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Subject: comp.sys.hp48 FAQ : 1 of 4 - Common Questions

This article was archived around: 14 April 2000 22:00:01 GMT

All FAQs in Directory: hp/hp48-faq
All FAQs posted in: comp.sys.hp48, comp.sources.hp48
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Archive-name: hp/hp48-faq/part1 Last-modified: 4/14/2000 Version: 4.62 Posting-Frequency: Every 14 days or so
New in v4.62 o Added another alternate solution to Compact Data Storage problem o Gave proper credit to Dave Hicks for his Q/A on RPN -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 HP48 Frequently Asked Questions List (FAQ) Andre Schoorl <aschoorl@engr.uvic.ca> v4.62, 14 April 2000 Answers to Frequently Asked Questions about HP48 calculators ______________________________________________________________________ Table of Contents 1. Introduction 1.1 Overview 1.2 This FAQ in Other Formats 1.3 Translations of this FAQ 2. Miscellaneous Questions 2.1 I'm a novice, and I have some questions. Where should I start? 2.2 What Usenet Newsgroups are there for the HP48? 2.3 What are some good sites for the HP48? 2.4 Are there any good WWW links for HP48 stuff? 2.5 Is there an HP48 IRC Channel? 2.6 How can I search for a specific HP48 file? 2.7 What are good places to buy HP48's and accessories? 2.8 What happened to EduCalc? 2.9 Are there any CD-ROMs with HP48 software? 2.10 Where can I find HP conference videotapes? 2.11 Are there any HP48 Emulators? 2.12 How can I make a dump of my HP48 ROM? 2.13 Is the HP48 Allowed on SATs, AP, or ACT Tests? (U.S.) 2.14 What is the HP49G? 2.15 How does the HP48 compare with other calculators? 2.16 What is the Universal Font Library (UFL)? 2.17 What are the best alternate editors? 2.18 Are there any PC fonts for the HP48? 2.19 Is the HP48 serial number available in memory? 2.20 What is the format of the HP48 serial number? 3. Questions about ROM versions 3.1 What does the SX/GX have that the S/G doesn't? 3.2 What is the difference between the HP48 G/GX and the HP48 S/SX? 3.3 What is the HP48 G+? 3.4 How can I tell what ROM revision I have? 3.5 What bugs exist in the various versions of the HP48? 3.6 What is new with the revision "J" ROM? (S/SX) 3.7 What happened to ROM revisions G, H, I, O, and Q? 3.8 Can I upgrade my HP48 S/SX? 3.9 Can I upgrade my buggy GX to the latest ROM revision? 3.10 What's the latest ROM version? 3.11 Why would I buy a S/SX rather than a G/GX? 4. Questions about the Operating System and Using the HP 4.1 How do I find the checksum of an object? 4.2 I typed RULES on my G/GX and got a crossword puzzle! 4.3 Why does my HP48 occasionally "freeze" for a moment? 4.4 What do I do if my HP48 locks up? 4.5 My HP48 seems to take longer to turn on and off. 4.6 What are all the different ON-KEY combinations? 4.7 What are the different interactive self-tests? 4.8 Why do I get an ESD error when I check my batteries with the self test? 4.9 I can't account for some of the RAM in the HP48! 4.10 What are the best methods for installing and removing libraries? 4.11 How can I attach large libraries? 4.12 What are those little numbers near the top of my screen? 4.13 Can I use my HP48 as a remote control? 4.14 Can the HP48 be used as a DTMF phone dialer? 4.15 How can I run a program on warmstarts and/or power-up? 4.16 I could speed up my HP-28S. How can I speed up my HP48? 4.17 What is the hidden directory and how do I access it? 4.18 How can I recall one object from a memory archive? 4.19 Are there any key combinations that aren't in the manual? 4.20 How do I find out about commands not in the GX manual? 4.21 How can one delete (or purge) an entire directory? 4.22 How does binary wordsize affect my calculations? 4.23 Can I add my own equations to HP's Equation Library? 5. Questions about Math, Plotting, and Equations 5.1 Why does (1/3)*3 equal 0.999999999999? 5.2 Why does my HP say that 0 to the power of 0 equals 1? 5.3 What is RPN? 5.4 Why did HP use RPN in their calculators? 5.5 Is there an alternative to calculating in RPN? 5.6 Why do I get unexpected values when I add temperatures? 5.7 How can I add my own units? What's the 1_? unit for? 5.8 I want `pi' to be a numeric value, not a symbol. 5.9 What tricks are there for manipulating matrices? 5.10 Can I make my HP graph any faster? 5.11 How do I plot inequalities? 5.12 How do I take the logarithm of a base other than 10 or e? 5.13 How do I solve quadratic equations? 5.14 Why do I get a complex answers for roots of negative numbers? 5.15 Why doesn't '(-8)^(2/3)' give me the right answer (4)? 5.16 How do I solve polynomials? 5.17 How can I do statistics for grouped data? 5.18 How do I generate a function table? 6. Questions about cards, data transfers, batteries, and hardware 6.1 My HP48 seems to making a high pitched noise. 6.2 Can I upgrade my S or G to more than 32K ram? 6.3 Can I add a lithium battery backup? 6.4 How can I get/build a cable for my HP48? 6.5 HP seems to offer two link kits with different prices. 6.6 Is there any communications software available? 6.7 Why doesn't the I/R port work farther than a few inches? 6.8 Can my HP48 talk to my HP100LX via Infrared? 6.9 Can I use my HP48 to communicate with IrDA devices? 6.10 Can I print to a LaserJet printer with an HP48? 6.11 I downloaded a program but all I get is "HPHP48-..."! 6.12 What is the structure of HP48 ASCII headers? 6.13 Why do Kermit transfers seem to get slower? 6.14 Why does XRECV not work sometimes? (GX) 6.15 Additional Tips on Transfers 6.16 What do the funny symbols in this document mean? 6.17 What are the pinouts for the HP48 serial connector? 6.18 Is there any information on interfacing to the HP48? 6.19 How can I transfer programs/data from my HP-28S to my HP48? 6.20 Can I use rechargeable batteries with the HP48? 6.21 How can I tell, from within a program, if the battery is low? 6.22 I lost the information on my RAM Card when I changed the battery! 6.23 Why do I get an "Invalid card data" error when I merge a RAM card? 6.24 I've heard about other manufacturer's RAM cards. Will they work? 6.25 How does RAM card locking work? 6.26 What are the advantages and disadvantages of covered ports? (GX) 6.27 Why does the HP48 display flicker slightly? 6.28 I broke the LCD screen - is there an easy way to get another? 6.29 How can I protect my LCD? 6.30 Is there a rigid (protective) case for the HP48? 6.31 Can I use my Amateur Radio with my HP48? 7. Questions about programs 7.1 Where can I get programs and information for the HP48? 7.2 What are the Goodies Disks and where do I get them? 7.3 How do I get access to the HP Calculator BBS? 7.4 What are files that end with ".zip", ".Z", ".gz", or ".bz2"? 7.5 What is a "ship" file? 7.6 What is the ASC format and how can I use it? 7.7 What is the HYDE library, and how do I get rid of it? 7.8 What is the Minehunt game, and how do I use it? 8. Questions about programming and advanced user functions 8.1 I've heard the names RPL, Saturn, STAR, GL etc... What are they? 8.2 Is there a C compiler for the HP48? 8.3 Why do SysRPL programs run faster than UserRPL programs? 8.4 What is a good reference for learning SysRPL and ML? 8.5 Can I make my own libraries? Can I split others? 8.6 How do I know what library ID number to use for my program? 8.7 What information is there on the internals of the HP48? 8.8 Where can I get some programming development tools? 8.9 I know UserRPL. How do I get started in SysRPL? 8.10 Are there any viruses for the HP48? 8.11 How do I store fields of variable length effectively? 8.12 What is "Vectored Enter", and how do I use it? 8.13 What is "WSLOG"? 8.14 What are SYSEVALs? 8.15 What are some useful SYSEVALs? 8.16 What are LIBEVALs? 8.17 What are some useful LIBEVALs? (GX) 8.18 What is the format of a GROB object? 8.19 What is the AUR and what information does it contain? 8.20 What is the syntax for INFORM, CHOOSE, and MSGBOX? (GX) 8.21 How do I put checkfields in my INFORM menus? 8.22 What is the syntax for the INPUT command? 9. Appendix A: Various Useful Functions 9.1 ASC Functions 9.2 OBJFIX 9.3 FIXIT 9.4 LASTX 9.5 Compact Data Storage 9.6 HP82240B Printer Codes 10. Appendix B: GX Specific Information 10.1 What's new in the HP48 G/GX? 10.2 Examples of INFORM, CHOOSE, and MSGBOX 10.3 Some useful LIBEVALs 11. Appendix C: Details of Bugs 11.1 The EquationWriter Bug 11.2 Rotation Rate to Angular Frequency Conversion Bug 12. Appendix D: Hardware Additions 12.1 How to Make a Serial Cable 12.2 Using a modem with the HP48 12.3 Additional Information on the HP48 and RS-232 12.4 Using Non-HP RAM Cards 12.5 Where can one obtain third party RAM cards? 13. Appendix E: Where to get HP48 Programs 13.1 Best Programs and Where to Get Them List 13.2 Other Web / FTP Sites 13.3 FTP by Electronic Mail 13.4 Bulletin Boards with HP48 Programs 13.5 HP Goodies Disks 14. Contributors ______________________________________________________________________ 1. Introduction This FAQ is maintained by Andre Schoorl <aschoorl@engr.uvic.ca> It was previously maintained by Keith Maddock, and was originally compiled by Darryl Okahata. Many thanks to both for their time and contributions! I rely on your input in order to keep this FAQ up to date. If you have any suggestions or updates, feel free to mail them to me. If you have a correction or suggestion to make, please include the name of a specific question rather than its number as the number is automatically generated and can change between versions. 1.1. Overview The purpose of this FAQ is to provide answers to commonly asked questions about the Hewlett Packard HP48 family of scientific calculators. This list contains information which has not necessarily been verified, and is not guaranteed to be correct. It has been compiled from various postings in the newsgroups comp.sys.hp48 and comp.sys.handhelds, as well as other sources. In particular, some parts were taken from older HP48 SX "FAQ Lists". For some questions, there may be different answers for each calculator (G/GX vs. S/SX). In this case S/SX specific information is preceeded by an "SX:" on the left margin of the first line of each S/SX specific paragraph. G/GX information is denoted by a "GX:" in the same place. If a paragraph has no notation, then it is valid for all versions. 