INT 2F - Microsoft Profiler (PROF.COM/VPROD.386) - START PROFILING

	AX = 4503h
Notes:	Profiling is also turned on by the key combinations
	  LeftShift + RightShift + Alt and LeftShift + RightShift + Ctrl
	for PROF.COM, this call programs the CMOS clock by reading register
	  0Ch, and setting bit 6 of register 0Bh.  It then makes sure that IRQ8
	  is unmasked
SeeAlso: AX=4504h