Norma's  post (clipped)

<<< I have 256 and can only go to 512, can I use :


pqi POWER Series 256MB 184-Pin DDR SDRAM System Memory?>>>


I am sorry  NO  is the answer. the reason is DDR means dual  data  rate and so 256 mb DDR means total of 2x256=512 and you alrady have 256 mb. so you can upgrade only to 128mb DDR.

CAUTION:----

From HP site I find that your model HP 521N HAS ONLY PLAIN SDRAM AND NOT DDR

THEREFORE YOU CAN NOT USE ANY DDR IN THIS MODEL.

<<< my manual says PC800 and this is PC3200, does this matter?>>>

I am not able to understand this because the HP site shows the "speed" of the memory in your model as PC-133

perhaps you would care to recheck the specs. for your model at HP WEB SITE.

HTH AND GOOD DAY-----Venkat Viswanatnan

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