1.2. This FAQ in Other Formats This document was made using the SGML-Tools (Standard Generalized Markup Language) package and is available in ASCII, HTML, and PostScript versions. All versions come from the same source, and are thus updated simultaneously. The URL for the HTML version is <http://www.engr.uvic.ca/~aschoorl/faq/>. The other formats are also available here in separate zip files. The PostScript version is formatted for letter size paper, but it is also possible to create PostScript for legal size paper. Furthermore, DVI, LaTeX, Lyx, Info, and RTF forms of the FAQ are also possible. Since it is impractical to provide all of these formats, the SGML source is available in case anyone wants to create one of these formats on their own. Text only versions of the FAQ will be posted to the newsgroup comp.sys.hp48 as needed (usually every two weeks). Also, remember that all official FAQs (including this one) are mirrored at <ftp://rtfm.mit.edu/>. Furthermore, it is posted to comp.answers and news.answers. I will sign all text versions with PGP (Pretty Good Privacy) using the following key for authenticity, and provide MD5 Checksums for the remaining files. You can get a copy of this public key from the keyserver at <http://pgpkeys.mit.edu/>, or through the URL above. Type Bits KeyID Created Expires Algorithm Use sec+ 1024 2CFAA0BB 1997-06-21 ---------- DSS Sign and Encrypt sub 2048 F940E148 1997-06-21 ---------- Diffie-Hellman uid Andre P. Schoorl <aschoorl@engr.uvic.ca> Alternatively, you can download the FAQ at one the following locations: North America: o <http://www.hpcalc.org/docs/faq/> Europe: o <ftp://ftp.stud.fh-heilbronn.de/pub/systems/hp48/incoming/> o <ftp://ftp.stud.fh-heilbronn.de/pub/systems/hp48/info/FAQ/> 1.3. Translations of this FAQ These translations may not be as up to date as the main FAQ, but should still be useful for international users who are more comfortable with their native language. Portugese: o <http://members.tripod.com/~area48/> by Carlos Alberto Marangon Spanish: o <http://www.alumnos.utfsm.cl/~aarrieta/hp48.html> by Alejandro Arrieta Rios and Guido Carvajal 2. Miscellaneous Questions 2.1. I'm a novice, and I have some questions. Where should I start? Start by perusing the HP48 manuals. You'd be amazed how many questions can be answered if you read the manuals. SX: Earlier HP48 S/SX manuals came in two volumes. The first volume dealt with operating instructions, and the second volume dealt with programming. Later HP48 S/SX manuals combined these two volumes into one. GX: HP48 G/GX models come with a one-volume owners manual that covers all of the non-programming aspects of the calculator. An Advanced User's Reference (AUR) is available that covers programming aspects. It is highly recommended. They also come with a Quick Start Guide, a guided tour of some of the HP48's capabilities. Also, look over the section "Answers to Common Questions", in Appendix A of the manual. If you have a two-volume manual, it will be in volume II. 2.2. What Usenet Newsgroups are there for the HP48? comp.sys.hp48 Primary HP48 newsgroup. comp.sys.handhelds Occasionally, HP48 information is posted to this newsgroup. comp.sources.hp48 This newsgroup has been dead for years, but was once a moderated group for HP48 Programs. es.comp.sistemas.hp48 Is a spanish newsgroup for the HP48. Articles posted to the newsgroup comp.sys.hp48 are archived at <ftp://wuarchive.wustl.edu/usenet/comp.sys.hp48/>. Articles are archived by year and month, with a general index covering approximately the past two years. The AltaVista search engine at <http://www.altavista.digital.com> also accesses these archives (for a Usenet search), and automatically uncompresses any relevant articles you may select. DejaNews <http://www.dejanews.com/> is another fast Usenet archiver/searcher, with many extra features such as Author profile and article search. The only drawback is that it strips attachments from posts (uuencode, MIME) to save space. Another good way to find HP48 posts is through one of the various search engines available on the web. For example, Netscape, Lycos, and Magellan and others all seem to be able to find Usenet articles on the HP48. The search may even find articles that have long since expired from your local news server! 2.3. What are some good sites for the HP48? Many HP48 programs can be found on the following FTP sites: o <http://www.hpcalc.org/> o <ftp://ftp.hp.com/pub/calculators/> o <ftp://wuarchive.wustl.edu/systems/hp/hp48/> For a list of other HP48 FTP sites, see Appendix E-2. 2.4. Are there any good WWW links for HP48 stuff? Rather than list out a long list of HP48 related WWW resources, here is a single HP48 Page which contains links to other HP48 pages: o <http://www.gmi.edu/~madd0118/hp48/> Another well maintained site is <http://www.hpcalc.org/>. 2.5. Is there an HP48 IRC Channel? Yes, try connecting to an EFNet server and join channel #hp48. Many of the most knowledgeable HP48 users frequent it, making it a nice place to get your questions answered. There are even two IRC robots (hp48b and RPL) on the channel. The following information will get you started: First, download an appropriate IRC client. Collection of clients are available at <http://www.irchelp.org> or <ftp://ftp.undernet.org/> Second, find a working EFNet server and join #hp48. A list of servers is given at <http://www.irchelp.org/irchelp/networks/servers/efnet.html> 2.6. How can I search for a specific HP48 file? If you know the all or part of the filename of an HP48 program, you can use the proper Internet search services instead of bothering all the readers of the newsgroup. The following server is especially good, it seems to find HP48 files from just about anywhere. <http://ftpsearch.ntnu.no/ftpsearch> 2.7. What are good places to buy HP48's and accessories? X-Philes CD-ROM: There is a CD-ROM called the X-Philes on the market that includes many HP48 files. See the next question for more details. Office Max: Toll Free: (800) 788-8080 Wholesale Products: This is another company on the web that sells HP handhelds, including the HP48. Their address is <http://www.wholesaleproducts.com> or you can mail inquiries to <wholesal@shore.net> The Mall At Wholesale Products 400 West Cummings Park Suite 1725-122 Woburn, MA 01801 781-438-8622 (Telephone, 9 a.m. - 5 p.m. Boston time) 781-438-8307 (FAX, 24 hours a day, 7 days a week, from anywhere) E-mail: wholesal@shore.net Web: North America: o <http://www.wholesaleadvantage.com/hpcalcs.html> o <http://www.waterw.com/~jake-s/handyclc.htm> o <http://www.dvtg.com/> o <http://www.smi.com/> o <http://www.tdsway.com/> o <http://www.ramss.com/> o <http://www.chotkeh.com/> o <http://muffet.com/samsoncables/> o <http://www.calculatorsinc.com/> Europe: o <http://members.aol.com/weidatec/> o <http://www.Digitalis.de/> o <http://stolte-edv.com/> o <http://home.t-online.de/home/FFFFF/> o <http://www.bbm.e.se/> o <http://www.geocities.com/Eureka/Enterprises/3190/> Others: Global Connections Incorporated (formerly Connection Point, Inc.) 50 South River Street, Suite 105, Janesville, WI 53545 Tel: (608)-752-9548 or (608)-752-1537 Oxford Educational Supplies (U.K.) Tel: 01869 343369 (mail order) Notes: No shipping charge for within U.K. Spectrum Office Equipment 22 Stokes Croft Bristol (U.K.). 0117 9428278 Best (Western U.S., used to be La Belles) 1-800-950-2378 Calculators Inc., Minneapolis, MN, U.S. (612) 866-8908 Carrington, (800) 982-3731 J&R Music World - Computer World 1-800-221-8180 Office Depot (U.S. and Canada) Service Merchandise (East Coast U.S.) 2.8. What happened to EduCalc? EduCalc, which had been one of the best sources for HP48's and accessories, went out of business on 31 December 1997. 2.9. Are there any CD-ROMs with HP48 software? Yes, there are a few CD-ROMs with HP48 software I know of: HP48 Archive CD: The most current set of files at <http://www.hpcalc.org/> is always available on a custom burnt CD-R. Details are at the same URL. X-Philes: The X-Philes is a CD-ROM made by Synchron Data that contains most HP48 programs to date. All together the CD-ROM contains over 21,000 files and more than 620 MB of information, mostly zipped. The HP48 sections contain 3194 files and make up 38.5 MB of the total. This includes all of the Goodies disks (aka Horn disks) 1 through 10. There are also files for HP95, Psion, TI-82 and TI-85 calculators, as well as information and programs on: Jokes, Star Trek, Sports, Midi, History, Strange files, Conspiracy, Law and Business, Internet & Networks, Atari, BBS- Systems, Hardware, Computers, 3D-Objects, Anarchy, Hacking, Movies, X-Files, Music, Magazines, Science, UFO and Aliens, Occult, Security & Privacy, Amiga, Cyberspace, Subcultures, Radio, Virus hunting, Survival, Phreaking, PC utilities, Game cheats and levels, and Programming. The CD comes with easy to use Windows software for browsing and searching for keywords. This software contains an upload feature that allows you to transfer programs directly to your HP (or modem) using X-Modem. More information on obtaining the X-Philes CD-ROM is at: WWW: <http://www.algonet.se/~synchron/> E-Mail: <dt93tn@pt.hk-r.se> Regular Post: Synchron Data Tranbarsvagen 25:14 372 38 Ronneby Sweden SHAREWARE Volume 1 for Hewlett-Packard: There is a CD-ROM by a German company called Yellow Computing named SHAREWARE Volume 1 for Hewlett-Packard. It sells for DEM 49.80 (U.S.$ 34.00), and is distributed from: Yellow Computing Phone +49 7136 951143 Computersysteme GmbH Fax +49 7136 951111 Postfach 1136 D-74173 Bad Friedrichshall Germany This is the German company which offers PC <-> HP-48 transfer cables together with Windows software for transfering files (the "Transfile Win 48" package). The CD-ROM comes with a 16 page booklet in German and English which shows how to use the included Windows 3.1 transfer program (with program and catalogue files in both languages). It's sampled in Aug 95, pressed Oct 95 and contains about 85 MB of software for the HP48 SX/GX, 95LX, 100LX and 200LX; the Horn disks 1 through 9, and about 710 additional HP-48 programs in the 9 categories: Animation, Data, Games, Graphic, Programming, Maths, Memory, Science, Utility and Communications. It also has about 200 other unsorted, compressed HP48 files. Decompression software is included. It's not an ISO CD-ROM, since it contains directories and files, whose names contain exclamation marks, hyphens and dollar signs. Handheld HP CD-ROM Library: This collection contains 13,611 files for a total of 314 MB of compressed software for HP Handhelds. The principal groups of this collection are: 1. HP28C/S (up to 2.5 Mb) Applications, Games, Utils, Docs. 2. HP48S/SX (up to 48 Mb) Applications, Business, Chemistry, Communications, Emulators, Games, Graphics, Math, Physics, Programming, Sound, Time, Utils, Docs. 3. HP48G/GX (up to 40 Mb) Applications, Business, Chemistry, Communications, Games, Graphics, Math, Physics, Programming, Sound, Time, Utils, Docs, Sys-RPL. 4. HP38G (up to 2 Mb) Applets, Applet Development Kit, Docs. Platform files total 30 MB, additional documentation is 18 MB, various collections including the Horn disks and SysRPL collection total 106 MB, and finally 58 MB of information from HP groups around the world. For more information, orders, and pricing send e-mail to <carles@idgrup.ibernet.com> Ingenieur Professional CD ROM This is another German CD issued by Harald Kresin and Franz Lorenz. It contains roughly 67 MB of HP Software. Their web page is <http://home.t-online.de/home/05713201317> and their e- mail is <05713201317@t-online.de; Their address is Franz Lorenz Pocketcomputer & Zubehoer Bruchstr. 51, D-32423 Minden Germany 2.10. Where can I find HP conference videotapes? Jake Schwartz maintains a list of videotapes of HP handhelds meetings / demos / conferences going back as far as 1986 and the intro of the HP18C. They are available at relatively low cost to anyone who is interested. The URL is <http://www.waterw.com/~jake-s/video.htm>. 2.11. Are there any HP48 Emulators? A fully functional HP48 emulator by Eddie Dost called "x48" is available. It runs in X-Windows on any Unix based operating system like Linux or Solaris. However, it requires a ROM dump of an HP48 to run. Of course, due to copyright laws such a ROM dump cannot be distributed with the x48 package. Therefore, you must be the proud owner of an HP48 (S/SX or G/GX) in order to create your own ROM dump. The emulator will look and act either like a S/SX or a G/GX, depending on what type of ROM dump you give it. Further instructions are contained in the x48 package itself. The latest version of x48 is available at <http://www.hpcalc.org/pc/emulators/> There is also a freeware emulator for Windows called Emu48. It is written by Sebastien Carlier, and runs under either Windows 95 or NT. It offers many exciting features, including fast speed, saving of memory, direct loading of files onto the stack, a greatly customizable interface, and support for ports through 33. It supports both S/SX and G/GX ROM dumps, and comes with a "RomDump Wizard" to help you create one. The binaries and full C++ source code, distributed under the GNU Public License, as well as more information, are available at <http://www.epita.fr:8000/~sebc/Emu48/>. There are also a series of "Unofficial Service Packs" available at <http://privat.swol.de/ChristophGiesselink/>. An emulator for the HP38, based on Emu48 has also been created. It is available at <http://www.epita.fr/~avenar_j/hp/38.html> There is also an HP48 S/SX/G/GX Emulator for Amiga computers called Alcuin. See <http://www.cis.tu- graz.ac.at/home/schupfer/Alcuin/index.html> for more information. 