Tim,
I bought 1 GB DIMM for my Tyros 3 last week on ebay from Sean Fournier. $49.95 plus shipping. Received them in four days. They fit right in and work fine.
http://cgi.ebay.com/1GB-YAMAHA-Motif-ES-XS-TYROS3-TYROS-3-RAM-MEMORY-NEW-1G_W0QQitemZ220332195078QQihZ012QQcategoryZ14913QQcmdZViewItemQQ_trksidZp3286.m7QQ_trkparmsZalgo%3DLVI%26it u%3DUCI%26otn%3D2%26ps%3D5

I may have paid a little more as they are advertised specifically for Tyros3. I found others advertised and inquired about compatability and was told that the those C133 168 pin DIMM were not for the Yamaha keyboards.

Jay R

[This message has been edited by JR in TX (edited 08-17-2009).]

[This message has been edited by JR in TX (edited 08-17-2009).]

[This message has been edited by JR in TX (edited 08-17-2009).]