Trouble is that Crucial's 2x256Mb PC133 RAM is ~£90 and their equivalent PC100 RAM is substantially so much higher that it's cheaper to buy a another C600 laptop with 512Mb RAM in it!
On the other hand, my Laptop came with Samsung PC133 RAM in it from new and it's much, much cheaper to buy Samsung RAM, particularly off eBay.
Does anyone know what Samsung's codes are? As I said, I bought two new sticks of M464S3254ETS-L7A for £30 (now refunded) to replace my single stick of Samsung 128Mb RAM, M464S1724DTS-L7A, both PC133S-333-542.
Seems that L7A can be changed for L1H, L75 etc and I think is to do with speed, whereas the DTS can become ETS, CTS,CT2, CT1 etc and I haven't a clue what they denote!
Only other thing I can do is buy an identical 128Mb stick and settle for 256Mb total!