2.12. How can I make a dump of my HP48 ROM? Emulators for the HP48 generally require an image of your HP48's internal ROM, also known as a "ROM Dump". Currently the best program to make a dump of your ROM is ROMDump Wizard by Christoph Giesselink. It is available at <http://privat.swol.de/ChristophGiesselink/> 2.13. Is the HP48 Allowed on SATs, AP, or ACT Tests? (U.S.) From: Jack Levy The S/SX/G/GX are allowed on the SAT's. The S/SX/G/GX are allowed on the SAT II Math IIc test, but no calculators are allowed on any of the others. The S/SX/G/GX are allowed on the AP Calculus exam. However, only the S/SX are allowed on the AP Chem and AP Physics exams because the G/GX has the built in equation library. Update from: Sandler Rubin As of 1996, HP 48G calculators are allowed on the physics and chemistry APs, but only for the free response section. All calculators are now banned on the multiple choice sections on the physics and chemistry APs. As for calculus, the HP 48G is allowed on one half of the multiple choice and all of the free response. The other half of the multiple choice on the calculus test must be completed without any calculator. These changes have occurred because the AP tests are now more conceptual and depend less on pure "number-crunching". In the free response sections of the chemistry and physics tests, lists of important physics equations are include for student use which basically make the HP 48G EqLib redundant. Update from: John Goerzen After a lot of discussion with Candance Noble <Noble@act.org> of ACT, they changed their policy to allow it only if the IR port is covered with opaque tape. Their response follows: This notice is in response to questions ACT has received about acceptable calculators. Please pass this clarification on to others. Effective Fall 1996, examinees may use calculators on the ACT Assessment and PLAN Mathematics Tests. Students taking the ACT Assessment should review page 3 of Registering for the ACT Assessment. Students taking PLAN should review page 4 of the Planning Guide for Students and Parents. All makes and models of calculators are acceptable -- including programmable calculators and hinged calculators with mathematical formulas printed by the manufacturer on the inside flap -- provided the calculator does not have any of the unacceptable features specified in the ACT publications noted above and further clarified below. Examinees using unacceptable calculators will be dismissed from testing. The following information is provided to help students select an acceptable calculator if they choose to use one on the ACT Assessment or PLAN Mathematics Test. POCKET ORGANIZERS, HANDHELD OR LAPTOP COMPUTERS All such devices are prohibited. ELECTRONIC WRITING PADS/PEN INPUT DEVICES Such models are readily recognizable due to the pen or stylus used to input data. All such devices are prohibited. The term QWERTY derives from the first six letter keys (left to right) of the top row of typewriters, personal computers, most handheld and laptop computers, pocket organizers, and specialized calculators. All models with QWERTY keyboards are prohibited. PAPER TAPE If a calculator has a feature that provides paper output, the paper must be removed to make the calculator acceptable. NOISE Calculators that have a "talking" or audio feature are acceptable in a group testing situation only if the sound feature has been turned off. WIRELESS COMMUNICATION Calculators that can communicate (transfer data or information) wirelessly with other calculators can be recognized by the "window" or infrared data port on the top edge of the calculator, similar to one on a television remote control. Such calculators are acceptable only if the wireless transfer capability is disabled by placing opaque material (such as masking tape) over the infrared data port. POWER CORD If a calculator can run on either battery or electrical cord, the electrical cord must be removed to make the calculator acceptable. 2.14. What is the HP49G? On May 21st, 1999, at the OpenHP Conference in Paris, France, Hewlett Packard announced the HP49G graphic calculator. The following information comes from Jean-Yves Avenard of HP's ACO (Australian Calculator Operation). Hardware o 512KB of RAM o 2MB of flash memory (1MB used for upgradable ROM, 1MB available to user) o 4MHz Saturn CPU o 131x64 pixel screen (black instead of blue, so higher contrast) o 51-key keyboard with tactile rubber keys o This is not the same type of keyboard as the HP48 has but it is still an HP quality keyboard. Rubber keys don't always mean bad quality, as there are a lot of mechanical parts to make a keyboard. o The feeling is extremely similar to the HP48 keyboard. Do you really think that HP could let a new product go out of its doors with a keyboard that will break after 6 months? o New keyboard layout - a user friendly keyboard that incorporates the strengths of the existing RPN keyboard layout and the more familiar algebraic style keyboard layouts on the HP 38G, TI-83 and TI-89. o Metallic blue case with a translucent blue-tint slide-on cover. You can put it in the HP48's case if you prefer a soft case. o No IR, but an HP49<->HP49 cable is provided (adapter included for connection to HP48). There were problems in some countries with some teachers fearing the HP48 would be used to cheat because of the IR port. o RS-232 serial port with Kermit (binary, ASCII) and Xmodem (128 checksum, 1K, 1K CRC) running at 9600 bps (15360 bps internally, but no PCs support that speed). o Any unit may be directly connected to a data-logger, overhead projector, a personal computer or another HP 48G Series or HP 49G graphing calculator. o The hardware is not expandable, but the ROM can be software- upgraded and there is plenty of memory, so this should not be a problem. Memory Management o Even though the Saturn can only access 512K of memory, a new bank switching routine is used, in addition to absolute addresses, making it much faster. o The user sees three ports of memory: Internal System RAM (256KB, port 0), Extended RAM (256KB, port 1), and Flash User ROM (1MB, port 2). o The system will manage how to copy your files for you, so there is no need to get lost in a bank. Software o Step-by-step solving option that enables you to learn how to get the right answer numerically or symbolically. o The most complete built-in Computer Algebra System (CAS) currently available on a calculator for fast, advanced symbolic manipulation and solving. o Imagine an HP48 with Erable and ALG48 plus everything that is missing. Now speed it up so it can compete (and be faster) than anything else on the calculator market. That's the HP49's CAS. o Inferential and Descriptive Statistics (suitable for Advanced Placement and College/University level statistics). o A fast, flexible and intelligent Editor for isolating, editing, manipulating and evaluating text, equations, expressions, sub- expressions, programs and graphs. o Input and Output Customization - choose between "textbook" form (pretty print), algebraic and RPN input and "textbook" and algebraic output in various font styles and sizes. o When you first boot the machine, it's an algebraic machine. If you don't like algebraic mode, simply press Mode, select "RPN" and that's it. You're back to the HP48 Reverse Polish Notation mode forever and ever (at least until you clear the memory or manually switch back to algebraic). It works EXACTLY like the HP48, but faster. o Between 10 and 100 times faster than the existing HP 48G Series o The OS has been completely rewritten, mainly in assembly language, so nearly everything that was slow on the HP48 works faster, including input forms, choose boxes, stack display, command line, file manager, etc. When I say faster, I mean MUCH faster. The HP49 is even faster than an HP48 with the MetaKernel running in it. o There is no longer a built-in equation library but the constants library remains. o Do you think the 4MHz CPU is slow? The 3D real-time plotter can draw 6 frames (for a 14*14 points matrix) per second... It's faster than any current competitors! You can rotate in real time over the X axis, Y axis and even the Z axis. Programming o Provides four programming languages: 1. HP Basic: like a hybrid between RPL and Basic. This does not have GOTO and cannot really be called Basic, as it looks like the HP38G's programming language. Example code: FOR(i,1,100) DISP(i,1); IF I+1-5==50 THEN DISP("Hello World",2) ELSE DISP("I'm off",2) END STEP(1) 2. User RPL: Just like the HP48's built-in language. To reuse a User RPL program from an HP48, send it to the 49 using ASCII Kermit. 3. System RPL: Development software, including disassembler, built into ROM but not supported. 4. Assembly language: Development software, including disassembler, built into ROM but not supported o Grayscale support (in ASM as well as System RPL). All System RPL graphic routines work on grayscale graphics. o Vectorized Interrupt System (add your own interrupt handler) o To run an HP48 application on the HP49, just recompile it. It will probably run faster, too, especially if it uses the GUI. o Entry points have moved to make the ROM easier to maintain, but programs will still be compatible at the source code level. The HP49 is the most powerful calculator ever announced at any time. It works in two ways: one fully compatible with the HP48 series, including RPN but faster, and the other algebraic, easy for users of other calculator brands to learn to use. Although you may not agree with some of the specifications above, please wait until you touch it before complaining. After all, the HP49 was developed by HP48 users and tested by HP48 users! For more information, visit the HP Calculator Archive at <http://www.hpcalc.org/> 2.15. How does the HP48 compare with other calculators? From: Chin-Yu Hsu <chinyu@voyager.bxscience.edu> What are the differences between the HP48 and the TI? Before listing the differences, I wish to let you know that the HP48 has much more functionality than the TI's. However, these additional functions are usually of no help in high school than the TI. Instead, they are only helpful in college depending on the course you take. The TI is probably a better choice on tests in high school since it is easier to use (to most people) and does calculations faster (because it offers speed at the expense of the higher precision of the HP48). Please note that the HP also offers the HP38 which is more comparable to a TI-82. Also, you should realize that if you want support for the graphing calculator, the HP48 is the one to get. Although you can get support from Texas Instrument (by phone and by web), and also by teachers in school, you can get support for the HP48 from a larger group in the world. There are far more web sites related to the HP48 than to the TI graphing calculators. Also, the HP48 has its own newsgroup and its own IRC channel (usually up 24 hours a day and maintained by a bot that can send you programs at your request). Please note that although the calculation and graphing capabilities may not be available for a particular calculator, you can usually download a program that extends such a capability to it. If you find that part of the information below is incorrect, please tell me about it. You may need to provide additional proof, if I am unable to confirm it. Any additional information on the TI-92 is helpful because much about it is still a mystery. General Differences: Calculator HP38 HP48(2) TI-82(3) TI-85 TI-92 List Price(4) $109 $135/$265 $125 $135 $250 Available Mem.(5) 32KB 32/128KB 28.2KB 28.2KB 70.0KB Batteries Req.