[comp.sys.mac.hardware] IIsi memory upgrade questions...

kevinb@wrc.unr.edu (Kevin Brewer) (11/02/90)

I have stumped the local dealer with these questions, but I am sure
that they can be answered here - I don't recall them being discussed
before (forgive me if they have).... 

I will soon (standard 4-8 week educational purchasing delay) be a _very_
proud owner of a IIsi (with Apple 13" RGB). I will be getting it with
2Meg RAM - which I know will not be enough for real(tm) work.
The questions:

  If I upgrade it to 17Meg, will the MacOS (v6.0.7?) not have a fit?
  How much memory will the MacOS let me use? 17Meg!!? 
  What about those 2Meg SIMMS - do they exist? - how much $?

Thanks - KEVIN
kevinb@wheeler.wrc.unr.edu
Kevin Brewer
kevinb@wheeler.wrc.unr.edu
  "When water chokes you, what are you to drink to wash it down?" -Aristotle

schneide@parc.xerox.com (Kris A. Schneider) (04/04/91)

Hi folks,

Another in the long line of memory upgrade notes...

My si's currently got 2M (1M static + 4*256K SIMMs).  Now, my understanding
is that as long as the memory speeds are fast enough (90 or 100ns I think),
I can mix'n match pretty much as I please.  So, my question is, if I plan
on purchasing an additional 4M of memory, why wouldn't I just get a single
4M SIMM instead of 4*1M SIMMs?  Seems to me I'd end up with an additional
768K of memory onboard instead of collecting dust somewhere.  Although I
haven't been pricing, it would also seem that a single 4M SIMM would be
cheaper than 4*1M SIMMs, no?  Oh well, someone please set me straight!

Oh, before I let you go, let me pose the popular follow-up:  where have
folks been getting the best price/quality/service on memory upgrades?

Thanks much!

-Kris
schneide@arisia.xerox.com

strange@sprite.berkeley.edu (Steve Strange) (04/04/91)

In article <1991Apr3.234333.4056@parc.xerox.com> schneide@parc.xerox.com (Kris A. Schneider) writes:
>
>Hi folks,
>
>Another in the long line of memory upgrade notes...
>
>My si's currently got 2M (1M static + 4*256K SIMMs).  Now, my understanding
>is that as long as the memory speeds are fast enough (90 or 100ns I think),
>I can mix'n match pretty much as I please.  So, my question is, if I plan
>on purchasing an additional 4M of memory, why wouldn't I just get a single
>4M SIMM instead of 4*1M SIMMs?  Seems to me I'd end up with an additional
>768K of memory onboard instead of collecting dust somewhere.  Although I
>haven't been pricing, it would also seem that a single 4M SIMM would be
>cheaper than 4*1M SIMMs, no?  Oh well, someone please set me straight!
>
All four SIMM slots must have the same size SIMM in the IIsi.  This is
due to the way memory is interleaved - all slots are in the same bank.
I do not believe you can use just one SIMM.

	Steve

james@netcom.COM (James L. Paul) (04/04/91)

In article <1991Apr3.234333.4056@parc.xerox.com> schneide@parc.xerox.com (Kris A. Schneider) writes:
>
>Hi folks,
>
>Another in the long line of memory upgrade notes...
>
>My si's currently got 2M (1M static + 4*256K SIMMs).  Now, my understanding
>is that as long as the memory speeds are fast enough (90 or 100ns I think),
>I can mix'n match pretty much as I please.  So, my question is, if I plan
>on purchasing an additional 4M of memory, why wouldn't I just get a single
>4M SIMM instead of 4*1M SIMMs?  Seems to me I'd end up with an additional
>768K of memory onboard instead of collecting dust somewhere.  Although I
>haven't been pricing, it would also seem that a single 4M SIMM would be
>cheaper than 4*1M SIMMs, no?  Oh well, someone please set me straight!
>
>Oh, before I let you go, let me pose the popular follow-up:  where have
>folks been getting the best price/quality/service on memory upgrades?
>
>Thanks much!
>
>-Kris
>schneide@arisia.xerox.com

The IIsi has 2 banks of ram. One bank is soldered to the main board and is
not removable. This bank is 1 megabyte, and is also used to store the video
image.

Bank 2 (or B) consists of 4 SIMM slots. GOLDEN RULE: ALL SIMMs IN A BANK MUST
BE THE SAME DENSITY. You always change memory configurations on a bank level.

