HP Forum Archive 19

[ Return to Index | Top of Index ]

Navigation Module Message #1 Posted by Jeff Kearns on 17 Oct 2010, 6:06 p.m. HP 41C with Nav - Time and X Modules Why was I the only bidder on this auction? Not only does the unit come with the Nav, x-functions, and time modules but it has the QUAD memory module too, with all manuals! I have always wanted a navigation module and thought this was a good buy considering that one sold recently for $125. Considering the high prices for recent sales of the 15C (I got one in excellent shape at a garage sale last year for $5), am I missing something? Jeff

Re: Navigation Module Message #2 Posted by Raymond Del Tondo on 17 Oct 2010, 6:40 p.m., in response to message #1 by Jeff Kearns Congrats, very nice item for a low price:-) Why you were the only bidder: Maybe because the seller did not look at his watch when starting the auction. At 13:30 many people may just have gotten tired from eating;-) HTH

Re: Navigation Module Message #3 Posted by Jeff Kearns on 17 Oct 2010, 6:45 p.m., in response to message #2 by Raymond Del Tondo Thanks! I thought so. One constraint may have been the US only shipping policy of this seller that would certainly limit the bidder pool significantly. I live in Canada but used a friend's address in the US for shipping. I look forward to having a spare 41C too! Regards, Jeff Kearns

Re: Navigation Module (w/enhanced HP-41C) Message #4 Posted by Karl Schneider on 17 Oct 2010, 10:06 p.m., in response to message #1 by Jeff Kearns Jeff -- Congratulations on purchasing a great bargain for a collector! Looks to be a non-tallkeys HP-41C, like mine from 1980. A few years ago, I probably would have competed in the auction, but I have all the main pieces of the full ensemble shown. Your new HP-41C with Quad Memory, Time Module, and Navigation Pac is able to run Tom Sherman's 1985 celestial locator application program for navigation, which I have loaded on my HP-41's. Given the local lat/lon and the UTC time and date, it will identify the position in the sky of the sun, moon, Venus, Mars, Jupiter, Saturn, and a broad selection of stars useful for navigation -- in short, all the celestial objects supported by the Nav Pac. Each calculation takes several minutes, but it's never wrong... The X-Functions module provides some backup storage and other useful functions, but you might want X-memory modules as well. -- KS Edited: 17 Oct 2010, 11:12 p.m. after one or more responses were posted

Re: Navigation Module (w/enhanced HP-41C) Message #5 Posted by Jeff Kearns on 17 Oct 2010, 10:37 p.m., in response to message #4 by Karl Schneider Karl, Thanks for your post! I actually work for a company that makes ECDIS (Electronic Chart Display and Information Systems) products for warships and submarines, although my background in the navy was primarily in marine engineering. I have always had an interest in navigation and astronomy and have played around with the Nav Pac on my Palm-based P41CX. It should be an interesting exercise to run Tom Sherman's 1985 celestial locator application program for navigation - when I find it!!! So far, I found reference to it in an old post here, in which you participated: Tom Sherman's Celestial Locator Post If I cannot find it on my own, I will be in touch. Regards, Jeff

Tom Sherman's celestial locator for HP-41 Message #6 Posted by Karl Schneider on 18 Oct 2010, 2:42 a.m., in response to message #5 by Jeff Kearns Jeff -- Geir Isene modified the program to provide a quicker, more compact user interface. I then inserted a single valuable instruction. I possess the full hardcopy documentation from Tom with source listing, but I use Geir's version. Geir's version includes the following instruction sequence in two places: FS? 31 XEQ "DMD" Flag 31 is a system flag that indicates the date format, but I don't seem to have the program "DMD". I suspect that it is Geir's own program for processing the date or its format. Geir's program fits on three HP-41 magnetic cards (Tom's original fits on two). -- KS

Re: Tom Sherman's celestial locator for HP-41 Message #7 Posted by Geir Isene on 18 Oct 2010, 7:45 a.m., in response to message #6 by Karl Schneider Right, the DMD... What it does is just to convert the date formats - between DD.MMYYYY and MM.DDYYYY (either way), like this: LBL "DMD" ENTER INT X<>Y FRC 100 * ENTER INT X<>Y 100 / + X<>Y 100 / + END Edited: 18 Oct 2010, 7:46 a.m.