(6) 3AAA 3AAA 4AAA+1 4AAA+1 4AA+1 Plug-in Cards No Yes(7) No No Yes (Plus) Infrared Transmit. Yes Yes(8) No No No Wire Transmit. Yes Yes Yes Yes Yes Cal-to-PC trans(9) Yes Yes Yes Yes Yes Overhead display Yes Yes(10) Yes Yes Yes CBL support(11) No No* Yes Yes Yes QWERTY keys(12) No No* No No Yes Screen capture Yes Yes via link via link via link Screen Resolution 131x64 131x64 96x62 128x64 240x128 Character Display 22x8 22x8 16x8 21x8 ????? Miscellaneous Functions: Calculator HP38 HP48(2) TI-82(3) TI-85 TI-92 Simple Eq. Solver Yes Yes No Yes Yes Simult. Eq. Solver ????? Yes No Yes Yes Poly. Root Finder No limit No limit No 30th order Yes # of matrices 10 No limit 5 No limit No limit max matrix size(12) No limit 125x125 15x15 30x30 99x999 Graphing Functions: Calculator HP38 HP48(2) TI-82(3) TI-85 TI-92 Simultaneous Graph Up to 10 No limit Up to 10 Up to 99 Up to 99 Zoom features 14 15 13 15 ????? Graph Tracing Yes Yes Yes Yes Yes Fnc. Value Tables Yes No Yes No Yes Parametric Graphs Yes Yes Yes Yes Yes Polar Graphs Yes Yes Yes Yes Yes Recur. Seq. Graphs Yes Yes Yes Yes Yes Diff. Graphs No Yes No No No Conic Graphs No Yes No No No 3-D graphs No 7 types No No Yes Area under Curve No Yes Yes Yes Yes Extremum Yes Yes Yes Yes Yes Roots Yes Yes Yes Yes Yes Slopes Yes Yes Yes Yes Yes Tangent Lines No Yes No No ??? Statistical Functions: Calculator HP38 HP48(2) TI-82(3) TI-85 TI-92 Scatter Graphs Yes Yes Yes Yes Yes X-Y line Graphs No No No No Yes Box-Whisker Plots Yes No Yes No Yes Histogram Plots Yes Yes Yes Yes Yes Regression Graphs No Yes Yes Yes Yes Bar Graphs Yes Yes Yes Yes Yes Truth Graphs Yes Yes No No No Notes: 1. In the specifications, "no limit" usually means that it is limited by memory only. 2. There are five different HP48 calculators. There are the HP48S, HP48SX, HP48G, HP48G+, and HP48GX. The S and SX models are older models, and no one would be getting them anymore since the G, G+ and then GX offer all the same features, but with additional enhancements to make the features easier to use. The G, G+, and GX are also 40% faster than the S and SX models. The difference between the G and the GX is that the G has 32K of RAM, and no expandability, while the GX has 128K of RAM and the ability to have two additional plug in cards. The G+ is in between, having 128K of RAM but no expandability. 3. There is a new version of the TI-82, called the TI-83 which should be available soon. It offers all the features of the TI-82, except it has additional statistics and financial functions, as well as displaying a table and a graph side by side. Please note that this feature is not available on the HP48, but is available on the HP38. Also, the TI-83 has an equation solver like the HPs. 4. Cost for HP calculators does not include cables because they can transfer data via infrared. The price for TI's include the cables for linking one TI to another. Also, the HP48G's list price is $135.00, while the HP48GX's list price is $265.00. 5. The available memory listed for the HPs are slightly lower than the given values. The available memory for the HP48G is only 32 K. The HP48GX has 128K of available RAM, and is expandable to 4.5 megs! 6. The batteries used by these calculators are AAA batteries. Rechargeable batteries are not recommended because they have a much lower life span than alkaline batteries. The TI's require an additional CR1616 battery to retain their memory power. The HP's do not need this additional battery, but once you take out the AAA batteries, you have about 3 minutes to replace them with new ones before it loses its memory. The RAM cards for the HP48GX requires an CR1616 battery, however, if you plan to store it outside of the HP. 7. Only the HP48GX support plug-in cards. The HP48G doesn't. 8. If you are thinking of getting the HP's to cheat on tests because of the infrared capability, forget about it. The infrared receivers on the HP's only have a maximum range of THREE inches (The HP's transmitter has a longer range, up to several feet, but that will not help at all unless you are using it as a remote control to watch TV, or you are sending to an infrared device connected to an AC power source, such as the HP LaserJet 5 printers). 9. The Calculator to PC (or MAC) requires additional cable and software. For the HP, you only need to get the cable, which can be made from standard computer parts (a DB-9 and CD cable totaling about $15). No additional software is needed because you can use any communications program of your choice. For the TI, you can either need to purchase a proprietary software and cable for about $60 to $80 at stores or you can download the software free at TI's web site, and try to make your own cable. The same type of package is available from HP, but offers programming tools and debuggers, and costs about the same price. 10. The overhead display unit for overhead projectors is available only for the HP48GX because the HP48G does not have the available extension slot to install the necessary interface card. 11. The CBL stands for Computer Based Laboratory. It is created by TI, so it is not available on the HP of course. It simply allows you to collect data from different sources (sounds, temperature) at set intervals and can be analyzed on the calculator. The CBL unit's list price is approximately $225. Please note that there is a similar device for the HP-48, called the ADCM-48 which is a A-to-D converter and I/O interface that can read from four analog and four digital inputs. 12. Please note that calculators with QWERTY keys are not allowed on the SAT exams. The HP calculators do not have QWERTY type keyboards, but you can connect it to your computer and have the keys from your computer echo on to the HP calculator after installing a simple freeware program such as those found in <http://www.engr.uvic.ca/~aschoorl/archive/as-comm.zip>. 13. The maximum matrix size on the HP48G is only 42x42. The maximum matrix size on the HP48GX is 85x85, but it can be expanded to 125x125 with the addition of an extra RAM card. 14. The TI-92 manual states lists can be up to 999 elements, and data can be arranged in 99 columns of 999 elements each. From: Bernard Parisse o Overhead display: there are special models of the TI92 to do this, standard models give bad results o Memory: The TI92-II model has 198K memory (price in France 1890 FF instead of 1390 FF) o Processor: Modified 68010 at 10MHz o Cabri-Geometre is very slow on the TI, the teachers I met at my lecture told me that they never use Cabri on the TI. o Numeric computations: The HP clearly beats the TI, especially in linear algebra (factorization of matrices, eigenvalues/eigenvectors, etc...) o Symbolic computations: The TI clearly beats the HP... without addition of any math programs. Hence I compared the TI adding the best programs available on the net (i.e. ntheory (10K) for number theory, odeproj for ordinary differential equations (40K), that was all since I had only a 70K TI92) with my HP loaded with Alg48 and Erable. The main advantage of the TI92 is speed (about 5-10 times faster than Erable, 1-2 times faster than Alg48). The main drawback on the HP48 side is the lack of a limit instruction. Some features of Alg48 and Erable are not provided by the TI92: o Factorization of integers (limited to factors less than or equal to 65520 on the TI92, integers may not have more than 614 digits on the TI92) and of polynomials (e.g. the expanded form of: (x^4+x^3+1)*(x^4+x+1) is not factored on the TI92). o Integration: the Risch algorithm is not implemented in the TI, e.g. it can not find the antiderivative of (1+2x^2)*exp(x^2) o Taylor series: This feature is probably implemented like in the HP48 ROM, hence the TI can not solve series(sin(x)/(exp(x)-1)) at x=0 for order greater than 4. o Eigenvalues/Eigenvectors/Jordanisation of matrices o Systems of polynomials equations (Groebner bases) o Ordinary differential equations are only solved with programs like odeproj, no support for Laplace or inverse Laplace transform o A lot of internal programs are not accessible to the end-user on the TI92, as the source code of Alg48 and Erable is freely available. o Programming: Assembler is now available on the TI, but there is no counterpart to SysRPL and the build-in language is comparable to a shell-script langage (with some limitations e.g. for usage of programs in functions) 2.16. What is the Universal Font Library (UFL)? The Universal Font Library, or UFL for short, is a set of libraries designed to help reduce the overhead of replacement fonts between a number of major HP48 programs. The basic idea is instead of each program containing its own replacement font(s), the fonts are stored in a cetral library to save room. In addition, the UFL comes with a Font Maintenance Library (FMnt). If you use some of the programs in the Best Programs List, you may find you need a particular UFL library installed in order to use the program. The UFL is maintained by Andre Schoorl and is distributed under the GNU General Public License. For more information and to obtain the UFL package, see <http://www.engr.uvic.ca/~aschoorl/ufl/>. 2.17. What are the best alternate editors? If you like a smaller font, I would recommend TED by Mika Heiskanen, or MiniWriter by Jean-Yves Avenard. Both use FNT1 from the Universal Font Library (UFL) to allow font customization and to save space. MiniWriter is very small and fast, and has cut, copy, paste, and search features. It is available at http://www.epita.fr/~avenar_j/ TED has slightly more features, such as a character map, but as a result is larger. TED is based on ED, which is the editor that comes with the Jazz library. The latest version is available at <http://www.engr.uvic.ca/~aschoorl/>. If you prefer the medium font, I would recommend HP-Writer by Paquot Christophe. It's quite small, fast, and uses FNT2 from the UFL. Its features include cut, copy, and paste, as well as a macro key and built in User RPL key support. However, it only works on G/GX. The current version is available at <http://www.geocities.com/SiliconValley/Lab/1930/>. Other editors include StringWriter, also by Jean-Yves Avenard, which is a very complete and full featured library. EDEN, by HPFox, is another popular editor in France. Another is QED, which was originally written by Lutz Vieweg but is now maintained by Rick Grevelle. 2.18. Are there any PC fonts for the HP48? Yes, there are several fonts on the Goodies Disks (see the Appendix), as well as some TrueType fonts available at <http://www.hpcalc.org/pc/misc/> 2.19. Is the HP48 serial number available in memory? No. There is no electronic version of the HP48 serial number. This was apparently considered by the design team, but it was determined that the costs would greatly outweigh the benefits. 2.20. What is the format of the HP48 serial number? The HP48 serial number is printed on the back of the HP48, just above the battery compartment. There are two different serial number formats. The older format was used when the HP48 was first introduced and continued through the first part of 1997. The newer format has been used on HP palmtops since about 1993 and was started on the HP calculators in the first part of 1997. The new serial numbers are in this format: ccywwnnnnn cc Place of manufacture (new two-letter code) The known codes are: o SG = Singapore o ID = Indonesia o MY = Malaysia y Year of manufacture. This represents the last digit of the year. A 7 would mean 1997. ww Week of manufacture (01-53). nnnnn The unit number for that week. (first unit on Monday is 00001) For example, if your serial number were SG72706543, the unit was the 6543rd unit manufactured in Singapore during the 27th week of 1997. The old serial numbers are in this format: yywwMnnnnn yy The year the unit was made (add 1960 to this value) ww Week of manufacture (01-53). M The manufacturing location (A for America, S for Singapore) nnnnn The unit number for that week. (first unit on Monday is 00001) For example, if your serial number were 3321S07509, the unit was the 7,509th unit manufactured in Singapore during the 21st week of 1993. 