Because the IIsi only has one bank, this limits flexibility somewhat. You can
only change the SIMMs in bank B. Because the bank has 4 slots, you must change
memory in groups of 4 SIMMs. Here are the possible combinations:

1  Meg system: Bank A: 1 Meg (soldered)    Bank B: Empty
2  Meg system: Bank A: 1 Meg (soldered)    Bank B: Four 256K SIMMs
3  Meg system: Bank A: 1 Meg (soldered)    Bank B: Four 512K SIMMs
5  Meg system: Bank A: 1 Meg (soldered)    Bank B: Four 1M SIMMs
9  Meg system: Bank A: 1 Meg (soldered)    Bank B: Four 2M SIMMs
17 Meg system: Bank A: 1 Meg (soldered)    Bank B: Four 4M SIMMs

Once again, you cannot mix and match densities in a single bank, which
you only have one of in the IIsi that can be changed. So, whenever you
change your memory configuration, you have to remove ALL the old SIMMs
and either put them into another mac, sell them, or put them on dusting duty.

BTW, the 2 meg SIMMs are made just like 4 meg SIMMs, but with half the chips,
and the 512K SIMMS are made just like the 1 meg SIMMs, but with half the chips.

Thanks for the memories...

-- 
James L. Paul

Internet:  netcom!james@apple.com | AppleLink: D1231 | CompuServe: 72767,3436
UUCP: {apple,amdahl}!netcom!james | GEnie:    J.PAUL | Voice:    415 377-1981
Packet:     N6SIW@N6EEG.CA.USA.NA | Delphi:   JLPaul | Home Fax: 415 377-0381

tgoose@eng.umd.edu (Jason Garms) (04/05/91)

In article <1991Apr3.234333.4056@parc.xerox.com>, schneide@parc.xerox.com (Kris A. Schneider) writes:
 
> My si's currently got 2M (1M static + 4*256K SIMMs). 
Your IIsi does not have static RAM.  I think there is a confusion in terms.  Static RAM refers to RAM which is high speed (typically below 30ns) and consumes very little power.  This RAM is also very expensive.  What is in your machine is standard RAM (DRAM).  The confusion may be because this is soldered onto your logic board. (I guess and is therefore static ;->)

> Now, my understanding
> is that as long as the memory speeds are fast enough (90 or 100ns I think),
> I can mix'n match pretty much as I please.  So, my question is, if I plan
> on purchasing an additional 4M of memory, why wouldn't I just get a single
> 4M SIMM instead of 4*1M SIMMs?  Seems to me I'd end up with an additional
> 768K of memory onboard instead of collecting dust somewhere.  Although I
> haven't been pricing, it would also seem that a single 4M SIMM would be
> cheaper than 4*1M SIMMs, no?  Oh well, someone please set me straight!
NO, you cannot mix and match as you please.  Because of the way memory is addressed(on the Mac II models), it must be installed in banks of 4!  There are four slot inside your machine(which currently have 256k SIMMs in them).  Thus your upgrade options would be as follows:
	Remove the four 256k SIMMs and install:
		four 1MB SIMMs for a total of 5MB
		four 2MB SIMMs for a total of 9MB
		four 4MB SIMMs for a total of 17MB

no matter what you choose, the four 256k SIMMs become fairly worthless.

Jason Garms
tgoose@eng.umd.edu

P.S> The 256k SIMMs make nifty keychains and around Christmas time, put a hook on them and hang them on a tree!!! 8-)

edgar@function.mps.ohio-state.edu (Gerald Edgar) (04/05/91)

>		four 1MB SIMMs for a total of 5MB
>		four 2MB SIMMs for a total of 9MB
>		four 4MB SIMMs for a total of 17MB
The IIsi delivered to us recently had four 512K SIMMs, for a total
of 3MB.

By the way, can a Mac IIci (for example) use 512K SIMMs?

--
  Gerald A. Edgar          
  Department of Mathematics             Bitnet:    EDGAR@OHSTPY
  The Ohio State University             Internet:  edgar@mps.ohio-state.edu
  Columbus, OH 43210   ...!{att,pyramid}!osu-cis!shape.mps.ohio-state.edu!edgar

josh@athena.mit.edu (Josh Hartmann) (04/05/91)

In article <1991Apr5.140313.12667@zaphod.mps.ohio-state.edu>, edgar@function.mps.ohio-state.edu (Gerald Edgar) writes:
|> >		four 1MB SIMMs for a total of 5MB
|> >		four 2MB SIMMs for a total of 9MB
|> >		four 4MB SIMMs for a total of 17MB
|> The IIsi delivered to us recently had four 512K SIMMs, for a total
|> of 3MB.
|> 
|> By the way, can a Mac IIci (for example) use 512K SIMMs?

Yes.

The ci and the si are the only Mac IIs that can take 512K SIMMs. I am not
sure if the LC can.

-- 

Josh Hartmann             |     ___   ___     | ``the imagination is like an
josh@athena.mit.edu       |    |   | |   |    | engine that can work on many
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