Date: Mon, 21 Feb 2000 08:11:18 +0600 (LKT) From: Kalum Somaratna aka Grendel <kalum AT crosswinds DOT net> X-Sender: root AT darkstar DOT grendel DOT net To: djgpp AT delorie DOT com Subject: RE: Accurate timing! In-Reply-To: <Pine.LNX.4.10.10002190656170.903-100000@midpec.com> Message-ID: <Pine.LNX.4.10.10002210805370.1141-100000@darkstar.grendel.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: djgpp AT delorie DOT com Errors-To: dj-admin AT delorie DOT com X-Mailing-List: djgpp AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk On Sat, 19 Feb 2000, Prashant TR wrote: > On Fri, 18 Feb 2000, Manni Heumann wrote: > > > It won't work under windows, you should not try to access a floppy drive with > > the timer ticking faster, and your system time will be wrong afterwards. > > Shouldn't try using any disk drive with a modified timer. > > If you set the timer faster in a program your system time will indeed run faster during the apps execution but at the end of the apps execution you can read the CMOS time (which is unafected) and reset the system time to it, which should avoid any wrong system times. BTW this whole issue can be avoided by making sure that the original timer interrupt handler is called at the default BIOS rate. All you do is program the timer chip to a higher rate but make sure that the new (ie your) interrupt handler calls the old handler at exactly the same rate that the BIOS would have done. This will avoid all the floppy drive related problems also. Any minor system date variations due to the fact that the old interrupt handler not being called at _exactly_ the BIOs deafault rate can be avoided by using the CMOS to set the system date upon termination of the spplication. Grendel. Hi, I'm a signature virus. plz set me as your signature and help me spread :)