I got an iMac g3 450 mhz (summer 2000 i think) and i want to upgrade its memory. I know i need PC 100/133 168 pin . I already got one 512mb from amazon with those specs although it didn't work. For some reason all the memories that say they are compatible with mac are x3/4 the price of the rest of same technology. Any suggestions as to where I should look for memory or any spec I should be looking for in order for it to be compatible ?
Do not worry about getting one that is specifically "for iMacs." Any 168-pin PC 100/133 chip should fit just fine.
I have been working with several iMacs over the last few weeks. From my experience with them, a slot-loader seems to max out at around 1GB (two 512mb chips.)
If your RAM is not working, you likely got a bad chip. See if you can exchange it for another one.