FSBP3:     OPCODE: db,e9     IIT ONLY   UNDOCUMENTED

            Selects the scratchpad bank3 used by the FMUL4X4 internally.
       Not very useful but funny to look at... How-to: load
       any value into bank 0,1 or 2 until you have a full 8
       registers, then execute this bankswitch. Using a
       debugger like CodeView you are now able to inspect the
       bank3 registers. (most likely to take 6 clocks)



TRIGONIOMETRIC FUNCTIONS:

       Apparently the IIT 2c87 recognises and executes some
       i80387 trigoniometric functions. UNDOCUMENTED
       FSIN (sine) and FCOS (cosine) have been tested and function
       according to the Intel 80387 specifications. FSINCOS
       (available on the Intel 80287XL, 80387 and up) does not
       work.