Upgrading the CPU in ThinkPad X61 — Wenting's Web Page
My new beast : thinkpad X61S 3GB ram : r/thinkpad
CMS 2GB (1X2GB) DDR2 5300 667MHZ NON ECC SODIMM Memory Ram Upgrade Compatible with Ibm Lenovo® Thinkpad X61 Notebook Ddr2 Pc5300 Sodimm - A38 System Specific Memory - Newegg.com
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) - Walmart.com
4GB 2X2GB Memory RAM for Lenovo ThinkPad X Series X61 (7674ES7) 200pin 667MHz PC2-5300 DDR2 SO-DIMM Black Diamond Memory Module Upgrade System Specific Memory - Newegg.com
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