It uses PC100 memory. My parents have a Emachines 600is that I bought for them at Christmas (with their money). At 32MB of SDRAM, the machine crawled. Upgraded to 128MB and it ran fine. Since memory is so cheap, they wanted the memory maxed out. I recently upgraded it again for them to 256MB total. The first stick I bought from Crucial using the 15% webpromo for $65. Then I bought the second stick for $56. Now it is at $50. What a great time to buy SDRAM!
Crucial 15% off
The only problem with the machine is that the CD drive broke. I replaced it with a Creative CD drive and it does not work either. Grrrrr. I am still troubleshooting this problem. The Emachines CD really is broke as it will not work on my machine. I have not tried the Creative one out yet. Emachines said that they would replace the CD drive, but you had to send in the entire machine, pay shipping both ways, and you would not see your machine for 4 weeks. What a ripoff, but I should have expected it for $400.