The first detailed description I ever heard of the Pentium processor was that it was a 32 bit processor with 16 8, 4, 2 and doubtless even 1 bit ancestors and that it was reverse compatible with all of them, making it an ugly processor compared with say the clean and extremely fast alpha, sadly bought out and killed off by bigger rivals, but one that sells well.

I understand that the AMD can cope with 16 bit instructions. Is it reverse compatible all the way? My pop has some very old programs including his very own text editor and related programs and he doesn't want to change. Would an AMD 64 as a birthday present be incompatible ?

I know the Windows 64 bit OS can't cope with 16 bit instuctions (pah!) but I was thinking that he could maybe run DOS and old programs inside a VMWare virtual machine. The main operating system would be linux 64 as it seems to be way ahead of windows, and with VMWare I can always run windows as a baby OS if he wants it.

Whatcha think?