Here is information about your memory.
128 MB RAM PC100
512 MB (2 x 256 MB DIMM)
100 MHz synchronous
Two - 168-pin DIMMs
32, 64, 128 and 256 MB DIMMs
SDRAM, Intel PC SDRAM unbuffered DIMM specification, revision 1.0 compliant
Make sure its SDRAM DIMM PC100. I dont know if your computer fully accpets PC133. Just get PC100 and you will be fine.
Finished With TF.