I still have not understood at which level some FPU instructions are
emulated on 68060.
- Inside the 68060 itself ?
- Inside the TOS 4.04, through Line-F exception ?
- Inside the CT60 OS, through Line-F exception ?
CT60 OS = FireTOS = TOS 4.04. Normally, TOS 4.04 does NOT run on 68060 and even does not use any FPU instructions, I wouldn't be surprised if it isn't compiled for 68030 at all.
Then, if you do upgrade to 68060 you must deal with missing instructions somehow (else they generate exception => bombs => good bye). Motorola provides so called FPSP - Floating Point Support Package where all missing 68020/68881 instructions are emulated, you just hook it on OS vector and here you go.
That's a bit mysterious...
Not really! :)