Subject: Re: Questions
To: None <port-mac68k@NetBSD.ORG>
From: David G Taylor <taylord@ecn.purdue.edu>
List: port-mac68k
Date: 10/16/1997 11:09:33
>Paul Goyette wrote:
>>
>> Hmmm.  I've got 80MB in my IIci, but both NetBSD and MacOS only recognize
>> the first 64MB.  Maybe I should switch the 16MB SIMMS and 4MB SIMMS into
>> the opposite memory banks?
>>
[snip]>
>Hmmmm....that's kinda weird.  In general, from what I've read, you're
>supposed to have the larger SIMM's in Bank A (the one closer to the
>hard drive, I believe), although this was mainly back when people had a
>lot less memory.  Are you using internal video, or do you have a card?
>If the former, perhaps you're getting some weird mapping problems since
>internal video uses part of Bank A memory.  What speed are you SIMM's?
>(not that this should really matter...)
>
>At any rate, you can always switch the two banks and see (it's not like
>you'll hurt anything unless you statically zap the memory).  And if this
>doesn't work, I'll volunteer to take the extra 16MB off your hands ;-)
>
[snip]
On the contrary, in the days when Apple wanted $196 for a 1 MB SIMM, you
put the 4x 256k in bank A to support the onboard video, and the 4x 1MB in
bank B to support OS. This is covered in a note somewhere in IM, first
edition.  There was a noticeable speed up with this arrangement. This may
lead to a net slowdown with large SIMM units AND onboard video in use
together, since you force shared  memory use between video and OS, and
video wins to yield glitchless video. I've no experience with > 32 MB on a
IIci, but it would be worth knowing if the IIci can see beyond 64 MB with
standard simms.

----
73 de David KB9KNS                (Am cordless; will travel.)
--taylord@ecn.purdue.edu