3. Questions about ROM versions 3.1. What does the SX/GX have that the S/G doesn't? SX: The HP48 S is the same as the HP48 SX except that the HP48 S does not have the two expansion slots of the HP48 SX. This means that the HP48 S cannot be expanded and can only access 32K of memory, versus 288K for the HP48 SX (two 128K RAM cards). (Actually, there are third-party RAM cards that contain 256K or 512K on a single card -- this memory is accessed via a bank- switching mechanism.) GX: The HP48 G is the same as the GX except for two differences. The GX has the 2 expansion ports, and also has 128K RAM built in, whereas the G only has 32K. If you plan on heavily using your calculator, you will probably find that 32K is not enough memory. In fact, some of the best HP48 Programs will not even fit in this memory! 3.2. What is the difference between the HP48 G/GX and the HP48 S/SX? The HP48 G/GX calculators are, basically, slightly faster (by 40%) versions of the HP48 S and HP48 SX calculators, with more features, such as 3D-plotting and a new forms-based interface. Much of the HP Solve Equation Library card is now built-in. See Appendix B-1 for a detailed list of GX features. Note, however, that the HP48 G/GX is different from the HP48 S/SX in a number of significant areas: 1. The HP48 GX comes with 128KB RAM, as opposed to 32KB RAM in the HP48 SX. The HP48 G still has 32KB RAM, however. The HP48 G/GX also has twice the ROM (512K), compared the HP48 S/SX (256K). 2. Much of the HP48 G/GX internals have changed, compared with the HP48 S/SX. Unfortunately, this means that many programs written in assembly language or System RPL won't work on the HP48 G/GX. This is especially true of any program that tried to access the display memory directly. 3. The HP48 G/GX CPU runs at 4 MHz, instead of the 2 MHz used with the HP48 S/SX CPUs. However, due to various overheads (memory bank switching, etc.), the speed increase between the S/SX and G/GX is less than 2 times. G/GX throughput is approximately 40% faster. 4. Slot 2 of the HP48 GX can access up to 32 ports (ports 2-33) by bank switching. Each port is 128KB, for a maximum total of 4 MB in slot 2. 3.3. What is the HP48 G+? The HP48 G+ was announced 30 March 1998. It is essentially a HP48 G with more memory - it has 128K of memory instead of 32K. All G+ machines have revision R ROMs. There is no change to other aspects of the calculator model offerings. Specifically, it looks like HP has added to the HP48 family without withdrawing anything. The G, G+, and GX will all continue to be sold. The press release for the HP48 G+ is at: <http://www.hp.com/pressrel/mar98/30mar98.htm> 3.4. How can I tell what ROM revision I have? GX: Type the command "VERSION". Note that this command is not part of any key or menu, and so you must spell it out. Type #30794h SYSEVAL. It returns a string, "HPHP48-x", where x is your ROM revision. This works for both SX and GX. SX: 1. Turn the calculator on (press ON and then release). 2. Press ON again, and hold it down. 3. While holding down the ON key, press and hold down the "D" key (the fourth white key in the top row). 4. While holding down the "D" key, release the ON key. 5. Release the "D" key. The display should be blank, with the exception of three vertical lines (one down the centre, and one down each of the right and left sides). 6. Press the backspace key (it says DROP and CLR over it). A meaningless string of digits should appear in the top line of the display (mine says "705D9:1B8DA178E5A111B6" -- yours may be different). 7. Press and hold down the EVAL key. It should say something like the following, where the ? is an uppercase letter indicating the ROM version: Version HP48-? Copyright HP 1989 8. Release the EVAL key. Hold down ON and hit "C" (the third white key in the top row. This is a general reset operation that returns the calculator to normal from the diagnostic stuff (which is where ON-D puts you). 3.5. What bugs exist in the various versions of the HP48? Rom: A o DEFINE rounds numbers in user-defined functions if STD is not the current display mode. o KGET on a zero length file from another machine will cause the calculator memory to be cleared. o NXEQ from the Graphics Environment with flag -3 set (SYM off in Modes) can overwrite the current equation with a number. o Displaying the clock in 24-hour format causes the one-digits for minutes to be incorrect in the alarm catalog. Roms: A-C o INV returns an incorrect result if used on an 8x8 or larger matrix. To get around this problem, divide the identity matrix with the matrix to invert. Roms: A-D o Entering a symbolic complex number in polar form like (A,<B) (where < is really the funny little angle symbol), gives an expression in A and B that is wrong (the A and B are interchanged so A is the angle and B is the magnitude). o If the clock is displayed during an ARCHIVE via RS-232, there is a chance (not 100%) that calculator memory will be cleared, after the transfer. The work-around is to turn the clock display off before doing the transfer. Should your memory be cleared, you will have to restore the contents of memory from the archive. o TRNC and RND allow for an array in level 2 and a symbolic in level 1 of the stack. This allows you to put an array in a symbolic. Example: [ 2 3 ] '7/8' RND returns Roms: A-E o There's a bug in the EquationWriter that is "fixed" in the Rev J ROM. See Appendix C-1 for details. Roms: E, J o BESTFIT: Occurs when a two dimensional array is stored in \GSDAT (SigmaDAT). Pressing the BESTFIT softkey multiple times will leave a lot of useless reals on the stack. Rom: K o First HP48 G/GX released; includes various bugs affecting ports. Therefore, the version K ROM was only used in HP48 G units. Roms: K, L, M, P o XROOT Function fails when used with list processing unless X=Y. It does not corrupt memory. FIX: Preceed any XROOT which will use list processing with a SWAP Rom: L o Second HP48 G/GX released; fixed the port bugs. This ROM version is that present in the 2,000 HP48 GXs sold at the ASEE conference for $90 apiece. Roms: L, M o HP48 GX may lose all of user memory when: clock is displayed, a library object is be stored in user memory, and a RAM card is lugged in to port one and merged with User Memory. If all four of these conditions are present and the calculator is turned on when the clock is being updated by the system, a loss of all User Memory may occur. FIX: Just type the following in on your calculator: << RCLF -> f << -40 CF OFF f STOF >> >> 91.3 ASN Then turn on USER mode o EquationWriter/Character Picker Bug: If the size of the equation is greater than the regular size of the screen, calling the Character Picker in Equation Writer will garble the screen. o If you store an object into a port > 1 while there is a card installed in slot 1, the end-of-obj-sequence marker (00000) is written to port 1 instead to the destination port. This will cause the 'Invalid Card Data' warning to pop up each power on after a while and, in addition, the memory of port 1 gets currupted (if it's writeable). A temporary fix is to remove the card from slot 1 when changing the contents of the card in slot 2. However a better fix is to get the STOFIX library (available on GD#10 or at HPCVBBS, ~1K in size). o Tail Bug: The TAIL command returns an error on single length strings. This was fixed to return an empty string in later Roms. Examples: "X" TAIL --> Error: Invalid Dimension (Rom M) "X" TAIL --> "" (Rom R) Rom: M o Evaluating a tagged object which contains an operator (+, -, *, /, etc) as the second or subsequent character will leave an External and System Binary on the stack, as well as the original object. Roms: L, M, P o SigmaDAT: Put a NON-MATRIX in \GSDAT (SigmaDAT), run STAT graphical apps, edit \GSDAT. Causes a crash. o XRECV will fail or cause memory lost if the amount of free RAM left is not about twice the size of the expected file. FIX: See FXRECV on GD 9. Note that FXRECV is not necessary for Rom R, and in fact will not even run properly on Rom R. o RREF does not transform the matrix into Row Reduced Echelon Form correctly if the first column of the matrix consists entirely of zeros. It may also return incorrect answers in some matrices. A work-around for this bug is to delete any leading all-zero column(s) from the matrix; this may be done using the Matrix Writer, via its -COL menu key, or via commands: 1 COL- DROP (to drop the first column). Since row-reduction operations never change any all-zero column, you already know in advance that the given column(s) must be all-zero in the final result. Roms: L, M, P, R o portnum: { dir ... var } RCL/EVAL fails if portnum >= 2 o Rotation rate to angular frequency conversion bug. See Appendix C-2 for a complete write-up. Roms: M, P, R o Repeated executions of FFT or IFFT can cause a memory loss. The FFT and IFFT warmstart problem is caused by a CPU return stack overflow during interrupt handling. The problem can only occur when the argument to FFT or IFFT is an MxN matrix with both M > 1 and N > 1. The vector argument case is immune to this problem. FIX: To compute the FFT of a matrix without risking warmstart, expand the matrix into its row vectors using ->ROW, compute the FFT of each row vector, collect the results into a matrix using ROW->, expand the matrix into its column vectors using ->COL, compute the FFT of each column vector, and finally collect the results into a matrix using COL->. Except for less precision, this is the same result as would be obtained by applying FFT on the original matrix. Use the same procedure with FFT replaced by IFFT to compute the IFFT of a matrix. Here are program examples implementing the "Matrix FFT" and "Matrix IFFT": MFFT << ->ROW FFTLP ROW-> ->COL FFTLP COL-> >> MIFFT << ->ROW IFFTLP ROW-> ->COL IFFTLP COL-> >> FFTLP << -> n << 1 n START n ROLL FFT NEXT n >> >> IFFTLP << -> n << 1 n START n ROLL IFFT NEXT n >> >> o Equation Writer/Equation Library interaction bug: If you pick an equation from the EQ library, enter solver for that equation, enter an algebraic on the stack like 'X^2', and press the down arrow key to view algebraic in EquationWriter, the name of the equation will appear in the EquationWriter along with the unassociated algebraic. Roms: M, P o BESTFIT: Occurs when a two dimensional array is stored in \GSDAT (SigmaDAT). Pressing the BESTFIT softkey multiple times quickly can cause a warmstart, or SigmaDAT to be erased. This occurs sometimes just by pressing BESTFIT repeatedly, regardless of \GSDAT content. This bug can also be triggered by pressing the BESTFIT softkey quickly after pressing any other key. Simply pressing MODL then BESTKEY quickly will trigger the bug. Rom: P o PROOT: If you put a matrix of coefficients on the stack and press PROOT repeatedly, you will get a warmstart. Roms: A-R o MatrixWriter Bug: This shows up when deactivating and reactivating any of the two direction movement fields. If you do this, the active matrix field won't move as it's supposed to. For example: Launch the matrix writer (check that your GOFORWARD field is activated). Type [1] [ENTER]. The active matrix field moves forward as it should. Deactivate the GOFORWARD field and activate it again. Now enter [2] [ENTER] [3] [ENTER]. The digits should show up on the same row, but they don't, because after you deactivated and reactivated the GOFORWARD field, the active matrix field stops moving according to the movement fields. o DTAG Bug: When the DTAG command is executed without any arguments on the stack, the error message "XLIB 0 0 Error" is given, which is non-standard. Roms: K-R o Equation Library Solver and Multiple Equation Solver Bug: Pressing MSOLVR or MUSER after setting user flag 63 can cause Memory Clear. Example: CLEAR, 63 CF, EQNLIB, down-arrow, ENTER, down-arrow, [SOLV], NXT, 63 SF, right-shift MUSER, DROP --> Memory Clear. This bug is also found in the HP Solve Equation Library Card (HP 82211B, but not 82211A) for the SX. 3.6. What is new with the revision "J" ROM? (S/SX) The revision J ROM has a faster equation writer, as well as some bug fixes. Scrolling of graphics is also faster. One "problem" is that the revision J ROM changed some undocumented ROM entry points, which broke those programs that used them. If you have a Rev J ROM, you will not be able to run some old programs. 