Re: Tom Sherman's celestial locator for HP-41 Message #8 Posted by Thomas Klemm on 18 Oct 2010, 10:19 a.m., in response to message #7 by Geir Isene 01 LBL "DMD" 02 INT 03 LASTX 04 FRC 05 100 06 * 07 INT 08 X<>Y 09 LASTX 10 FRC 11 + 12 100 13 / 14 + 15 END Saves a few bytes. Best regards Thomas

Re: Tom Sherman's celestial locator for HP-41 Message #9 Posted by Geir Isene on 18 Oct 2010, 12:33 p.m., in response to message #8 by Thomas Klemm Excellent.

Re: Tom Sherman's celestial locator for HP-41 Message #10 Posted by Geir Isene on 19 Oct 2010, 6:25 a.m., in response to message #9 by Geir Isene LASTX is perhaps the least used instruction in my programs. I should get used to it.

Geir Isene's improved version of celestial locator program Message #11 Posted by Karl Schneider on 21 Oct 2010, 3:41 a.m., in response to message #5 by Jeff Kearns Jeff -- You had found one of the threads regarding Tom Sherman's HP-41 celestial locator program, but there was another thread in 2006 in which Tom contributed and Geir posted his improved version of the program: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv016.cgi?read=91858#91858 I will copy and paste Geir's version below, together with the "DMD" program he omitted in 2006 (as recently refined by Thomas Klemm), and also including one worthwhile instruction added by me (003 DEG, to ensure that the degree angular mode is set for calculations). The "DMD" program allows the user to maintain European-style date mode (dd.mmyyyy), which is initiated by running the Time Module command "DMY" (which sets Flag 31). The Nav Pac subroutine "FA" requires that the input date be formatted US-style (mm.ddyyyy), as documented on page 41 of the Nav Pac manual. As a side note, years outside the range 1900-1999 are displayed on the HP-41 using four digits. The full dates look nicer in European format on the HP-41's 12-character display. For guidance in usage, please see Geir's description of the features of his program, in the thread of 2006. I'll also note that entry of an arbitrary date and time is of the form <date> ENTER <time>, occupying two stack levels. In the source code listing, "|-" is the unprintable 'append' character shift-K in ALPHA mode. The complete, improved program: 001 *LBL "SKY" 051 "LO" 101 GTO 02 151 DATE 002 LBL e 052 XROM "DSPLO" 102 LBL a 152 FS? 31 003 DEG 053 "|-?" 103 "VENUS" 153 XEQ "DMD" 004 CF 01 054 PROMPT 104 AVIEW 154 STO 30 005 CF 02 055 XROM "*HR" 105 6 155 TIME 006 SF 00 056 STO 08 106 LBL 06 156 LBL 12 007 CLK24 057 LBL E 107 XEQ 01 157 RCL 54 008 "DT+TM=<NOW>" 058 "S,V O,M *,J ,SA" 108 .017 158 HMS- 009 CF 22 059 PROMPT 109 + 159 FS? 03 010 PROMPT 060 LBL A 110 STO 34 160 1 011 FC? 22 061 "SUN" 111 XROM "*VENUS" 161 FS? 03 012 GTO 10 062 AVIEW 112 GTO 02 162 HMS+ 013 STO 55 063 3 113 LBL b 163 HR 014 X<>Y 064 LBL 03 114 "MARS" 164 RTN 015 FS? 31 065 XEQ 01 115 AVIEW 165 LBL 02 016 XEQ "DMD" 066 .012 116 7 166 RCL 44 017 STO 30 067 + 117 LBL 07 167 RCL 45 018 SF 02 068 STO 34 118 XEQ 01 168 + 019 LBL 10 069 XROM "*SUN" 119 .019 169 RCL 08 020 RCL 54 070 GTO 02 120 + 170 - 021 "TZ= " 071 LBL B 121 STO 34 171 RCL 07 022 ARCL X 072 "MOON" 122 XROM "*MARS" 172 RCL 46 023 PROMPT 073 AVIEW 123 GTO 02 173 XROM "*SRT" 024 STO 54 074 4 124 LBL c 174 CF 21 025 "N" 075 LBL 04 125 "JUPITER" 175 BEEP 026 ASTO Y 076 XEQ 01 126 AVIEW 176 FIX 1 027 "SUM.TIME? <" 077 .026 127 8 177 "ALT= " 028 FS? 03 078 + 128 LBL 08 178 ARCL X 029 "|-Y" 079 STO 34 129 XEQ 01 179 AVIEW 030 FC? 03 080 XROM "*MOON" 130 .02 180 PSE 031 "|-N" 081 GTO 02 131 + 181 PSE 032 "|->" 082 LBL C 132 STO 34 182 "AZI= " 033 CF 23 083 "STAR NO= ?" 133 XROM "*JUPIT" 183 ARCL Y 034 AON 084 PROMPT 134 GTO 02 184 AVIEW 035 PROMPT 085 INT 135 LBL d 185 FC? 01 036 AOFF 086 STO 47 136 "SATURN" 186 STOP 037 FC? 23 087 FIX 0 137 AVIEW 187 SF 01 038 GTO 11 088 "STAR " 138 9 188 GTO IND 56 039 ASTO X 089 ARCL 47 139 LBL 09 189 *LBL "DMD" 040 X NE Y? 090 AVIEW 140 XEQ 01 190 INT 041 SF 03 091 5 141 .024 191 LASTX 042 LBL 11 092 LBL 05 142 + 192 FRC 043 RCL 07 093 XEQ 01 143 STO 34 193 100 044 "LAT" 094 .011 144 XROM "*SATUR" 194 * 045 XROM "DSPL" 095 + 145 GTO 02 195 INT 046 "|-?" 096 STO 34 146 LBL 01 196 X<>Y 047 PROMPT 097 RCL 30 147 STO 56 197 LASTX 048 XROM "*HR" 098 XROM "FA" 148 RCL 55 198 FRC 049 STO 07 099 STO 44 149 FS? 02 199 + 050 RCL 08 100 XROM "*STAR" 150 GTO 12 200 100 201 / 202 + 203 END -- KS Edited: 3 Nov 2010, 12:22 a.m. after one or more responses were posted

