Those would be simply unused and ignored - but the only way to be sure is to test. FPU that does accept async clock would freeze with the extra clock generator missing, or have different performance (provided the clock not the same frequency as CPU clock).

elianda wrote on 2016-11-30, 12:48:

Referring to this: ftp://retronn.de/docs/FPU/coproc.txt

Thanks ! I always wanted to know the difference between the 287 and 387 math co variants..