On Monday 04 November 2002 09:02 pm, John Summerfield wrote: > > Then came our modern age, the age of flat memory models. Segment > > registers are anachronistic. Toss them out. One simple, flat memory model > > is the only way to go. > > The segment registers still exist. Their use was expanded and they got > renamed. >
Their size was expanded, but they are not typically used to truly "segment" memory any more, as most systems use the unified, flat memory model. Also, the segments no longer point directly to physical addresses but rather to virtual addresses. The 80286 made things more complex than the 8086/80186, but the 80386 got *really* interesting. I haven't gotten my hands on the Itanium (what a dorky name!) architecture manual yet, but I'm curious to see what Intel came up with when they started with a clean slate. I have heard that the pipelining is extremely sophisticated and is capable by design of extraordinary efficiency, but also that it is very difficult to create a compiler that will generate instructions in optimal order for this complex multi-stage, multi-state, multi-path pipeline. Scott -- ----------------------------------------------------------------------------- Scott D. Courtney, Senior Engineer Sine Nomine Associates [EMAIL PROTECTED] http://www.sinenomine.net/
