[comp.sys.mac] Upgrading memory

bskendig@phoenix.Princeton.EDU (Brian Scott Kendig) (05/12/89)

In article <3175@tank.uchicago.edu> wjb1@tank.uchicago.edu (Bill Buikema) writes:
>In article <111900060@uxa.cso.uiuc.edu> jth90342@uxa.cso.uiuc.edu writes:
>>Technology Works in Austin, TX has 100ns, low profile SIMMs with a lifetime
warranty for $159.  I am not associated with TW, but I have been immensely
happy with the service I have received in previous orders.
>
>I just called Data Memory Systems Co. in Lawrence, MA, and they quoted me a
>price of $150 for 100ns low profile SIMMs with a lifetime warranty. Their 
>number is (800)662-SIMM.  I have no association with DMS, but I may soon 
>order some of their SIMMs.

Let me get this straight, because Macintosh memory upgrades have always
confused me:

All I need to do is call one of these companies, say "Gimme two 1M SIMMs" (in
slightly more prosaic wording), fork over ~$300, pop open my Mac SE, swap
two of the existing chips with the two new 1M (each, right?) things, and
seal the whole tamale up again, and I'll have a 2.5M Macintosh on my hands?

Does anyone know of any better offers on memory chips?

Should I buy now, or hope that the prices will drop further?

And what, precisely, are DRAM chips, and are they a feasible (and cheap!)
option?

Any explanations to clear this up would be greatly appreciated!

     << Brian >>

barrett2@ohstpy.mps.ohio-state.edu (05/12/89)

> ...
> slightly more prosaic wording), fork over ~$300, pop open my Mac SE, swap
> two of the existing chips with the two new 1M (each, right?) things, and
> seal the whole tamale up again, and I'll have a 2.5M Macintosh on my hands?

Close.

First, a SIMM in not a ckip, but a small card with 8 chips (MAC) or 9 (IBM)

Second, 'opening your Mac will void your warranty'.  This does not really 
bother me, since most of us are no longer under warranty.  However, opening 
a Mac (I've cracked mine twice) is not a job to be taken lightly.

Third, the SIMM sockets are in pairs, so that you must be sure to use the 
correct sockets.

Fourth, you must remove a resistor (I believe I heard they had changed it 
to a jumper in later models, but I'm unsure of this point).  I believe the 
necessary information can be found in Tech Note 176 (comp.binaries.mac or 
sumex-aim in the tech directory).

> Does anyone know of any better offers on memory chips?
> 
> Should I buy now, or hope that the prices will drop further?

Since I don't receive MacWeek, I'd like a phone number for Technology Works 
(since no one seems to have posted it yet).

> And what, precisely, are DRAM chips, and are they a feasible (and cheap!)
> option?

Dynamic Random Access Memory.  As opposed to Read Only Memory (ROM, which 
can be programmed once be our beloved Apple) and Static RAM.  Dynamic RAM 
chips require the circuit to "refresh" the contents periodically (kind of 
like reviewing material for a test) while static do not.  This diffenence 
should not bother you.

> Any explanations to clear this up would be greatly appreciated!
> 
>      << Brian >>

I hope this helps.
- Tom Barrett (Ohio State University)
any errors are my own ignorance

corrie@serss0.fiu.edu (Corrie) (06/15/90)

   Well, much has been said about where to get cheap SIMMs - The CHIP MERCHANT -
but how to install them is yet another matter.  The CHIP Merchant sends no
installation instructions.   That is where keeping back issues of your favorite
computer magazine come in handy.
   In the February 1989 issue of MacUser there is an article entitled 
'The  Persistence of Memory' on page 140.
   The article explains how to make the upgrade very well, but 
not how to open up the Mac+, or SE.   Well, you need a 9 inch allen wrench
which can be obtained from Mac Connection for $8.00.
   The other small problem is that, no matter what your upgrade is, you must
move around a resistor on the mother board which may require soldering.
If your upgrade is for more than 2 Megs, then you can just cut loose
the resistor since for that configuration it must be removed anyway.

corrie@fiu.edu  (internet)
corrie@servax   (bitnet)

*** I speak only for myself... No one else has my mind - to do otherwise. ***

rang@cs.wisc.edu (Anton Rang) (06/15/90)

In article <864@kluge.fiu.edu> corrie@serss0.fiu.edu (Corrie) writes:
>   The other small problem is that, no matter what your upgrade is, you must
>move around a resistor on the mother board which may require soldering.
>If your upgrade is for more than 2 Megs, then you can just cut loose
>the resistor since for that configuration it must be removed anyway.

  Resistors are only found on the older systems; newer ones have
jumpers instead, so that you don't actually have to cut anything.
There is a technote which covers all the different memory
configurations pretty well.

	Anton
   
+---------------------------+------------------+-------------+
| Anton Rang (grad student) | rang@cs.wisc.edu | UW--Madison |
+---------------------------+------------------+-------------+

gillies@p.cs.uiuc.edu (06/27/90)

Because, for $8 you can get a TORX screwdriver set at Sears or Kmart
and do it yourself in less time than it takes to say, "Where's the
nearest macintosh dealer?"

jeff@eniac.seas.upenn.edu (Jeff White) (06/28/90)

In article <126900200@p.cs.uiuc.edu> gillies@p.cs.uiuc.edu writes:
>
>Because, for $8 you can get a TORX screwdriver set at Sears or Kmart
>and do it yourself in less time than it takes to say, "Where's the
>nearest macintosh dealer?"

  Actually, they cost more like $3 or $4, but they WILL NOT work.  The 
standard screwdriver length is too short to reach to get the screws at the 
top cover, and a torx socket adapter is too wide.  

						Jeff White
						jeff@eniac.seas.upenn.edu