The Museum of HP Calculators

HP Forum Archive 19

 HP41/42 Unit ConversionMessage #1 Posted by Egan Ford on 28 Mar 2009, 11:19 a.m. The recent thread on 50g Unit Conversions reminded me just how awesome the 48 and 50 unit support is. So, what do you all use for the 41 and 42? Any good programs/modules for unit conversion? Thanks.

 Re: HP41/42 Unit ConversionMessage #2 Posted by PeterP on 28 Mar 2009, 11:57 a.m.,in response to message #1 by Egan Ford I'm not sure but one of the ROM's has a built in unit conversion. It might be the petroleum pack, but I'm not 100% sure.

 Re: HP41/42 Unit ConversionMessage #3 Posted by Mike (Stgt) on 30 Mar 2009, 4:48 a.m.,in response to message #2 by PeterP It is in the Petroleum Pack (ROM), and in the Thermal Transport ROM too. The unit conversions slightly differ - no-no, not in the conversion factors, sure - but in the number of units for conversion. Ciao.....Mike

 Re: HP41/42 Unit ConversionMessage #4 Posted by Allen on 28 Mar 2009, 12:07 p.m.,in response to message #1 by Egan Ford (Albeit limited) unit conversions on the keyboard -- one of the few things that the 32sii has over the 42s and the 41.

 Re: HP41/42 Unit ConversionMessage #5 Posted by Mike Reed on 30 Mar 2009, 4:07 p.m.,in response to message #4 by Allen I dunno, but it seems to me that the whole issue is a waste of calculator memory. I just memorized (years ago) the conversion constants for the conversions I used frequently, then just "did the math" on my HP when i needed a conversion. When I need another conversion, I just memorize a new constant - I have WAY more memory than the calculator! Fer instance (from memory) 1 US Survey Foot is 0.30480060960 meters, 1 International Foot is 0.304800000 meters, the coefficient of expansion of steel is 0.00000654 units per unit per degree Fahrenheit, the value of PI is 3.14159265358979323846264338327950288419716939937510582097 4944592307816406286208998628034825342117067..., etc. (OK, I fudged a little on that last one >;o) I DO know it to 12 places though!)

 Re: HP41/42 Unit ConversionMessage #6 Posted by Walter B on 28 Mar 2009, 12:21 p.m.,in response to message #1 by Egan Ford The 41C/42S are known "scientific" calculators. In science, almost no unit conversions are needed - some physical constants are more important. I can explain the reasons if you want to ;-)

 Re: HP41/42 Unit ConversionMessage #7 Posted by Andrés C. Rodríguez (Argentina) on 28 Mar 2009, 4:25 p.m.,in response to message #6 by Walter B Walter: 100% agree!

 Re: HP41/42 Unit ConversionMessage #8 Posted by Geoff Quickfall on 28 Mar 2009, 1:12 p.m.,in response to message #1 by Egan Ford User assigned keys, for specific work applications, but no built in conversions to speak of: ```Key 1: quick calculations to convert U.S. gallons (as boarded in the States) of JET A fuel into Kilograms for comparison to onboard guages calibrated in Kilo's. (using standard day temperature as a quick reference) Key 2: quick calculations to convert litres(as boarded in the everywhere else!) of JET A fuel into Kilograms for comparison to onboard guages calibrated in Kilo's(using standard day temperature as a quick reference). Keys 4, 5: Meters to feet and feet to meters, for airspace altitude confirmation with altimeter calibrated in feet. China, Russia and Mongolia to name a few. Keys 7, 8: Inches of mercury to Millibars and vice versa. Used at the flight planning computer which always shows data in inches of mercury, whereas, most European and Asian airports give air pressure in Millibars/hPa. Keys ., 0 the ubiquitous requirement for Celsius to Farenheit and back! ``` Cheers, Geoff

 Re: HP41/42 Unit ConversionMessage #9 Posted by Maximilian Hohmann on 28 Mar 2009, 2:15 p.m.,in response to message #8 by Geoff Quickfall Hi! And what is the "AIRCANADA" key doing? Greetings, Max

 Re: HP41/42 Unit ConversionMessage #10 Posted by Geoff Quickfall on 28 Mar 2009, 2:29 p.m.,in response to message #9 by Maximilian Hohmann Appeasing the politically correct at the company? ;-) Cheers, I know I have asked before but I get 3 day layovers in Mainz. Any chance of a beer, if I give you enough notice?

