INT 1A - TIME - GET REAL-TIME CLOCK DATE (AT,XT286,PS)
AH = 04h
CF clear to avoid bug (see below)
Return: CF clear if successful
CH = century (BCD)
CL = year (BCD)
DH = month (BCD)
DL = day (BCD)
CF set on error
Notes: DR-DOS 7.02 (after 1998-06-06) and 7.03 hook this function and correct
the century to 20xx if the reported year is 1900..1980 to auto-fix
ROM-BIOSes which are not Year 2000 compliant. On a running system,
it would also correct the rollover bug from 1999/12/31 to 2000/01/01.
The latter can be turned off using the new CONFIG.SYS YEAR2000=ON|OFF
command, as hooking INT 1Ah can sometimes cause compatibility
problems with 3rd party software, e.g. NCR/Symbios/LSI Logic-based
SDMS PCI SCSI drivers (including all OEM drivers like from Asus,
Noma, etc.), some Flash-BIOS software like Asus PFLASH, Quarterdeck's
QEMM Stealth and Quick-Boot features.
Using EXCLUDESTEALTHINT=1A, though, will allow QEMM's Stealth features
to coexist with the DR-DOS Year 2000 rollover support.
Actually, the Y2K-fix is provided since OpenDOS 7.02 BETA 2+
(1997-08-13), but although these older releases corrected the
ROM-BIOS, they didn't pass all Y2K-test suites and had some obscure
and inexplicable PCI problems due to the fact that the original
INT 1Ah was called via indirect means. Newer releases, however, use
a dynamically fixed-up direct jump to avoid these problems.
PC DOS 7 plus Y2K fixes and PC DOS 2000 provide similar, though not
identical means, which cannot be switched off.
MS-DOS and older issues of PC DOS do not provide any such means, and
thus requires extra Y2K-TSRs to be loaded when run on buggy BIOSes.
BUG: some BIOSes, such as the 1998/07/25 system ROM in the Compaq Deskpro
EP/SB, leave CF unchanged if successful, so CF should be cleared
before calling this function
SeeAlso: AH=02h,AH=04h"Sperry",AH=05h,INT 21/AH=2Ah,INT 4B/AH=02h"TI"