| 1 | <HTML> |
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| 2 | <HEAD> |
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| 3 | <META NAME="GENERATOR" CONTENT="Adobe PageMill 3.0 per Windows"> |
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| 4 | <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> |
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| 5 | <TITLE>PTB Modem Time Service </TITLE> |
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| 6 | </HEAD> |
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| 7 | <BODY> |
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| 8 | |
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| 9 | <H3>PTB Modem Time Service and other European Laboratories Time |
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| 10 | Services</H3> |
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| 11 | |
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| 12 | <HR ALIGN=LEFT> |
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| 13 | |
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| 14 | <H4>Synopsis</H4> |
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| 15 | |
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| 16 | <P>Address: 127.127.23.<I>u</I> <BR> |
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| 17 | Reference ID: <TT>PTB</TT> <BR> |
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| 18 | Driver ID: <TT>ACTS_PTB</TT><BR> |
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| 19 | Serial Port: <TT>/dev/ptb<I>u</I></TT>; 1200 baud, 8-bits, no |
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| 20 | parity <BR> |
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| 21 | Requires: <TT>/usr/include/sys/termios.h</TT> header file with |
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| 22 | modem control</P> |
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| 23 | |
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| 24 | <H4>Description</H4> |
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| 25 | |
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| 26 | <P>This driver supports the PTB Automated Computer Time Service |
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| 27 | (ACTS) and it is a modified version of the NIST ACTS driver so |
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| 28 | see it for more informations..</P> |
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| 29 | |
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| 30 | <P>It periodically dials a prespecified telephone number, receives |
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| 31 | the PTB timecode data and calculates the local clock correction. |
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| 32 | It designed primarily for use when neither a radio clock nor connectivity |
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| 33 | to Internet time servers is available. For the best accuracy, |
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| 34 | the individual telephone line/modem delay needs to be calibrated |
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| 35 | using outside sources.</P> |
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| 36 | |
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| 37 | <P>The only change between this driver and the NIST one is the |
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| 38 | data format. Infact PTB data format is the following:</P> |
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| 39 | |
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| 40 | <P><FONT SIZE="-1" FACE="Courier New">Data format<BR> |
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| 41 | 0000000000111111111122222222223333333333444444444455555555556666666666777777777 |
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| 42 | 7<BR> |
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| 43 | 0123456789012345678901234567890123456789012345678901234567890123456789012345678 |
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| 44 | 9<BR> |
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| 45 | 1995-01-23 20:58:51 MEZ 10402303260219950123195849740+40000500 |
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| 46 | *<BR> |
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| 47 | A B C D EF G H IJ K L M N O P Q R S T U V W |
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| 48 | XY Z<CR><LF><BR> |
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| 49 | A year<BR> |
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| 50 | B month<BR> |
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| 51 | C day<BR> |
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| 52 | D hour<BR> |
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| 53 | E : normally<BR> |
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| 54 | A for DST to ST switch first hour<BR> |
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| 55 | B for DST to ST switch second hour if not marked in H<BR> |
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| 56 | F minute<BR> |
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| 57 | G second<BR> |
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| 58 | H timezone<BR> |
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| 59 | I day of week<BR> |
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| 60 | J week of year<BR> |
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| 61 | K day of year<BR> |
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| 62 | L month for next ST/DST changes<BR> |
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| 63 | M day<BR> |
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| 64 | N hour<BR> |
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| 65 | O UTC year<BR> |
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| 66 | P UTC month<BR> |
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| 67 | Q UTC day<BR> |
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| 68 | R UTC hour<BR> |
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| 69 | S UTC minute<BR> |
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| 70 | T modified julian day (MJD)<BR> |
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| 71 | U DUT1<BR> |
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| 72 | V direction and month if leap second<BR> |
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| 73 | W signal delay (assumed/measured)<BR> |
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| 74 | X sequence number for additional text line in Y<BR> |
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| 75 | Y additional text<BR> |
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| 76 | Z on time marker (* - assumed delay / # measured delay)<BR> |
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| 77 | <CR>!<LF> ! is second change !<BR> |
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| 78 | </FONT><BR> |
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| 79 | This format is an ITU-R Recommendation (ITU-R TF583.4) and is now available from the primary |
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| 80 | timing centres of the following countries: |
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| 81 | Austria, Belgium, Germany, Italy, The Netherlands, Poland, Portugal, Romania, Spain, Sweden, |
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| 82 | Switzerland, Turkey, United Kingdom. |
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| 83 | Some examples are: |
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| 84 | </P> |
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| 85 | |
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| 86 | <UL> |
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| 87 | <LI>In Germany by Physikalisch-Technische Bundesanstalt (PTB)'s |
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| 88 | timecode service. Phone number: +49 5 31 51 20 38. |
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| 89 | </UL> |
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| 90 | |
