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From: ericw@manta.NOSC.MIL (Eric Williams)
Newsgroups: comp.sys.mac.hardware
Subject: MacPlus Memory Upgrade Help Needed
Message-ID: <955@manta.NOSC.MIL>
Date: 1 Nov 89 20:25:35 GMT
Distribution: usa
Organization: Naval Ocean Systems Center, San Diego
Lines: 41

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>  From: krueger@mdcbbs.com
>  Message-ID: <559.254715ae@mdcbbs.com>
>  Date: 26 Oct 89 14:33:18 GMT
>  I'm looking for some assistance in upgrading the memory on a 3yr old MacPlus.
>  What is the best way to "crack" the case?  Do I really need to get one of
>  those special tools to open it up?  What are the chips/simms I need/can get?
>  Can I use 1meg or 256k chips?  I'm probably going to get the chips from
>  The Chip Merchant, since many netters recommend them.  By the way, I'm
>  thinking about upgrading to either 2 or 3meg depending on what my beastie
>  can handle.  Please send either e-mail or followups to this posting.  THANKS
-------

Ken,
  Well I have upgraded the memories on several MacPlus's so I can give 
  you the whole scoop.  First, you need to open the case.  That's the
  hard part.  You'll need to get a torx wrench, but it will need to be
  a long one, since the screws on the top are quite deep.

  After you get the case cracked, you'll need to take out the logic board.
  To do this you'll need to to unplug the power and floppy drive connector
  cables.  As you look at the board, with the IO ports being the edge
  close to you, you'll see four 256k SIMMS.  If you want to upgrade,
  you'll need to get either two or four 1mb SIMMS.  If you go with just
  two 1mb SIMMS, the SIMMS will need to be in the first bank, with 256k
  SIMMS in the second.  After you've installed the SIMMS you'll need to
  cut a transistor, which is located in the upper left corner of the 
  logic board.  This transistor is labeled:  256K BIT MASK  
  With this circut cut, the Mac will not be limited to use 256k SIMMS.
  Keep in mind that once this is cut, there is no going back.  You
  won't be able to downgrade to just 256k SIMMS.  And that's it.

  Opening the case is really the hard part.  So you can upgrade to 
  either 2.5mb, or 4mb.  
   _________________________________________________________________ 
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     Eric D. Williams                      Odds Against You?       
     Computer Resource Center              Need A Friend?         
     ericw@nosc.mil                        Call the CRC!         
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