INT 15 - BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. - SET EVENT WAIT INTERVAL (ATIBM PC AT,PS50+IBM PS/2 Models 50,60,70,80)
	AH = 83h
	AL = subfunction
	    00h set interval
		CX:DX = microseconds to delay
		ES:BX -> byte whose high bit is to be set at end of interval
	    01h cancel wait interval
Return: CF set on error or function already busy
	    AH = status
		80h invalid command (PCIBM PC,PCjr)
		86h function not supported (XTIBM PC XT and later)
	CF clear if successful
Notes:	the resolution of the wait period is 977 microseconds on many systems
	  because many BIOSes use the 1/1024 second fast interrupt from the ATIBM PC AT
	  real-time clock chip which is available on INT 70
	IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. ATIBM PC AT 1984/1/10 BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. ignores AL and always performs subfunction 00h
SeeAlso: AH=41h,AH=86h,INT 70,MEM 0040h:0098h,MEM 0040h:009Ch