was kinda strange 'cause it's supposed to check RAM not the hard 
drive.  Another one from New World Software lets me configure how 
much RAM I want to test.  So I tried 2.5 megs and I stopped it after
it had gone through 2 successful tests.  Then I set it to 4 megs and I
didn't get ANY errors.  I knew that was the wrong one to use.

So I loaded a bunch of memory hogs.  It's pretty easy filling a meg, 
but I never would imagine how difficult it would be trying to fill 
4megs.  I loaded a ton of stuff and I could tell that it had 
passed 2.5megs because garbage started being written to the screen 
and then it crashed and locked up.

In any case, it seems that my machine is working fine with 2.5megs, 
but all the free RAM indicators are telling me how much free RAM I 
have out of 4megs.  Does anyone know of a program I can put in the 
AUTO folder that sets _memtop to 2.5 megs, without having to reboot
like SIMMFIX?

Thanks for the help.

-- 
         Ed Krimen  ...............................................
   |||   Video Production Major, California State University, Chico
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