Subject: Re: stability?
To: Colin Wood <cwood@ichips.intel.com>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 08/06/1997 17:19:48
> 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?
> 
[vendor suggestion]
> 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.

On the "don't buy" suggestions above, I'd change it to, "don't pay extra."
For instance, if parity SIMMs are on sale, go for them. You won't use
the parity part, but it'll be fine. Just don't pay extra. Also, for the
speed, for 72 pin SIMMs (which aren't what you want here), a number of
the vendors around here (Fry's at least) have discontinued everything but
60ns. So if 60 is the cheepest, I'd say go for it, even though you only
need 100ns.

> > 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.

You're right that the II didn't do it, but I thought the IIcx and IIx came
out at the same time. So I'd (potentially incorrectly) expect the IIx to
do it also. Weird.

On macs which automatically support it, you just push the power button in
back in, and turn it 90 degrees, say with a dime or a screw driver. If the
power button on the IIx has such a slot, it'll auto-reboot. Though NetBSD
mightn't be too happy.

Take care,

Bill