 Re: HP41/42 Unit ConversionMessage #11 Posted by Maximilian Hohmann on 28 Mar 2009, 2:49 p.m.,in response to message #10 by Geoff Quickfall Hi! Quote:I know I have asked before but I get 3 day layovers in Mainz. Any chance of a beer, if I give you enough notice? Of course! Some years ago, I helped out a (now defunct) company based in Mainz by flying their Cessna 421s every now and then - so I should still be find the way. But in view of the beers, I would rather take the train (it's a 2 1/2 hour trip)... Looking forward to it, Max

 Re: HP41/42 Unit ConversionMessage #12 Posted by Karl Schneider on 28 Mar 2009, 8:32 p.m.,in response to message #8 by Geoff Quickfall Hi, Geoff -- Key 1 and Key 2 may have been helpful in the 1983 "Gimli Glider" incident. -- KS

 Re: HP41/42 Unit ConversionMessage #13 Posted by Geoff Quickfall on 28 Mar 2009, 9:03 p.m.,in response to message #12 by Karl Schneider Your right on that, but unfortunately they did not have the correct measurements from the maintenance drip! The drip sticks were in inches, converted to pounds in the manual, which had to be back converted to metric kilograms for the guages. A dog's breakfast, so to speak. Compoumd that with unserviceable cockpit totalizers and fuel guages, a bad MEL book explanation, new equipment to the company (B767) and you can see the " Swiss Cheese " accident waiting to happen. I think the fuel was metered by the fueler in gallons no less. In a nut shell: ```gallons - inches - pounds - liters - kilograms. ``` Each step completed by a differing department with no onboard confirmation or procedure due to a bad MEL. I always do an independent check of the fuel using the two keys depending on the departure requirements/ I never rely on the onboard system for the complete answer. Cheers, Geoff Edited: 28 Mar 2009, 9:05 p.m.

 Re: HP41/42 Unit ConversionMessage #14 Posted by hpnut on 30 Mar 2009, 3:44 a.m.,in response to message #8 by Geoff Quickfall Hi Geoff, what's that "PHONE" function on the + key in user mode? cheers, hpnut in Malaysia

 Re: HP41/42 Unit ConversionMessage #15 Posted by Geoff Quickfall on 31 Mar 2009, 6:54 p.m.,in response to message #14 by hpnut Hello Hpnut! The phone, code, keys are programs with attached data bases. A primitive PIM in fact which I created before PDA's. Phone key initiates the prompt "Contact?" By inputting at least the first 3 letters of the phone number you want to see you get the completed number as well as the completed name. The name and number reside in the X-memory. Codes are the door codes for access to the ramp at various airports. Place the correct airport identifier in the alpha register after the prompt "AIRPORT?" and you get the code. The WP-A key works the same way. Press the key and you get the prompt "AIRPORT?". Enter any 3 letter airport code; SYD for Sydney, Australia. Get a second "AIRPORT?" prompt and enter the second airport code in; YVR for Vancouver. The result is the Initial True Track and Great Circle distance between the Airports. This is because the Lat and Lon of each Airport is stored in x-memory with the airport code tagged to it. Cheers, Geoff

 Re: HP41/42 Unit ConversionMessage #16 Posted by Steve Keeley on 28 Mar 2009, 3:44 p.m.,in response to message #1 by Egan Ford The HP 41 Thermal and Transport Science module added unit conversion capability to the 41. As I recall, you would place the number you wanted to convert into the X register and into the alpha register the string of units you wanted to convert from - to. ("ft*lbf/s - BTU/hr") and then hit a "convert" function. Unit checking/conversion was built into all the programs on it as well. If you opted for "Units" when running the program, then after prompting for the value, it would prompt for the units, which you would enter as an alpha string. It gave instructions for incorporating this capability into your own programs. As a chemical engineering major, this ROM was worth more than its weight in gold to me. The Petrloleum Engineering PAC also included this capability.

 Re: HP41/42 Unit ConversionMessage #17 Posted by Jeff Kearns on 28 Mar 2009, 6:47 p.m.,in response to message #16 by Steve Keeley The Machine Design Pac for the 41C series also has a similar unit conversion capability. 1. You key in the unit string in the Alpha register (it has a virtually unlimited set of unit conversions due to the ability to combine unit control characters *, /, -, and 1-9 with unit strings and equations). 2. Key in the numeric value to be converted 3. The program is executed with either FCON for forward conversion or BCON of backward conversion using the same unit conversion string. I find this program very handy and often more convenient for complex units than the RPL models - as long as you assign FCON and BCON to keys! I am amazed at the number of conversions that are possible using this program. Jeff

