The RAM is from hp omnibook 500. Can it work?

Please provide your memory's data (marked on the face). hp omnibook 500 may use PC100 memory. T23 requires PC133.

If it's PC133 it still may not work as IBM's can be picky sometimes over the type of RAM they will work with. Chances are though, if it is PC133, it work just fine.

According to the experts here, T23's are less picky about memory than other Thinkpads. Search the posts here for "T23 memory"

then, can I install other brand (like kingmax or kingston) RAM to it?

Yes, you can choose kingston, kingmax, toshiba, such as brand memory with PC133 chipsets on T23.

T23 owners agree, I take it, that the T23 is not so narrow about memory upgrade PC133 module chips, as high price RAM sellers (like Crucial & Memory Giant) claim?

I have two 128MBs in board. I'd like to upgrade to at least 512MB but would like to get new. Reseller's want about $100 for two used 256MB modules (supposedly) pulled from T23s.

Does anyone know if I can mix a major brand 512MB with a IBM 128MB and will the PNY PC133, 512MB work that TigerDirect.com sells (recommends) near its reburbished T23 ads?

You can mix 128MB PC133 and 512MB PC133 on T23 (i did it now)/

It should. I've always had good luck with PNY ram.

[/quote]It should. I've always had good luck with PNY ram.[/quote]

Thank you for your advice. I bought the PNY 512MB 'RAM' module indicated for my T23 2647. I received it Monday and installed it. Works like a charm. My previously 256MB T23 races off and online now!

--Bruised