3.7. What happened to ROM revisions G, H, I, O, and Q? These versions either were never released to the public, or were skipped over. I have received confirmation of the existence of a HP48 S with ROM revision F. So it appears revision F was in fact released to the public, although very few must have made before revision J came out. 3.8. Can I upgrade my HP48 S/SX? When the G/GX first came out, HP had a trade in program. This is no longer in operation. The only option remaining is to try to sell your S/SX privately. 3.9. Can I upgrade my buggy GX to the latest ROM revision? As far as I know, not any more. They had a program a in early '94, but it is over now. Contact the following for more info: Hewlett-Packard Corporation Calculator Support 1000 NE Circle Blvd Corvallis, OR 97330 Phone: (970)-392-1001 3.10. What's the latest ROM version? o Revision R is the latest ROM version of the G/GX series. o Revision J is the last ROM version of the S/SX series. 3.11. Why would I buy a S/SX rather than a G/GX? Here's the top reasons to buy a S/SX instead of a G/GX (Thanks to all who contributed): 1. May be slightly cheaper, having only 32K RAM. 2. It isn't THAT outdated. 3. So what if it's a little slower? 4. You didn't need all those useless equations, graphics capabilities, and math and science functions anyways! 5. If you break it, you're out of less money! 6. You like seeing how much you can fit into 32K RAM. 7. You like slow file transfers, using Kermit instead of X-Modem. 8. You want to be able to use all those lists of SYSEVALs for the SX. 9. You like having only 3 ports available max. 33 is ridiculous! 10. Since it doesn't have a built in equations library it is less likely to be banned on tests. 11. Only wimps need GUI's, dialog boxes, and choose lists. 4. Questions about the Operating System and Using the HP 4.1. How do I find the checksum of an object? Many documents (including this FAQ) make references to the "checksum" of an object. This is a 16-bit user binary resulting from a CRC calculation on the contents of an object. This binary is supposed to be relatively unique, with only 1 change in 65536 of accidental equal checksums on two different objects. This allows you to distinguish programs that look the same but may be quite different (even if the size of them is the same). It is also often used to verify correct transmission of files. You can find the checksum of an object using the BYTES command. This will return you two things - the size of the object in bytes on level 1, and the checksum on level two. Note that while the checksum of a variable name is the same as running the checksum on the object itself, the sizes will be differ by 4.5 bytes + the size of the variable name itself. In rare cases the checksum of two objects can be the same, even if the objects are different. This is due to the limited nature of the HP48's checksum function. You can use the SAME command in these cases. 4.2. I typed RULES on my G/GX and got a crossword puzzle! From: Joe Horn Many commercial programs (like Windows) have similar hidden screens that list the program's design team. Since they are always so cute and well hidden, they are often referred to as "Easter eggs". The RULES command on the G/GX is one such example. Try using the RULES command. The names you see are as follows: /----------------------\ | M G | | P DIANA | | CHARLIE X B D | | BILL U N TED A | | O A L N ALCUIN | | B I JIM V | | RON S E | \----------------------/ ALCUIN was the HP-internal code name of the HP48 G during development, because Alcuin was Charlemagne's teacher, and Charlemagne, as you remember, was the code name of the HP48 SX. The other names in the "Easter egg" above belong to: o BILL Wickes (list processing; "Father of RPL") o CHARLIE Patton (RPL operating system) o TED Beers (parameterized outer loop; interactive stack; key handling system; high-level display management; input forms) o DIANA Byrne (project manager; plotting; graphics) o GABE Eisenstein (EquationWriter) o BOB Worsley (I/O) o PAUL McClellan (unit management; math) o CLAIN Anderson (product manager; marketing) o DENNIS York (manager) o JIM Donnelly (EQ LIB; list processing; variable tic logic; developer support) o MAX Jones (menu system; editing) o DAVE Arnett (hardware) o DAN Coffin (manuals) o RON Brooks (marketing) 4.3. Why does my HP48 occasionally "freeze" for a moment? The HP48 must occasionally do "garbage collection" to free up unused memory, and it is this garbage collection that is causing the momentary "freeze". "Garbage collection" is where the HP48 scans through memory, looking for objects that are no longer used. Using less stack supposedly makes garbage collection go faster. The easiest way to force a garbage collection is to run MEM DROP. Otherwise you can use #05F42h SYSEVAL or the SysRPL command GARBAGE. 4.4. What do I do if my HP48 locks up? o NOTE: If you have it, read the sections in the GX manual starting on page 5-16, "Special Memory Operations", and "Testing Calculator Operation" on page A-9. o NOTE: under most circumstances, your calculator should never lock up. Some earlier versions of the G/GX do this due to bugs. Of course, depending on the program being run, it may appear to lock up, but pressing the "ON" key usually interrupts whatever the calculator is doing. If it does lock up, this is usually caused by a buggy assembly-language or system RPL program, and, chances are, the memory contents of your HP48 are gone (as in "destroyed", "terminated", "wiped out", "deleted", etc.). 1. First, check the batteries to make sure that they are installed correctly. 2. Next, try is pressing the "ON" key again and again very RAPIDLY. The operative word here is "rapidly". It's possible to write a program that can only be interrupted during a very narrow window, and so you must press the "OK" key again and again very rapidly to interrupt the program. If the calculator doesn't respond within ten or so seconds, go on to the next step. 3. Press "ON-+" a couple of times, just in case the LCD display intensity was turned down. Here, "ON-+" means: o Press and HOLD DOWN the "ON" key. o Press and release the "+" key, WHILE HOLDING DOWN THE "ON" KEY. o Release the "ON" key. 4. If this doesn't work, the next thing to try is ON-C. This is a "warm-start" or "system halt". Note that this will CLEAR the stack. Here, "ON-C" means: o Press and HOLD DOWN the "ON" key. o Press and release the "C" key, WHILE HOLDING DOWN THE "ON" KEY. o Release the "ON" key. 5. If this still does not work, it is possible that the HP is not responding because it is not accepting input from the keyboard. It is possible to execute a system halt without the keyboard using the hidden reset button. The reset button is hidden under one of the two upper rubber feet on the bottom of the calculator (it's under one of the two feet near the serial connector and I/R port). Note that the location of the reset button (under which foot) varies from calculator to calculator. If you gently pull out the rubber feet, you'll notice that there is a small hole under each foot. The reset button is located in the hole that has an "R" next to it. Once you've located the correct hole, you press the button by GENTLY sticking an unbent paper clip, into the hole with the "R" next to it. Hold for one second and remove. 6. The next thing to try is a complete memory reset. Depending on the state of your calculator, this may or may not preserve the contents of memory. At the very least, even if the contents are preserved, the contents of the HOME directory will probably be moved into a new directory below HOME (HOME will be empty with the exception of this new directory); you'll have to manually move the items back into HOME. To perform a complete memory reset, press ON-A-F. This means: o Press and HOLD DOWN the "ON" key. o Press and HOLD DOWN THE "A" key, WHILE HOLDING DOWN THE "ON" KEY. o Press and HOLD DOWN THE "F" key, WHILE HOLDING DOWN THE "ON" AND "A" KEYS. o Release all of the keys. o At this point, the calculator will ask you if you want to recover memory. Answer "yes" to this question. Note that this can take a long time. If you answer "no", all of memory will be cleared (the old contents will be lost). 7. If that fails, you should still be able to induce a complete memory reset by removing your batteries and pressing ON several dozen times. This will drain the capacitor that stores information when the batteries are removed, and you should get a "Try to Recover Memory?" prompt if you have pressed ON enough times to reset your calculator. If this doesn't work you can try taking the batteries out for a few hours and then putting them back again. You should definitely try this method before even considering the next step! 8. WARNING: the next method is HIGHLY unrecommended! Permanent damage to your HP can result if you try this. In particular, you could fry a couple diodes used to protect your HP48. You have been warned! If your HP48 does not respond to any of the above attempts, you might consider reversing the polarity of 2 of the 3 batteries VERY BRIEFLY, pressing ON, then correcting the batteries. Your HP48 should start with a "Try to Recover Memory?" prompt. Even reversing only 2 of the 3 batteries is dangerous, but it is safer than reversing all 3 batteries. Note that simply shorting the battery terminals will not discharge the storage capacitors. There are diodes between the battery terminal and the storage capacitors which prevent the DC current from flowing backward. This method apparently drains the capacitors and reverse charges them by running current through the parasitic input protection diodes in the various CMOS chips. 9. If all of the above fail, or if you decide not to try the last step, you may have to contact Hewlett Packard for service. 