Subject: Re: stability?
To: Charles Sprickman <spork@inch.com>
From: Colin Wood <cwood@ichips.intel.com>
List: port-mac68k
Date: 08/06/1997 17:28:27
Charles Sprickman wrote:

> While I'm posting, does anyone have recommendations on memory?  I'd like
> to bring it to 16M, but the variety of 30-pin simms is confusing me...
> Any suggestions on a vendor knowledgeable about old Macs?

You can check out Newer Technology's page for info on their GURU program.
GURU contains a lot of info on what kind of memory different Mac's
require, although I wouldn't buy from them since I think that memory.net
is probably a lot cheaper on RAM.  Ok, I just checked and it's not
memory.net anymore, here's the proper URL:

http://www.syzygyelectronics.com

As for what a IIx needs as far as RAM goes, here's what I figure you've
got:

8 30-pin SIMM slots, in 2 banks (A and B)

In one bank, you've got 4 256kB SIMM's.  In the other, 4 1MB SIMM's.

Both sets of SIMM's are probably 100ns or so, I don't think the IIx
required anything faster.

Correct so far?

Well, to get 16MB, there might be a couple of ways to go, both of them
involve buying all new chips :-(  Since 30-pin SIMM's have to be replaced
4 at a time (they're 8-bit chips, 4x8 = 32-bit data path), you can either
buy 4 4MB SIMM's and put them in the bank where the 256kB SIMM's are and
then pull the 1MB SIMM's (you said you only wanted 16MB, right? ;-), or
you can get 8 2MB SIMM's (assuming that they even make them for your
machine, and I think that they do).

Make sure that the SIMM's you get are at least as fast as recommended by
_some_ RAM guide for your machine.  Also, you probably shouldn't bother
going too much faster than this recommendation, since many machines can't
make good use of faster SIMM's :-(  Keep in mind that you should never mix
different speed SIMM's in the same bank (it might cause nasty memory
errors).  Also, don't buy parity SIMM's, since I think that only a few
models of the IIci and effectively use them.


> And is there any way to make a Mac automatically power up after a power
> failure?

Unfortunately, I don't think that there's an easy way to do this with a
IIx.  The IIcx does support this feature (it was the first Mac to do so,
IIRC).  There might be some external hardware you can buy to perform this
function, tho.

I hope that this helps some.

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
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I speak only on my own behalf, not for my employer.