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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node108.html b/sag-0.6.1-www/Invisible/sag-0.6/node108.html new file mode 100644 index 0000000..262a902 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node108.html @@ -0,0 +1,56 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>The hardware and software clocks</TITLE> +<META NAME="description" CONTENT="The hardware and software clocks"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1675" HREF="node109.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1673" HREF="node106.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1667" HREF="node107.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1677" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1678" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1676" HREF="node109.html">Showing and setting time</A> +<B>Up:</B> <A NAME="tex2html1674" HREF="node106.html">Keeping Time</A> +<B> Previous:</B> <A NAME="tex2html1668" HREF="node107.html">Time zones</A> +<BR> <P> +<H1><A NAME="SECTION001220000000000000000">The hardware and software clocks</A></H1> +<P> + A personal computer has a battery driven hardware clock. The + battery ensures that the clock will work even if the rest of + the computer is without electricity. The hardware clock can + be set from the BIOS setup screen or from whatever operating + system is running. +<P> + The Linux kernel keeps track of time independently from the + hardware clock. During the + boot, Linux sets its own clock to the same time as the hardware + clock. After this, both clocks run independently. Linux + maintains its own clock because looking at the hardware is + slow and complicated. +<P> + The kernel clock always shows universal time. This way, the + kernel does not need to know about time zones at all--the simplicity + results in higher reliability and makes it easier to update the + time zone information. Each process handles time zone conversions + itself (using standard tools that are part of the time zone + package). +<P> + The hardware clock can be in local time or in universal time. + It is usually better to have it in universal time, because + then you don't need to change the hardware clock when daylight + savings time begins or ends (UTC does not have DST). Unfortunately, + some PC operating systems--including MS-DOS, Windows, OS/2--assume + the hardware clock shows local time. Linux can handle either, but + if the hardware clock shows local time, then it must be modified + when daylight savings time begins or ends (otherwise it wouldn't + show local time). +<P> +<BR> <HR> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |