paisley@cme-durer.ARPA (Scott Paisley) (05/04/88)
About a month ago, my mac II 800K drive was operating very very
slowly. It worked but it would take 5 minutes to boot from the
floppy! This was a funky problem so I took it back to the dealer
and he promply replaced the entire mommy board. This was fine with
me and fixed the floppy problem.
NOW the memory question. On the old board the 8 simm slots were
labeled (Bank B) and (Bank A) from left to right (I think). The new
board is now labled SIMM1 SIMM2 SIMM3 SIMM4 from left to right, each
label covering 2 simm slots.
Can I use any memory configuration that I want as long as the 2 simm
slots have identical simms? (like the 2.5 MB configuration in Plus/SE)
(ie)
BANK (B) BANK (A)
SIMM1 SIMM2 SIMM3 SIMM4
----- ----- ----- -----
256 256 256 256 256 256 1024 1024 = 3.5 MB
rather than
BANK (B) BANK (A)
SIMM1 SIMM2 SIMM3 SIMM4
----- ----- ----- -----
256 256 256 256 1024 1024 1024 1024 = 5.0 MB
I sure think that this will work, but I wanted to ask around to see
if anyone else has done this, or if they have a simular mother board
labeled in this way.
Thanks for any/all ideas!
--
Scott Paisley ARPA : paisley@cme-durer.arpa (preferred)
BITNET : paisley@cmeamrf
"Why move around the world, when Eden is so Near."alibaba@ucscb.UCSC.EDU (Alexander M. Rosenberg) (05/04/88)
Apple specifies that each bank have identical SIMM types in them. I would suspect that the 1 meg SIMMS get treated like 256K SIMMS, and therefore won't work as well as you had hoped. ------------------------------------------------------------------------------- - Alexander M. Rosenberg - INTERNET: alibaba@ucscb.ucsc.edu - Yoyodyne - - Crown College, UCSC - UUCP:...!ucbvax!ucscc!ucscb!alibaba- Propulsion - - Santa Cruz, CA 95064 - BITNET:alibaba%ucscb@ucscc.BITNET - Systems - - (408) 426-8869 - Disclaimer: Nobody is my employer - :-) - - - so nobody cares what I say. - -
billkatt@caen.engin.umich.edu (Steven James Bollinger) (05/05/88)
> labeled (Bank B) and (Bank A) from left to right (I think). The new > board is now labled SIMM1 SIMM2 SIMM3 SIMM4 from left to right, each > label covering 2 simm slots. > > Can I use any memory configuration that I want as long as the 2 simm > slots have identical simms? (like the 2.5 MB configuration in Plus/SE) > > if anyone else has done this, or if they have a simular mother board > labeled in this way. > > Thanks for any/all ideas! Nope, you have to put the SIMMs in in Groups of 4. The Mac II is true 32-bit and so fetches from four SIMMs at once, therefore, all four must be the same. In short, SIMM1 & SIMM2 must be twins and SIMM3 & SIMM4 must be twins. Steve Bollinger (billkatt@caen.engin.umich.edu)