80X87 and Interactive Unix

[Heimir Thor Sverrisson]

Does anyone out there know how Interactive Unix determines the
presence of a numeric co-processor.  I've been bitten by the
divide by zero bug in awk on a 33 MHz clone.  The Bios setup
says that there is no co-processor installed, and I can find no
jumpers on the motherboard to change.

I did get some 'floating point fixes' but they just fiddle with
location 0x14 in the CMOS-RAM.  If it's contents are 0x41 Unix
says that I'm having an 80287 and if I change it to 0x43 it
says that I've got a 80387!

What tells Unix that I'm having a co-processor in the first place?
Another clone machine I'm running has 0x41 in /dev/cram but it
reports software emulation for floating point!  What am I missing
here?
--
Heimir Thor Sverrisson			heimir at hafro.is