Ref: 00420006
Title: Upgrading 3C505 to 384 KB Memory on New Layout (Assy 2012-10)
Date: 5/10/91

Copyright 3Com Corporation, 1991.  All rights reserved.

On the latest rev of the 3C505 board, there is the new layout of the memory
area.  (To identify the latest rev of the board, look for "Assy 2012-10" on
the component side of the adapter along the top or side edge.)  The
standard socketed memory chips are no longer intermixed with the empty chip
sockets for add-on memory.  Instead, there is one bank of soldered memory
chips and one bank of empty sockets to add memory on the board.   As you look
at the component side of the adapter, with the slot bracket to the right, the
leftmost column of sockets is for RAM upgrades.  The column to the right is
the standard 256 KB RAM.

  *  To add 256 KB of memory (totaling 512 KB), just fill up all of the empty
sockets.

  *  To add 128 KB (totaling 384 KB), start at the bottom of the board with
the socket marked "A" and install the chips in every other socket.  When done
you will have memory chips in socket A, C, E, and G.

Caution:  Install the RAM chips oriented with their notches in the same
position as on the preinstalled RAM chips.  Otherwise, the RAM or the adapter
may have to be replaced.

