INT 15,C1 - Return Extended BIOS Data Area Segment (PS/2 only)

	AH = C1

	on return:
	CF = 0 if successful
	   = 1 if error
	AH = when CF set, 80h for PC & PCjr, 86h for XT (BIOS 11/8/82)
	ES = EBDA segment address if PS/2

	- the EBDA is used internally by the PS/2 BIOS routines
	- the EBDA is allocated at the top of user memory by the POST