OK, to be more specific:
The eMacs with USB 1.1 and PC133 RAM are limited to 2 x PC133
--------------------------------------------------------------
700, 800 Mhz and 1 GHz
M8577LL/A; M8578LL/A; M8578LL/B; M8655LL/A; M8655LL/B; M8891LL/A; M8891X/A; M8892LL/A; M8892X/A; M8950LL/A; M8951LL/A; M8951LL/B; M9150LL/A; M9252LL/A
The eMacs with USB 2.0 and DDR RAM can go to 2 x 1 Gb PC2700 DIMMs
-----------------------------------------------------------------------
1 Ghz, 1,25 GHz and 1.42 GHz (despite the original Apple specification saying 2 x 512 as the max)
M9423LL/A; M9424LL/A; M9425J/A; M9425LL/A; M9461J/A; M9461LL/A; M9834LL/A; M9835LL/A; M99832; M99833; M99834; M99835
Notice there is an overlap in the 1 GHz models, so you really do have to check the specifics of the machine if you have a 1.0.
Thanks
Trevor
CanadaRAM.com