INT 15 - SYSTEM - POWER-ON SELF-TEST ERROR LOG (PS50+IBM PS/2 Models 50,60,70,80)
	AH = 21h
	AL = subfunction
	    00h read POSTsee Power-On Self-Test log
	    01h write POSTsee Power-On Self-Test log
		BH = device ID
		BL = error code
Return: CF clear if successful
	CF set on error
	AH = status
	    00h OK
	    01h list full
	    02h unsupported subfunction
	    80h invalid command
	    86h unsupported function
	if function 00h:
	   BX = number of error codes stored
	   ES:DI -> error log
Notes:	the log is a series of words, the first byte of which identifies the
	  error code and the second the device.
	supported by AMIAmerican Megatrends, Inc.(American Megatrends, Inc.) A hardware, software and firmware company founded in 1985. PCI 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.
	IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. considers this a required 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. function
	if the device ID is FFh, the "error code" is the actual device number
	  minus 255 (thus these devices have no specific error codes)
SeeAlso: AH=23h"SYSTEM",AH=24h"SYSTEM"