Epson I+ - Manual (Page 54)

Jumper J2, Parity RAM
Parity RAM enables the computer to make sure that the data stored in
its memory is valid. The Equity I+ can support parity RAM to give you
added protection against loss of data. Installation of parity RAM is a simple
process, but you should ask your dealer to do it for you, as well as test the
RAM carefully. If you decide to install the parity RAM yourself, follow the
instructions below carefully.
You need to install four RAM chips. After you remove the cover of the
computer (see “Removing the Cover” in Chapter 3) locate sockets 6M, 6N,
7M, and 7N. See Figure A-2. Sockets 6M and 7M require 50256 or 51256
type (256KBitxl) h c ips; sockets 6N and 7N require 4164 (64KBitxl) chips.
When you insert the chips you must be absolutely certain that each one
is installed correctly, with the notch toward the back of the computer.
Once the chips are installed, locate jumper J2, as shown in Figure A-2.
To reach jumper J2 you need to remove the shielding over the power
supply by removing the two screws shown in the diagram below. Replace the
shielding after you move the jumper.
The factory setting for this jumper is position A. To enable the newly
installed parity RAM, J2 must be moved to position B.
If a fault occurs in the parity RAM, the computer displays a message
during the power-on diagnostics tests. You can continue work by adjusting
Jumper J2 to disable the parity RAM, but other errors may also occur, and
you should report the problem to your Epson dealer as soon as possible.
A-3