Thanks again for all these new reports! 😀
It showed me that a lot of the new logic I put in this updated CHKCPU works as expected. Only the FPU detection on 386 systems is clearly bugged.
When Intel introduced the 80387 FPU in 1986, the 80386 CPU was already a year on the market. During that time, there were motherboards that allowed to install an 80287 FPU next to the 80386, while also providing a 80387 socket for a future upgrade FPU. So in those days a 386 could be paired with a 287 or 387 FPU. I never saw a board like that however, did any of you?
Anyway, as I read about a way to tell the 287/387 apart, I put this logic in CHKCPU.
Thanks to your testing I know now that this logic doesn’t work!
In hindsight, it is unlikely that we ever encounter such a rare 386+287 system after all these years. Most of them will have vanished or have been upgraded with a 387 FPU.
Therefore I decided to delete the 287/387 detection on 386 systems and consider the 386+287 indication obsolete. The next CHKCPU version will then always show a 387 when an FPU is detected on a 386 system...
As I haven’t found out yet how to identify other FPUs, like IIT 3C87, 4C87 and Cyrix 83D87, those will also be shown as 387 for the time being. 😉
I will report back when the next CHKCPU beta is ready.
Jan