2GB Memory RAM Upgrade for the Lenovo Thinkpad R61 Series, T60 Series, T61 Series, X60 Series and X61 Series Laptops (DDR2-667, PC2-5300, SODIMM) at Amazon.com
A-Tech 8GB (2 x 4GB) RAM for Lenovo THINKPAD T61P | DDR2 667MHz SODIMM PC2-5300 200-Pin Non-ECC Memory Upgrade Kit at Amazon.com
Lenovo Thinkpad Laptop (2000s): 2 listings
I “think” you enjoy this… T61 (256 Gb SSD Debian 10, RAM 4 Gb) and E14 2021 (upgrade with RAM 16 Gb, 1 Tb M.2 for Windows 11 and 256 Gb SSD for Debian 11, all Crucial) : r/thinkpad
Lenovo ThinkPad T400s Core 2 Duo 2.40GHz 8GB RAM 320GB HDD Windows 10 Pro – ASA College: Florida