jmpiazza@cs.Buffalo.EDU (Joseph M. Piazza) (03/27/89)
I'm having a small crisis. I believe I erroneously clipped resistor 35
when performing a memory upgrade to 2.5 Meg.
I was making 2 Meg upgrades to four of our department's Macs. The last
machine was a recently acquired SE with two floppy drives. The SIMM sockets
were a light biege -- first time I've seen that. Upon powering the sucker
up the screen quickly came up with a checker board pattern with the flashing
question mark on the floppy image. Normally it takes a while to perform
memory test. Drats! I forgot to clip the resistor 35(?) as required. I
open it up, clipped the resistor and ...
Same thing. Upon closer inspection of the board I noticed that there
is a jumper where I don't remember seeing before. Has Apple gone ahead
and revised the board by using a jumper instead of clipping a resistor?
(Without telling me? :-) If so, how should it be properly set for 2.5
Meg? If not, any ideas as to what is wrong and how to fix it?
As it turns out it's the department chairman's Mac, wouldn't you
know? :-(
Please respond via e-mail. I will summarize and post.
Thanks,
joe piazza
--- Cogito ergo equus sum.
CS Dept. SUNY at Buffalo 14260
UUCP: ..!{ames,boulder,decvax,rutgers}!sunybcs!jmpiazza GEnie: jmpiazza
BITNET: jmpiazza@sunybcs.BITNET Internet: jmpiazza@cs.Buffalo.edujmpiazza@sunybcs.uucp (Joseph M. Piazza) (04/01/89)
In article <4916@cs.Buffalo.EDU> jmpiazza@cs.Buffalo.EDU (that's me!) writes: > I'm having a small crisis. I believe I erroneously clipped resistor 35 >when performing a memory upgrade to 2.5 Meg. > > ... Upon closer inspection of the board I noticed that there >is a jumper where I don't remember seeing before. Has Apple gone ahead >and revised the board by using a jumper instead of clipping a resistor? >(Without telling me? :-) If so, how should it be properly set for 2.5 Meg? (This is on an SE, by the way). Here's the story as succintly written by Mark Johnson <mjohnson@Apple.com>: [All newer model SEs have a jumper installed to change memory. This change [is documented in Macintosh Technical Note #176, latest revision February 1989. [Repair or replace the resistor you cut, and check out this Note for your [proper configuration. For 2.5MB, you should remove the jumper altogether. and from Boy Thomas <tboyd@csm9a>: [... Also, install the 1 meg simms in the TOP two sockets instead of [the bottom two. For all the info Ric Anderson <ric@arizona.edu> directs us to: [Get a copy of TN176. It has the info for both jumpers and ["cut-the-resistor" SE's, as well as other systems. I think [it's found on sumex-aim.stanford.edu via [ ftp> cd info-mac/tn [ ftp> get tns-feb89-part1.hqx [ ftp> get tns-feb89-part2.hqx [ ftp> get tns-feb89-part3.hqx [ [This group has the updated tn176 which is a folder with a MacWrite [instruction document, and some MacDraw pictures of boards. Also, thanks to Howard Haruo Fukuda <hf07+@andrew.cmu.edu>: [... As far as the resistor is concerned, it's not too much of a big [deal if you cut it close to the motherboard like you're supposed to. Just a [little resoldering. If you didn't... Well, I guess I did 'cause our hardware guru fixed it up so well I could hardly notice it. The Mac is up and running with 2.5 Meg of memory. Thanks all, joe piazza --- In capitalism, man exploits man. In communism, it's the other way around. CS Dept. SUNY at Buffalo 14260 UUCP: ..!{ames,boulder,decvax,rutgers}!sunybcs!jmpiazza GEnie:jmpiazza BITNET: jmpiazza@sunybcs.BITNET Internet: jmpiazza@cs.Buffalo.edu