IBM THINKPAD S05L-1270-01 - Manual (Page 218)

Memory Checkout
DIMMs are available for increasing memory capacity.
Note: Models 760XL and 760XD have a dip switch on the
DIMM adapter card. When a 64 MB 2bank DIMM
is installed, the dip switch is located to the left as
case 2, and the base memory (8 MB) on the DIMM
adapter card is disabled.
The 64MB 2 bank DIMM is accepted only in slot 2.
If the card is installed in slot 1, the card will not be
recognized as 64MB DIMM.
206 IBM Mobile Systems HMM