 Re: HP41/42 Unit ConversionMessage #18 Posted by Ángel Martin on 31 Mar 2009, 9:10 a.m.,in response to message #16 by Steve Keeley This thread reminds me of another item on my "ToDo list" - namely adding electrical units to the unit conversion libraries, as implemented on the different 41 modules... which I always found a very elegant and effective way to do it. With 82 units built-in, the Petroleum ROM has the more complete set, followed by the Thermal ROM (54) and the Machine ROM (42). Some are unique to one module but many are present on more than one. There are a "grand total" of 87 different units amongst the three. Here below are listed, FWIW - not that this adds any useful data to this subject though. Best, ÁM ACRE acre ANG angstrom API Degree API ATM Atmosphere BAR Bar BBL Barrel of petroleum BCF Billion Cubic Feet of Gas BTU British Thermal Unit C Degree Celsius CAL Calorie CM Centimeter CP Centipoise CST Centistoke D Darcy DAY Day DYNE Dyne ERG Erg F Degree Farenheit FT Foot FTH2O Foot of Water G Gram GAL Gallon (US) GALUK Gallon (UK) HP Horsepower HR Hour (mean solar) IN Inch INHG Inch of Mercury INH2O Inch of Water J Joule K Kelvin KCAL kilocalorie KG Kilogram KGF Kilogram Force KIP Kilopound Force KJ Kilojoule KM kilometer KMOL kilomole KPA kilopascal KSI KIP per square inch KT kilotonne KW kilowatt L liter LBF pound force LBM pound mass M meter MBAR milibar MCF thousand cubit feet gas MD millidarcy MG megagram MI mile MIC micron MIL 1/1000 inch MIN minute MJ megajoule ML milliliter MM millimeter MMCF million cubic feet gas MMHG millimiter of mercury MN meganewton MO month MOL(E) mole MPA megapascal MT megatonne MW megawatt N newton P(OISE) poise PA pascal PDL poundal PSF pound force per square foot PSI pound force per square inch R degree rankine S second SCF standard cubic foot SCM standard cubic meter SCMZ standard cubic meter 2 SLUG slug SPGR specific gravity to water ST(OKE) stoke T tonne THERM 10^5 BTU TON short ton TONUK long ton TORR torr UM micrometer W watt YD yard YR year OHM Ohm A Ampere V Volt FD Farad HY Henry TES Tesla GAUS Gauss CUL Culombe PFAD Pico Farad MHY Millihenry

 Re: HP41/42 Unit ConversionMessage #19 Posted by Walter B on 31 Mar 2009, 10:29 a.m.,in response to message #18 by Ángel Martin In your list are different sets of units. FWIW I tried to put some structure in: ```ACRE acre >IMP< ANG angstrom = 10^-10 M API Degree API ATM Atmosphere >OUTDATED< BAR Bar >OUTDATED< BBL Barrel of petroleum >IMP< BCF Billion Cubic Feet of Gas >IMP< BTU British Thermal Unit >IMP< C Degree Celsius CAL Calorie >OUTDATED< CM Centimeter = 1/100 M CP Centipoise = 1/100 POISE CST Centistoke = 1/100 STOKE D Darcy >IMP< DAY Day = 24 * 3600 S DYNE Dyne >OUTDATED< ERG Erg >OUTDATED< F Degree Farenheit >IMP< FT Foot >IMP< FTH2O Foot of Water >IMP< G Gram = 1/1000 KG GAL Gallon (US) >IMP< GALUK Gallon (UK) >IMP< HP Horsepower >IMP< HR Hour (mean solar) = 3600 S IN Inch >IMP< INHG Inch of Mercury >IMP< INH2O Inch of Water >IMP< J Joule >SI< K Kelvin >SI< KCAL kilocalorie = 1000 CAL KG Kilogram >SI BASE< KGF Kilogram Force >OUTDATED< KIP Kilopound Force >OUTDATED< KJ Kilojoule = 1000 J KM kilometer = 1000 M KMOL kilomole = 1000 MOLE KPA kilopascal = 1000 PA KSI KIP per square inch >IMP< KT kilotonne = 1000 TONNE KW kilowatt = 1000 W L liter = 1/1000 CBM LBF pound force >IMP< LBM pound mass >IMP< M meter >SI BASE< MBAR milibar = 1/1000 BAR MCF thousand cubit feet gas >IMP< MD millidarcy = 1/1000 D MG megagram = 1 million GRAM MI mile >IMP< MIC micron >IMP< MIL 1/1000 inch >IMP< MIN minute = 60 S MJ megajoule = 1 million J ML milliliter = 1/1000 L MM millimeter = 1/1000 M MMCF million cubic feet gas >IMP< MMHG millimiter of mercury >IMP< MN meganewton = 1 million N MO month MOL(E) mole >SI< MPA megapascal = 1 million PA MT megatonne = 1 million TONNE MW megawatt = 1 million W N newton >SI< P(OISE) poise >SI< PA pascal >SI< PDL poundal >IMP< PSF pound force per square foot >IMP< PSI pound force per square inch >IMP< R degree rankine S second >SI BASE< SCF standard cubic foot >IMP< SCM standard cubic meter SCMZ standard cubic meter 2 SLUG slug >IMP< SPGR specific gravity to water ST(OKE) stoke >SI< T tonne = 1000 KG THERM 10^5 BTU >IMP< TON short ton >IMP< TONUK long ton >IMP< TORR torr >OUTDATED< UM micrometer = 10^-6 M W watt >SI< YD yard >IMP< YR year = 365,2425 DAY OHM Ohm >SI< A Ampere >SI BASE< V Volt >SI< FD Farad >SI< HY Henry >SI< TES Tesla >SI< GAUS Gauss >OUTDATED< CUL Culombe >SI< PFAD Pico Farad = 10^-12 FD MHY Millihenry = 1/1000 HY ``` One can cut down this list massively by just taking into account the known meanings of milli, mega, kilo, centi etc. Units like ERG and DYN were already outdated when I studied some 35 years ago. Etc. Edited: 31 Mar 2009, 10:30 a.m.

