Since I was the "private email" source Wonko referred to this is not
independent confirmation, but I'm pretty sure of myself on these points.

At 12:35 PM -0800 11/16/99, Greg Dunn wrote:
>"David A. Gatwood said:"
>>
>> IIRC, the PAL chip was only necessary (only available) for one particular
>> size of memory.  I think that was 4 megs, but I'm probably remembering
>> wrong.  Whether it's necessary on the IIx or not, I'm not sure.  I think
>> NewerTech or someone has a memory guide that should list those machines.
>> Do a web search for memory guide mac, say on google (www.google.com).
>
>I'm pretty sure only the II required PALs; the IIx motherboard was designed
>to accept standard 4MB SIMMs.

I do not know of anyone trying larger than 4MB SIMMs in an original II.
The point about 4Mb chips being the problem even if it was a 1MB SIMM was
well made.  The problem is that there was a test mode invented for the 4Mb
chips which the original II motherboard design did not know it needed to
avoid;  hence random crashes.  My IIcx does not have the problem, and the
IIx and SE/30 were all similar vintage.

>> AFAIK, no macs require parity SIMMS, but the extra (ninth) bit won't hurt
>> anything.
>
>I have been using 9-bit SIMMs in IIx/IIcx/IIci machines for a couple of years
>now, with excellent results.  They are frequently cheaper than the Mac-only
>SIMMs, due to volume; a pleasant bonus!


The IIfx used parity.  Some models of IIci used parity, but most models
made did not have it because it was more expensive.  Not sure about
Q900/Q950.  I think all other models did not.

My experience:  putting parity SIMMs from a Sun into an SE/30 was no
problem.  There have been reports on this list in the past that you cannot
count on this universally.  I suspect that if the SIMMs are fast enough it
shouldn't be an issue.

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