Int 2F Fn 4502  U - Microsoft Profiler (prof.com/vprod.386) - Set Samplin  [G]

   AX = 4502h
   BL = sampling rate for PROF.COM (0 < BL <= 13)
       (01h = 8192/s, 04h = 1024/s, 08h = 32/s, 0Dh = 1/s)
   CX = sampling rate for VPROD.386

Note:  for PROF.COM, this programs the CMOS clock by setting BL+2 as the
     low four bits of CMOS register 0Ah.  The interruption rate is
     1 SHL (15 - BL) per second.

See Also: AX=4501h,AX=4503h