 Re: HP41/42 Unit ConversionMessage #20 Posted by Ángel Martin on 3 Apr 2009, 2:29 a.m.,in response to message #19 by Walter B They may be "outdated" but sure enough are on the modules. Not sure that such a thing exist, anyway: units are units... they'll always be. Best, AM Edited: 3 Apr 2009, 5:52 a.m.

 Re: HP41/42 Unit ConversionMessage #21 Posted by Walter B on 3 Apr 2009, 11:25 a.m.,in response to message #20 by Ángel Martin When you take old modules, you'll get old units. Quite naturally.

 Re: HP41/42 Unit ConversionMessage #22 Posted by Garth Wilson on 28 Mar 2009, 8:11 p.m.,in response to message #1 by Egan Ford Quote:So, what do you all use for the 41 and 42? Just write tiny programs for the conversions you use and assign them to keys. One I use sometimes that's probably not in any module is wire diameter to wire guage and vice versa. Another is musical note to frequency and vice-versa. Edited: 28 Mar 2009, 8:12 p.m.

 Re: HP41/42 Unit ConversionMessage #23 Posted by Martin Pinckney on 29 Mar 2009, 5:55 p.m.,in response to message #1 by Egan Ford There is a Feet-Inches-Fractions Calculator for the HP-41CX here. © 1984 by Fred E. Lusk III, PE He alludes to "creating an HP-42S version, but never got around to finishing". Any thoughts on how hard would it be to modify this program to work on the 42s?

 Re: HP41/42 Unit ConversionMessage #24 Posted by Richard Garner on 30 Mar 2009, 1:31 a.m.,in response to message #23 by Martin Pinckney There is an HP 48S/G type unit conversion program for the Hp 42S on Thomas Okken's web site. I have thought about adding to it to make it more like the 48 version, but have not found the time to study what is being done in the program to add to it.

 Re: HP41/42 Unit ConversionMessage #25 Posted by Thomas Okken on 3 Apr 2009, 1:24 a.m.,in response to message #24 by Richard Garner The unit conversions in the Machine Design Pac (FCON, BCON), Petroleum Fluids Pac (CON, INCON), and the Thermal & Transport Science Pac (SI-, -SI) are all machine language functions, which makes it a bit of a pain to port them. I'm interested in adding some sort of unit conversion functionality to Free42; could someone point me to a list of officially sanctioned conversion factors? Note: for those of you who use Palm PDAs, there is a neat unit conversion utility called YAUC (as in Yet Another Unit Converter). It's not supported but I think it is still floating around on the 'net here and there. I use it regularly for U.S./SI conversions; it has a ton of units, but it doesn't deal with compound units like the RPL calculators do (or the above 41 pacs). Still, worth a mention.

