INT 15 - OS HOOK - DEVICE POSTsee Power-On Self-Test (ATIBM PC AT,PSIBM PS/2, any model)
	AH = 91h
	AL = device type (see #00507)
	ES:BX -> request block for type codes 80h through BFh
	CF clear
Return: AH = 00h
Note:	this function should be hooked by a multitasker to allow other tasks
	  to execute while the 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. is waiting for I/O completion; the default
	  handler merely returns with AH=00h and CF clear
SeeAlso: AH=90h