there are several versions of the PIII the original pIII's had 512k level 2 cache and a 100 mhz system bus, and had no letter. they were based on a .24 micron process that stopped at ~ 600 mhz. the next version uses the coppermine core, which goes to 1000 mhz, and the chips that end with e are coppermines. even though your chip doesn't say e, it still is because it is impossible for it to run at 850 mhz and not be a coppermine.
The "E" means you have half the cache running at the full speed of the precessor. The "B" would mean it is a 133Mhz FSB processor. Hope this clears some things up a bit. <IMG SRC="smilies/biggrin.gif" border="0">