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| 91 | <BLOCKQUOTE> |
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| 92 | <P>For more detail, see <A HREF="http://www.ptb.de/english/org/4/43/433/disse.htm">http://www.ptb.de/english/org/4/43/433/disse.htm</A></P> |
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| 93 | </BLOCKQUOTE> |
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| 94 | |
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| 95 | <UL> |
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| 96 | <LI>In the UK by National Physical Laboratory (NPL)'s TRUETIME |
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| 97 | service. Phone number: 0891 516 333 |
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| 98 | </UL> |
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| 99 | |
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| 100 | <BLOCKQUOTE> |
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| 101 | <P>For more detail, see <A HREF="http://www.npl.co.uk/npl/ctm/truetime.html">http://www.npl.co.uk/npl/ctm/truetime.html</A></P> |
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| 102 | </BLOCKQUOTE> |
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| 103 | |
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| 104 | <UL> |
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| 105 | <LI>In Italy by Istituto Elettrotecnico Nazionale "Galileo |
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| 106 | Ferrais" (IEN)'s CTD service. Phone number: 166 11 46 |
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| 107 | 15 |
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| 108 | </UL> |
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| 109 | |
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| 110 | <BLOCKQUOTE> |
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| 111 | <P>For more detail, see <A HREF="http://www.ien.it/tf/time/Pagina42.html">http://www.ien.it/tf/time/Pagina42.html</A></P> |
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| 112 | </BLOCKQUOTE> |
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| 113 | |
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| 114 | <UL> |
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| 115 | <LI>In Switzerland by Swiss Federal Office of Metrology 's timecode |
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| 116 | service. Phone number: 031 323 32 25 |
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| 117 | </UL> |
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| 118 | |
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| 119 | <BLOCKQUOTE> |
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| 120 | <P>For more detail, see <A HREF="http://www.ofmet.admin.ch/de/labors/4/Zeitvert.html%20">http://www.ofmet.admin.ch/de/labors/4/Zeitvert.html |
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| 121 | </A></P> |
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| 122 | </BLOCKQUOTE> |
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| 123 | |
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| 124 | <UL> |
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| 125 | <LI>In Sweden by SP Swedish National Testing and Research Institute |
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| 126 | 's timecode service. Phone number: +46 33 415783 |
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| 127 | </UL> |
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| 128 | |
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| 129 | <BLOCKQUOTE> |
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| 130 | <P>For more detail, see <A HREF="http://www.sp.se/pne/ElectricalMetrology/ElMeteng/frameset.htm">http://www.sp.se/pne/ElectricalMetrology/ElMeteng/frameset.htm</A><BR> |
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| 131 | <BR> |
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| 132 | </P> |
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| 133 | </BLOCKQUOTE> |
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| 134 | |
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| 135 | <H4>Fudge Factors</H4> |
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| 136 | |
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| 137 | <DL> |
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| 138 | <DT><TT>time1 <I>time</I></TT> |
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| 139 | <DD>Specifies the time offset calibration factor, in seconds |
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| 140 | and fraction, with default 0.0. |
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| 141 | <DT><TT>time2 <I>time</I></TT> |
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| 142 | <DD>Not used by this driver. |
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| 143 | <DT><TT>stratum <I>number</I></TT> |
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| 144 | <DD>Specifies the driver stratum, in decimal from 0 to 15, with |
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| 145 | default 0. |
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| 146 | <DT><TT>refid <I>string</I></TT> |
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| 147 | <DD>Specifies the driver reference identifier, an ASCII string |
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| 148 | from one to four characters, with default PTB. |
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| 149 | <DT><TT>flag1 0 | 1</TT> |
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| 150 | <DD>Not used by this driver. |
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| 151 | <DT><TT>flag2 0 | 1</TT> |
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| 152 | <DD>Not used by this driver. |
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| 153 | <DT><TT>flag3 0 | 1</TT> |
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| 154 | <DD>Not used by this driver. |
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| 155 | <DT><TT>flag4 0 | 1</TT> |
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| 156 | <DD>Not used by this driver. |
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| 157 | </DL> |
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| 158 | |
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| 159 | <P>Additional Information</P> |
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| 160 | |
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| 161 | <P>A keyword in the ntp.conf file permits a direct connection |
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| 162 | to a serial port of source of time like IEN CTD signal. It is |
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| 163 | sufficient to use the string DIRECT in place of the phone number.</P> |
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| 164 | |
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| 165 | <P>Example:</P> |
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| 166 | |
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| 167 | <P><FONT FACE="Courier New">server 127.127.23.1</FONT></P> |
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| 168 | |
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| 169 | <P><FONT FACE="Courier New">phone DIRECT</FONT></P> |
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| 170 | |
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| 171 | <P><A HREF="refclock.htm">Reference Clock Drivers</A> <HR ALIGN=LEFT></P> |
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| 172 | |
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| 173 | <ADDRESS>by Marco Mascarello (masca@tf.ien.it) for David L. Mills |
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| 174 | (mills@udel.edu)</ADDRESS> |
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| 175 | |
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| 176 | </BODY> |
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| 177 | </HTML> |
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| 178 | |
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