HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

            INT 1A,4 - Read Real Time Clock Date  (XT 286,AT,PS/2)

       AH = 04

       on return:
       CH = century in BCD (decimal 19 or 20)
       CL = year in BCD
       DH = month in BCD
       DL = day in BCD
       CF = 0 if successful
          = 1 if error or clock not operating

       - calling this interrupt will update the DOS maintained date and
         reset the BIOS Data Area date rollover flag at 40:70
       - see   RTC

Esc or Alt-X to exit int 1a,4 Home/PgUp/PgDn/End ←↑↓→
Converted to HTML in 2006 by Timo Bingmann