INT 1A,2 - Read Time From Real Time Clock (XT 286,AT,PS/2)
AH = 02 on return: CF = 0 if successful = 1 if error, RTC not operating CH = hours in BCD CL = minutes in BCD DH = seconds in BCD DL = 1 if daylight savings time option - on AT with BIOS before 6/10/85, DL is not returned