Finding out what type of ram chip this is

I have 2 cache chips on a cd-rw that I want to try to replace, and I'm hoping some how I can find a replacement somewhere.

The chips say
"SEC KOREA 939
MK48C2100CK-5"

The sec means it's made by samsung, I'm guessing the C2 part have somthing to do with cas latency, and maybe the ck-5 part has to do with the speed. Does anyone know how to find out what type of chip this is? I believe it is 2 meg chip, that's all I know. Is there a place I can find bare chips from? I'm thinking if I can find out some info on the chip maybe I can rip one off something.

They are both 2 meg chips made by samsung. Do you think it is possible to rip off 2 similar chips off a 16 meg stick with 8 chips on it? I might try that, I can probally find a stick of ram off ebay very cheap.