cjp@ursaco.beartrack.com (cjp login) (02/19/91)
Newsgroups: comp.sys.3b2 Subject: Upgrade of memory on 0.5 meg 7300 I have received the following notes on the upgrade of the memory on the mother board of a 7300 with only 0.5 megs of memory. First locate the jumpers at JR1. You will find E2 connected to E3 on the bottom of the board. You will have to remove the motherboard and cut this jumper. Next carefully install a jumper from E1 to E2 on either side of the board. Then install a 74F258 chip in the spare near the jumpers described above. Remove all of the memory chips and replace with them 256K bit 150ns DRAMS. This sounds pretty easy if you have any experience with working on printed circuit boards. Has anyone done it? What problems should I look for? I expect to use sockets for the 256k chips and the 74F258. -- cj
mvadh@cbnews.att.com (andrew.d.hay) (02/19/91)
In article <1991Feb19.033445.6107@ursaco.beartrack.com> cjp@ursaco.beartrack.com (cjp login) writes:
[]
"Then install a 74F258 chip in the spare near the jumpers described above.
"
"Remove all of the memory chips and replace with them 256K bit 150ns DRAMS.
"
"This sounds pretty easy if you have any experience with working on printed
"circuit boards. Has anyone done it? What problems should I look for?
"I expect to use sockets for the 256k chips and the 74F258.
here's a trick i have used with *phenominal* success: after sucking
the solder from a hole, wiggle the leg of the chip WITH THE SOLDERING
IRON! you will usually hear a click as the solder, wicked in between
the leg and the side of the hole, breaks loose under the combined heat
and force of the iron. don't use too much pressure; let the iron do
its work. after this, the chip will just about *fall* out, and the
hole will be unaffected.
i wouldn't bother with a socket for the 258.
--
Andrew Hay +------------------------------------------------------+
Ragged Individualist | JAAAAAAANE! |
AT&T-BL Ward Hill MA | HOW DO YOU STOP THIS CRAZY THING? |
a.d.hay@att.com +------------------------------------------------------+