4.5. My HP48 seems to take longer to turn on and off. The usual causes for this are RAM/ROM cards and libraries. When you turn the calculator on, it checks RAM (the more you have, the longer it takes), and checks to see if any libraries need initializing. Also, having a lot of alarms can supposedly also cause this. 4.6. What are all the different ON-KEY combinations? From: Dave Arnett ON In most cases, this will move you to, or toward, the stack environment. ON+A+F This is the manual Coldstart. It will break out of almost any hung program, and offer you the dreaded option... "Try to recover memory?" Note that this is your next-to-last resort in a lock-up, so don't give your machine this three-fingered salute unless you really want to possibly clear memory. ON+B This is the Oops! key for ON codes. For many ON sequences, this cancels the operation, so long as you press the B before releasing the ON key. Try it sometime, if you must, just so you remember it. It can be a life-saver, in case of an accidental ON+A+F in process, or even accidentally hitting ON during a plotting routine. ON+C This will initiate a Warmstart. You'll lose the stack and PICT, but it will often get you out of a locked up program with memory intact. ON+D Enters interactive test mode. Back up your own machine and play around. Exit this test mode with Warmstart, ON+C. See the next question for all the various tests available here. ON+E Starts a looping self-test mode. Kinda dull after the first five minutes, but it keeps a rather solid tempo. Exit with Warmstart, ON+C. ON+4 Cancels repeating alarms. ON+1 Screen dump utility. ON+'+' and ON+'-' Adjusts display contrast. ON+SPC Initiates Coma Mode and clears Warm Start Log. In Coma mode, all the clocked activity is halted. The battery power drain is basically the few nano-amps [nA] necessary to sustain your RAM contents. The Warm Start Log is a nearly bullet-proof area of memory which keeps track of the last four hazardous events. View it using the command WSLOG. This log is one of the few things not cleared by a Coldstart. But it is cleared by ON+SPC. Enter Coma this way if you want to clear the Warm Start Log, if you are planning to study crystal healing in Tibet for a few years and want to keep your pirated version of Tetris alive, or you just have a low power fetish. Exit Coma mode with the ON key (tough to remember, huh?), and plan to find your stack cleared out. Two additional notes on this Coma stuff. First, I'm not gonna try to list the log codes in WSLOG. Sorry! Second, if your machine is on, and you drop the batteries out, you will usually end up in a coma mode to preserve power. WSLOG will not be cleared. Instead, you will find a code 1 entry there. Some people are paranoid and want to be in Coma when they change batteries, just in case they have a sudden emergency call from the Prime Minister and don't get back to their battery change for a half hour. If you are one of these... shall I say, weenies? No, that would be unprofessional ...users, then I recommend you use the ON+SPC entry route, rather than the kamikaze method of dropping batteries with the machine running. Myself, I just turn the machine OFF, like the manual says. Now, a Coma story... sort of. During the G/GX development, I maintained a small number of units on which I changed ROM chips as incremental code releases came out. This was so folks like Bill Wickes and Jim Donnelly could have fully-real hardware to test, instead of just the EPROM handsets some of you may have seen. We always backed up anything of importance in the machine before we did this. But I got into the habit of using ON+SPC before I opened up the calculator. Better than half of the time, I could remove the batteries, open the case, desolder the old surface-mounted ROM chip, solder down a new chip, and reassemble the machine... with all of RAM intact! When I pressed ON, I'd come right back up without a "Try to Recover Memory?" prompt. Pretty good, huh? The folks who put that mode into the machine certainly weren't in a coma. 4.7. What are the different interactive self-tests? Pressing ON-D enters the interactive self test function of the HP48. When you first press ON-D, your HP will beep and you will see 3 vertical lines, one on each side of the screen and one in the middle. You can exit this mode with a Warmstart, ON-C. The tests are: [A] Displays CPU speed [B] LCD test. Press Enter to cycle through the tests [C] Internal ROM test [D] Internal RAM test [E] Keyboard test. Starting with [A], press all the keys in order, left to right, top to bottom. If all goes well, the HP will show "KBD1 OK". [F] Partial keyboard test [G] ESD test monitor. Battery status is shown by bars. [H] UART loop-back test [I] Wired UART echo [J] Shows what cards are plugged in. Press any key a few times. [K] Test RAM cards in ports [L] Blanks display [M] Sends system time from IR port [N] Receives system time from IR port (have another HP send it) [O] IR loop-back test [P] IR UART echo [S] Shows test start time [T] Shows test fail time [U V W X Y Z] Looping test [ENTER] Initialize test times [DEL] Test summary [BACKSPACE] Enters memory scanner (SX only) When the HP48 is in test mode (ON-D or ON-E), the test results that are displayed on the screen are also sent to the serial port at 9600 baud, 8 bits, no parity, 1 stop bit. This seems to be unaffected by any settings in IOPAR, PRTPAR, or the system flags. I can only guess that this feature was included for factory testing purposes. This does explain, however, why the I/O annunciator lights up so much during the self test. 4.8. Why do I get an ESD error when I check my batteries with the self test? From: Detlef Mueller If your HP48 batteries are low, try this test with fresh alkaline AAAs. This test first records the CRC of a RAM segment, then starts a loop where it creates power peaks and recalculates the CRC again until you press a key or the CRCs differ. In the latter case one or more cells of your RAM were "Electro-Statically Discharged" and the test exits with the last CRC done. If there's a hardwaer problem, this number should differ in consecutive executed ESD tests - with fresh AAA alkalines! Old ones or non alkaline batteries may cause trouble under this test condition. If the test runs continuously, the bars on the screen reflect the battery status (low bat if bar is there) of port 2 (below the 2), port 1 (below the 1), and the main AAAs (below 0). If the AAAs are very low, the V bar comes up. 4.9. I can't account for some of the RAM in the HP48! The HP48 S/SX/G have 32K base memory, and the GX has 128K. However not all this memory is available to the user. The operating systems uses memory for system variables, flags, fonts, last stacks, last arguments, last menus, and such. It also can be any one of a number of things: 1. Enabling the use of LAST STACK, LAST ARG, LAST CMD, etc., uses up extra RAM, as the calculator has to keep track of the last stack, arguments, command, etc.. This is particularly important with LAST STACK if you have a large/complex stack, as the HP48 has to keep enough information around to recreate the stack after each operation. You can clear out these variables by pressing ON-C (but also note that this will clear out the stack, the graphics PICT, etc.) 2. From William Wickes, a member of the HP48 development team: Here's a candidate for "most obscure way to use up memory on the HP48 SX." When a program executes DOERR with a string argument, the string and hence the program too if the string is embedded in the program are referenced for the sake of the ERRM command. Thus if you purge the program, the memory used by the program is not reclaimed until the ERRM reference is updated to a new string. If the string is in a port, you will get the Object In Use error if you try to purge the library or backup object containing the string. A system halt prior to a PURGE will not help unless the object is in port 1 or port 2 (it will reclaim memory held by a successfully purged but still referenced object). For port 0 objects, the only way to break the reference is to execute DOERR again with a new string. 3. Occasionally, I have had problems with libraries disappearing, but still taking up memory. I found that an "ON-A-F" reset will cause these libraries to re-appear. If you still cannot account for a large chunk of memory, I would suggest a hardware reset, after backing up your memory. 4.10. What are the best methods for installing and removing libraries? To install a Library: 1. Download it into a variable of the calc. 2. Place the library on the stack. 3. Type the number of the port in which you want to store the library in. 0 is appropriate if you do not have any expansion cards. 4. Press STO to store the library in that port. 5. Turn the calculator off and then on, or press ON-C, to finish installation of the library. Sometimes you have to purge the variable containing the library before storing it in a port, if you are low on memory. See the next question for more information. If you have FXRECV installed: Just type a port number, hit FXRECV and the library will automatically go into the specified port. All you have to do then in turn the calc off and then on to complete the installation. To delete a Library: Say you have library 1234 in port 0 that you want to delete. 1. Go to the directory to which the library is attached. In most cases this will be HOME. 2. Enter :0: 1234 3. Press [ENTER] or type DUP 4. Type DETACH 5. Type PURGE If this doesn't work, there may be a reference to the library still in temporary memory. Try warmstarting with ON-C, then try again. Libraries with very low library numbers may require the addition of a constant in order to delete them. For example, to delete a library 4 in port 0 you can add 2048 to the library number, as follows: 1. Type :0: 2052 DETACH 2. Type :0: 4 PURGE Therefore, here is a fairly general program for detaching and purging most auto-attaching libraries; the only required argument being the real library number (e.g. 218 in the above case): \<< PATH SWAP HOME DUP 2048 + DETACH DTAG "&" \->TAG PURGE EVAL \>> 4.11. How can I attach large libraries? If have just successfully transferred a library to your HP, and try to store it in a port you may get an "Insufficient Memory" error. This is because your HP is trying to make a duplicate copy to store in your port, but it doesn't have any memory to do so. This is especially true on the HP48 S/SX/G since they only have 32K of memory built in. The solution is to push the library onto the stack, then purge the original variable containing the library. At this point, the only copy of the library that exists is on the stack. Now you can store the library in a port as usual. This method avoids temporarily trying to have two identical copies in memory at the same time. For example, say you have a library in 'LIB' and you wish to store it in port 0. You would enter the following: o Go to the directory containing 'LIB' o Recall the library to the stack: 'LIB' RCL o Purge the original from user memory: 'LIB' PURGE o Enter port number to store in: 0 o Press STO For the opposite problem - sending large libraries you can follow the reverse procedure. That is, recall the object from the port to the stack, purge the original in the port, store it in a variable and then send it. Alternatively if the library is in a non-covered port (0/1/2 on SX or 0/1 on GX) you can use the following simple program suggested by Dan Kirkland: \<< -> lib \<< 'lib' SEND \>> \>> This does not require a second copy of the library and avoids all the complications of trying to purge a library and then re-installing it. 4.12. What are those little numbers near the top of my screen? The little numbers are "user flags". When you or a program sets any of the user flags 1 through 5, little numbers corresponding to the set flags are displayed at the top of the screen. The HP uses negative flags for setting various modes and functions, while positive flags were reserved for the use of the user. To set a user flag type the number, then SF. To clear a user flag type the number, then CF. Some programs will use the user flags without you being aware of it. So, if you have a "1" at the top of the screen you can type 1 CF to get rid of it. 4.13. Can I use my HP48 as a remote control? There are numerous programs available for using your HP48's IR port as a remote control. However, the level of support depends on the particular unit you wish to control. The HP48 is capable of reproducing many of the IR controls of many popular brands of appliances. However, some remotes run at speeds that the HP48 is unable to reproduce. Due to their faster processor speed, the G/GX calculators are able to support more remote controls but are still limited in some cases. With typical remote programs you have to "teach" your HP48 by sending it the various IR sequences with the original remote control. There are some advantages to using your HP48 however: o You can impress your friends that you can use your calculator to control your TV! o You can set alarms to turn your things on and off at predetermined times. o You can use it as a universal remote. The best remote program by far is Remote by Bjorn Gahm. It has a large database of existing remotes, meaning you may not have to "teach" your HP48 your specific remote if it is already supported. However it also have the ability to learn new codes. See the best programs list (later in the FAQ) for the specific URL. 4.14. Can the HP48 be used as a DTMF phone dialer? To make phone dialing tones, you need to produce two simultaneous tones. The tones used to dial phones are known as DTMF (dual tone multi frequency) tones, which consist of two tones at the same time. The speaker in the HP48 is not capable of supporting the DTMF tones because it can only make a single tone at a time. The best the HP48 can do is switch very quickly between one frequency and another. Some attempts have been made in machine language to support DTMF, however they have been unsuccessful. Therefore, you cannot use the HP48 as a phone dialer. 