rcollins@altos86.Altos.COM (Robert Collins) (09/19/90)
In article <4383@bwdls58.UUCP> mlord@bwdls58.bnr.ca (Mark Lord) writes: > >Software compatibility is guaranteed by the simple fact that no existing >software is even ABLE to tell the difference! Because there is none. >(it is theoretically possible to write code to distinguish, but nobody has >published it, and I'm not telling either!). Sure it's possible to tell the difference between the two...if you make the code hardware dependent. As far as I know, it is impossible to tell the difference in a generic way. If you try and preload the prefetch queue and use self modifying code, then that method will work on certain machines, but will fail on others...due to memory and bus wait states, and any memory cache. Sure, I have a method that works on a 16Mhz SX & 16Mhz DX. But that same algorithm fails on my 33Mhz DX with cache! So, if you have a generic method, and it works on ALL DX's and SX's regardless of speed, memory, cache, and bus width (remember, many early 386 machines simply used '286 motherboards with the 386 figured in the schematic -- hence a 16-bit data path), then POST IT! -- "Worship the Lord your God, and serve him only." Mat. 4:10 Robert Collins UUCP: ...!sun!altos86!rcollins HOME: (408) 225-8002 WORK: (408) 432-6200 x4356