🚀 go-pugleaf

Mac SEs had 2 versions of setting memory - resistors or jumper pins. These
have to be set according to the total memory installed. In addition, my
old SE memory instructions state that SIMMs must be installed in pairs,
and it may make a difference whether slots 1-2 are used versus slots 3-4. 

An SE with resistor selection will have an area on the PC board marked
"R35 - R36" with the words "256K bit" above R35 and the words "one row"
below R36. The resistor is installed in the R35 position for 1MB (4 each
256K SIMMs); for 2MB the resistor is moved to position R36; 2.5 MB and 4MB
requires NO resistor in either position.

If you have a jumper model SE, there are 3 pins and one jumper; the jumper
connects pins 2/3 for 1 MB, pins 1/2 for 2 MB, and is removed for 2.5 and
4 MB.  

I cannot recall if some 30 pin SIMMs would not work even if they fit.



In article <34e98cf9.2995073@news.demon.co.uk>,
Steve Parry <spug@banspamintlog.demon.co.uk> wrote:
>I have acquired a (very) old Mac, it is a Macintosh SE 
>(model No M5011). It is an all in one unit with two floppies and a
>hard drive. It starts to boot ok, smiley face and all, the face then
>turns to a grumpy one and an error code is given (I don't have it to
>hand ATM). Opening the case, I found it had 2x 1Mb 30 pin Apple
>SIMMS(bank 3 & 4) and 2x 1Mb standard 30 pin (ie PC type) SIMMs (banks
>1 &2). Can these old Mac's use STD 30 pin SIMMS, Can they be mixed
>like this?
>If I take out the STD 30 pins and leave just the Apple SIMMS the
>machine stops booting at a much earlier stage, the error message is
>already there as soon as the screen warms up enough to read, in fact.
>Do all four banks HAVE to be fully populated for a sucessful boot?
>
>I am not at all familiar with Macs, new or old, so any and all info
>would be warmly appreciated,
>Thanks......
>
>----------------------------------------------------------------------
>XXXXXXXXXX-------Sparrow (Spug) in London UK.--------XXXXXXXXXXXXXXXXX
>xxxxxxxxxx---Remove "banspam" from address to reply----xxxxxxxxxxxxxxx


-- 
-----------------------------------------------------------
Gary Louie/Staff Audio Engineer
Univ. of Washington/School of Music/Seattle, Washington USA
louie@u.washington.edu