Subject: Re: Date is stuck
From: phys169@csc.canterbury.ac.nz
Organization: University of Canterbury, Christchurch, New Zealand
Nntp-Posting-Host: cantva.canterbury.ac.nz
Lines: 25

In article <1993Apr14.132300.27816@kosman.uucp>, kevin@kosman.uucp (Kevin O'Gorman) writes:
> Anybody seen the date get stuck?
> 
> I'm running MS-DOS 5.0 with a menu system alive all the time.  The machine
> is left running all the time.
> 
> Suddenly, the date no longer rolls over.  The time is (reasonably) accurate
> allways, but we have to change the date by hand every morning.  This involves
> exiting the menu system to get to DOS.
> 
> Anyone have the slightest idea why this should be?  Even a clue as to whether
> the hardware (battery? CMOS?) or DOS is broken?

I bet it suddenly started sticking when you  started leaving the PC running the
menu all night.  There is a limitation/bug in the date roll-over software in
PC's that means you have to be doing something like waiting for keyboard input
via a DOS call rather than a BIOS call (as menus often use) otherwise the code
to update the date after midnight never gets called. 

Somebody might be able to correct the details in case I've mis-rememberred
them, but I think you have to change the menu program (if you have the sources)
or add a TSR or system patch or something.  As far as I know the CMOS clock
keeps the right time (in fact about 7 seconds/day better than DOS's clock).

Mark Aitchison, University of Canterbury.