 Re: HP41/42 Unit ConversionMessage #26 Posted by Ken Shaw on 3 Apr 2009, 10:27 a.m.,in response to message #25 by Thomas Okken You might look here: See appendix B.8 (p.45 ff.) There may be more help here:

 Re: HP41/42 Unit ConversionMessage #27 Posted by Thomas Okken on 3 Apr 2009, 5:29 p.m.,in response to message #26 by Ken Shaw That's perfect, thanks!!

 Re: HP41/42 Unit ConversionMessage #28 Posted by Egan Ford on 3 Apr 2009, 5:55 p.m.,in response to message #27 by Thomas Okken Thomas, So are you thinking of a non-42S functional enhancement to Free42? An evolution of the 42S? If so, I applaud your effort, and will formally ask for another enhancement: 41CX Time function support. How sweet, the 42SX! Thanks. Edited: 3 Apr 2009, 5:59 p.m.

 Re: HP41/42 Unit ConversionMessage #29 Posted by Thomas Okken on 3 Apr 2009, 7:59 p.m.,in response to message #28 by Egan Ford Hi Egan! That sounds like a good addition -- I'll put it on my list. The one I'm *really* looking forward to adding is iPhone accelerometer access. :-) - Thomas

 Re: HP41/42 Unit ConversionMessage #30 Posted by Walter B on 4 Apr 2009, 4:03 a.m.,in response to message #29 by Thomas Okken Quote: The one I'm *really* looking forward to adding is iPhone accelerometer access. Is this really an accelerometer or is it just a position switch?

 Re: HP41/42 Unit ConversionMessage #31 Posted by Egan Ford on 4 Apr 2009, 11:33 a.m.,in response to message #30 by Walter B Yes, it is a 3 axis accelerometer.

 Re: HP41/42 Unit ConversionMessage #32 Posted by reth on 5 Apr 2009, 6:12 a.m.,in response to message #29 by Thomas Okken So there is a wish list? I'd add displaying flags 0-4 as in 41 and fraction input as in HP35s. Cheers

 Re: HP41/42 Unit ConversionMessage #33 Posted by Thomas Okken on 6 Apr 2009, 1:48 a.m.,in response to message #32 by reth Hmm, well, I can add those to my to-do list, but whether they will get done any time any time soon is another matter. The problem with fractions is that that requires adding a new data type, and that affects just about everything. Huge, huge amount of work. You're probably better off using a 50g instead. Adding annunciators to the display is a lot easier, but it will require changes to all the skins. At least those changes are a lot easier than the changes that would be needed to support a 4-line display...

 Re: HP41/42 Unit ConversionMessage #34 Posted by reth on 6 Apr 2009, 2:23 a.m.,in response to message #33 by Thomas Okken Thanks Thomas, well I sort of guessed so but could not resist to mention it. Never mind.Cheers and keep up the good work!Reth

 Re: HP41/42 Unit ConversionMessage #35 Posted by Paul Dale on 5 Apr 2009, 4:49 p.m.,in response to message #25 by Thomas Okken I've always liked this site. Not so much for accuracy as the comprehensive nature of weird units :-) - Pauli

 Re: HP41/42 Unit ConversionMessage #36 Posted by Fred Lusk on 30 Mar 2009, 2:05 a.m.,in response to message #23 by Martin Pinckney Martin.... It's still on my "to-do" list :-( Actually, several years ago I nearly completed the re-write for the 41CX version that I mention in the program description. I just haven't had time to do the last bit of checking, polishing, and documenting. The new version will more easily port to the 42S than the original because of reduced reliance on XFUNCTIONS. However, a new granddaughter and other things in life have pushed this back on the priority list. I don't do FIF calculations that much anymore, but for day-to-day use I wrote an Excel spreadsheet that allows me to enter as many dimensions as I need. The spreadsheet includes a multiplier for each dimension so I can do things like x*A + y*B ... One of these days.... Fred

 Re: HP41/42 Unit ConversionMessage #37 Posted by Martin Pinckney on 30 Mar 2009, 11:30 a.m.,in response to message #36 by Fred Lusk Quote: Â© 1984 by Fred E. Lusk III, PE It's still on my "to-do" list :-( Fred, Wow, you are worse than me... will I live long enough to make a dent in my To Do List? I still need to do FIF calculations frequently. I regularly just do them by first mentally converting to decimal feet, if precision is not so important. Or if it is, I use the 32sii fraction mode for the inches, then convert back to feet. Now that I finally obtained a 42s, I would like to make use of its power with a program that like the one you wrote. Of course, if I was really practical, I would just buy a Calculated Industries calculator. But it wouldn't be an HP... Anyway, thanks for responding, that was a nice surprise.

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