INT 15,C0 - Return System Configuration Parameters (PS/2 only)

	AH = C0
	on return:
	CF = 0 if successful
	   = 1 if error
	AH = when CF set, 80h for PC & PCjr, 86h for XT
	     (BIOS after 11/8/82) and AT (BIOS after 1/10/84)
	ES:BX = pointer to system descriptor table in ROM of the format:
	Offset Size	     Description
	  00   word   length of descriptor (8 minimum)
	  02   byte   model byte (same as F000:FFFE, not reliable)
	  03   byte   secondary model byte
	  04   byte   BIOS revision level (zero based)
	  05   byte   feature information, see below
	  06   dword  reserved
	Feature Information
	|7|6|5|4|3|2|1|0|  Feature Byte
	 | | | | | | | `---- reserved
	 | | | | | | `----- 0=PC bus, 1=Micro Channel
	 | | | | | `------ Extended BIOS Data Area (EBDA)allocated
	 | | | | `------- wait for external event supported
	 | | | `-------- INT 15,4F used (kbd intercept)
	 | | `--------- RTC present
	 | `---------- 2nd 8259 present
	 `----------- DMA channel 3 used by fixed disk BIOS
	- see	MACHINE ID