Re: Geir Isene's improved version of celestial locator program Message #12 Posted by Jeff Kearns on 23 Oct 2010, 7:28 p.m., in response to message #11 by Karl Schneider Karl, Thanks. I expect to receive the Nav module in the next couple of days - it arrived at my surrogate US destination intact on Thursday. I look forward to trying out these programs and am pleased that, with the DMD program, I can maintain European/Canadian date formats. Best regards, Jeff Kearns

Re: Geir Isene's improved version of celestial locator program Message #13 Posted by Ángel Martin on 25 Oct 2010, 10:17 a.m., in response to message #11 by Karl Schneider I have compiled a ROM file with this program and the ASTRO module U/I add-on, also written by Geir. A MOD file will be posted at TOS in a few days, but it'd good to have some testers before that. Do I hear any volunteers? Cheers, ÁM

Re: Geir Isene's improved version of celestial locator program Message #14 Posted by Jeff Kearns on 3 Nov 2010, 4:53 p.m., in response to message #11 by Karl Schneider Karl, Thanks again for the complete improved program! I have been playing around with the Navigation, Time, and X-Functions modules in what is now a spare 41C. I also picked up a used copy of volumes 1 and 2 of the Admiralty Manual of Navigation - an excellent resource for the theory and practical application of celestial navigation and dead reckoning techniques. As an aside, I remember reading once in a novel (of all places) that the term "dead reckoning" is a morphed or bastardized version of the original abbreviation of deduced reckoning; "ded. reckoning". I will try out the program soon and report back! Jeff

Re: Geir Isene's improved version of celestial locator program Message #15 Posted by Karl Schneider on 4 Nov 2010, 10:42 p.m., in response to message #14 by Jeff Kearns Jeff -- Enjoy using the program, which always gives correct results as far as my unmeasured 'eyeball estimation' tells me. I expect that you've already entered it manually -- I do not have the means of electronic transmission by HP-41, other than the 'electro-physical' method of using magnetic cards. (So that's where "dead reckoning" came from!) -- KS Edited: 6 Nov 2010, 3:51 p.m.

[ Return to Index | Top of Index ]

Go back to the main exhibit hall