>>>>Are you saying that apps that I've written on my XP with AMD processor will not work on an Intel Win10 pc?
>>>>Rich
>>>
>>>No, that's not what I say. AMD CPU's are Intel-compatible, what Microsoft calls "Intel type", so you don't have to worry.
>>
>>The x86-64 instruction set (commonly called AMD64 by many entities other than Intel) was created by AMD, not Intel.
>>
>>So, Intel CPUs are AMD-compatible ;)
>
>not debating your statement, but as vfp is only 32 bit, only the part on the left of the hyphen is important ;-))

When was the last time it was possible to buy a Windows computer that was not x86-64 capable? ;)

>Although I am pretty certain that vfp6 and higher cannot be made to run on an Intel 8086, guessing at least 80386 instruction set is neccessary, which would imply 80386SX as lower bound ;-)

The 386SX could theoretically address up to 16MB RAM so might meet lower bound for W95 or W98. However, it was a budget chip and ISTR a lot of 386SX mobos were limited to 2MB RAM. W95 minimum RAM (per MS) was 4MB: https://support.microsoft.com/en-us/kb/138349 . That was back in the days when MS "minimum" figures were so low that you had to double them to get a system that was usably fast and didn't crash once per hour when running more than 1 program at a time.