IBM Personal Computer XT Manual To Operations page 236

Extender Card Switches
Set the switches on the Extender Card to reflect total
system memory.
Extender Card Switch Settings
1 2 3 4 1 2 3 4
16Kt064K
352K to 384K
~UUU~ ~U~~u
1 2 3 4
1 2 3 4
96Kto 128K 416K to 448K
~~~~~ ~~~~~
1 2 3 4
1 2 3 4
160K to 192K 480K to 512K
~~~~~
~~UU~
1 2 3 4
1 2 3 4
224K to 256K
544K to 576K
~~~~~
~UU~
1 2 3 4
1 2 3 4
288K to 320K 608K to 640K
~~~~~
~.~~~~
4-22 Switch Settings