4.15. How can I run a program on warmstarts and/or power-up? You can use some of the utilities available on the Goodies Disks (see Appendix E.5 on where to obtain these): o AUTOBOOT (GD #7) warmstarts every power-up o AUTOEXEC (GD #10) Runs 'GO' every power-up o AUTOPORT (GD #7) Runs &:AUTOEXEC every warmstart o AUTOSTRT (GD #7) Runs AUTOEXEC every warmstart Some stack libraries come with support for AUTOEXEC or an equivalent built in (for example, the Java library supports AUTOEXEC). If one of the libraries you have installed supports such a feature, you may not need any of the utilities above. 4.16. I could speed up my HP-28S. How can I speed up my HP48? You can't, really. Unlike the HP-28S, the clock speed in the HP48 SX is hardwired to 2 MHz, and to 4MHz in the HP48 GX. Digitalis <http://www.Digitalis.de/> has a "speed-up" module available. They sell 48G's with this module added (it looks like it adds about 50DM/$30 or so to the cost). I'm not sure what it does, but I think it boosts the clock speed. Apparently it can be turned on and off as needed, at the sacrifice of shorter battery life. However, in some cases, you can speed up the HP48 by turning off the display refresh, which supposedly takes up about 11% of the CPU time. Detlef Mueller submitted a program called SPEED to comp.sources.hp48 that turns off the display refresh. Of course, since it turns the display off, it is only suitable for long non-interactive runs like calculating large integrals, compiling, etc... Look in the various HP48 archives for a copy. 4.17. What is the hidden directory and how do I access it? The "hidden directory" is a subdirectory of the HOME directory. It is created on startup, and it contains variables with your alarms and user key configurations. You can use the hidden directory to store whatever you want, however you CAN NOT ORDER the contents of this directory, as this causes memory loss. The name of the hidden directory is a null character, ''. The only way to get a null character is to use a syseval. You can use the following program to access the hidden directory: << HOME (changes to home dir) #15777h (syseval to get null character) SYSEVAL (returns '' to stack) EVAL >> (changes to hidden dir) To exit the hidden directory, use HOME or UPDIR. This will return you to the HOME directory. Also, by putting the null character as a part of your HOME custom directory, you can switch right into the directory by pressing the softkey. Note: The SysRPL command NULLID returns a null character to the stack; it is the same as doing #15777h SYSEVAL. 4.18. How can I recall one object from a memory archive? From: Joe Horn There is a little-known method of recalling objects from within archives. Just make a list representing the PATH to the object, and tag the list with the port number. Then hit RCL or EVAL. For example, if your archive in port 1 is called BKUP, and it contains a directory called GAMES which contains a program called REVERSI, you can run the game directly (without having a separate copy of REVERSI stored anywhere!) by: :1: { BKUP GAMES REVERSI } EVAL Or, you can RCL instead of EVAL, and it will be pushed onto the stack. o This method only works in ports 0 and 1 in a GX. It works on any port in the SX. o This method works with directory objects stored as backup objects, as well as with the results of the ARCHIVE command, because they are both really the same thing. 4.19. Are there any key combinations that aren't in the manual? From: John Meyers Yes, on the G/GX there are a few keys that aren't mentionned. They are: o [right-shift] [down-arrow] = Review menu keys o [right-shift] [right-arrow] = Kermit server mode [Right-shift] [View] is hidden in Appendix G (Operation Index) of the User's Guide [Edition 4] (which comes with the calc), among the several entries for the word VIEW. AUR [Edition 1] (in chapter 3, Command Reference, under SERVER) gives the alternate keys [right-shift] [cursor right] (but of course AUR doesn't come with the calc). This alternative was left out of Appendix G of the User's Guide. Donnelly's HP48 Handbook [2nd Ed.] even lists it first! 4.20. How do I find out about commands not in the GX manual? From: John Meyers Besides purchasing the Advanced User's Reference Manual (AUR), you can look in Appendix G of the G/GX User's Guide, which briefly summarizes every command available in the G/GX, including all the commands not mentioned anywhere else in the User's Guide. Often even the brief description given in this Appendix is sufficient for you to use the command (and to know it exists!). Some notes on omissions, however: o VERSION and "_" (attach unit) are missing in Edition 4. o SUB works with arrays in the G/GX, but this is not in the HP manuals, nor in Donnelly's HP48 Handbook 2nd Ed 6/93. You can specify any two "corners" of a rectangular sub-matrix (like with GET), and it extracts the sub-matrix. Also works with vectors. 4.21. How can one delete (or purge) an entire directory? o To purge a subdirectory and all that it contains, type in the name in single quotes, then PGDIR. o To purge all variables in the current directory, but not the directory itself, type CLVAR. Note that with CLVAR, if the current directory contains a non-empty subdirectory, an error occurs at that point, and no subsequent variables are purged. 4.22. How does binary wordsize affect my calculations? From: John Meyers Some of the following (but not all) is in the User's Guide, under "Binary Arithmetic and Number Bases" (Chapter 15 of G/GX). The system flags contain a segment which specifies a "binary word size". This word size limits how many low-order bits of a binary value are displayed on the stack, and equally determines how many low- order bits of the arguments and results of binary arithmetic/logical/shift operations are used. Curiously, the binary word size has no effect on entering values into the command line - what you originally enter is displayed in truncated form on the stack, but when you view it again in the command line (which temporarily reverts back to STD numeric display and 64-bit wordsize) you will find the complete value as entered is still intact. As soon as you begin using functions on that value, however, the arguments to binary functions get truncated to the current wordsize before the functions are executed, and then the final result of the function gets truncated again. You can recall the current wordsize using RCWS and set the wordsize using STWS. STWS accepts a real number argument in the range 1-64 (out of range values get adjusted to either 1 or 64), and it also accepts a binary argument, in which case the absolute value of the low-order 20 bits is used (just in case you wondered why #1048576d STWS RCWS gives an answer of 1). Don't try adjusting the binary wordsize in the hope of saving memory by using shorter values; every "user binary integer" (type 10) produced by User RPL occupies 13 bytes, no matter what the current wordsize; the HP48 just sets the leading bits to zero when displaying on the stack or performing calculations. 4.23. Can I add my own equations to HP's Equation Library? No, the Equation Library is in ROM, and can't be written to. There are several programs which allow you to create your own equation library such as EQBrowser, EQ Lib, Equation Manager, and xMGR.LIB. All of these programs can be found at <http://www.hpcalc.org/utils/misc/>. 5. Questions about Math, Plotting, and Equations 5.1. Why does (1/3)*3 equal 0.999999999999? This is due to the way numbers are typically represented by computers and calculators. There are infinitely many numbers, like `1/3' and `pi', that cannot be exactly represented internally (their decimal representations go on forever, and often cannot even be represented as a fraction, as in the example of `pi'). As a result, any calculations that use these numbers are bound to be off. 5.2. Why does my HP say that 0 to the power of 0 equals 1? Some claim that 0^0 is defined as 1, some claim it is indeterminate. The HP mathematicians decided to use the definition. Here is some more concrete info shamelessly lifted from the Sci.Math-FAQ: Question: What is 0^0 ? Answer: According to some Calculus textbooks, 0^0 is an "indeterminate form". When evaluating a limit of the form 0^0, then you need to know that limits of that form are called "indeterminate forms", and that you need to use a special technique such as L'Hopital's rule to evaluate them. Otherwise, 0^0=1 seems to be the most useful choice for 0^0. This convention allows us to extend definitions in different areas of mathematics that otherwise would require treating 0 as a special case. Notice that 0^0 is a discontinuity of the function x^y. Rotando & Korn show that if f and g are real functions that vanish at the origin and are analytic at 0 (infinitely differentiable is not sufficient), then f(x)^g(x) approaches 1 as x approaches 0 from the right. From Concrete Mathematics p.162 (R. Graham, D. Knuth, O. Patashnik): "Some textbooks leave the quantity 0^0 undefined, because the functions x^0 and 0^x have different limiting values when x decreases to 0. But this is a mistake. We must define: x^0 = 1 for all x, If the binomial theorem is to be valid when x=0, y=0, and/or x=-y. The theorem is too important to be arbitrarily restricted! By contrast, the function 0^x is quite unimportant." Published by Addison-Wesley, 2nd printing Dec, 1988. References: H. E. Vaughan, The expression '0^0', Mathematics Teacher 63 (1970), pp.111-112. Louis M. Rotando & Henry Korn, "The Indeterminate Form 0^0", Mathematics Magazine, Vol. 50, No. 1 (January 1977), pp. 41-42. L.J. Paige, A note on indeterminate forms, American Mathematical Monthly, 61 (1954), 189-190; reprinted in the Mathematical Association of America's 1969 volume, Selected Papers on Calculus, pp. 210-211. 5.3. What is RPN? Jan Lukasiewicz wrote a book on formal logic in 1951 that showed that mathematical expressions could be specified without parentheses by placing the operators before (Polish Notation) or after (Reverse Polish Notation) the operands. For example, the expression: (4 + 5) * 6 Could be expressed in RPN as: 4 5 + 6 * 6 4 5 + * Polish Notation is also known as prefix notation and Reverse Polish Notation (RPN) is also known as postfix notation. 5.4. Why did HP use RPN in their calculators? From: Dave Hicks <dgh@hpmuseum.org> In the years that followed Lukasiewicz's book, computer scientists realized that RPN or postfix notation was very efficient for computer math. As a postfix expression is scanned from left to right, operands are simply placed into a last-in, first-out (LIFO) stack and operators may be immediately applied to the operands at the bottom of the stack. By contrast, expressions with parentheses and precedence (infix notation) require that operators be delayed until some later point. Thus, the compilers on on almost all modern computers converted statements to RPN for execution. (In fact, some computer manufacturers designed their computers around postfix notation.) At the time that the HP-35 was introduced, other pocket calculators typically used a partial algebraic model. That meant they could evaluate trivial expressions like 4+5 but couldn't handle anything that involved parentheses or algebraic precedence. The technology of the time didn't allow for full algebraic compilers in pocket calculators. RPN allowed HP to produce a pocket calculator that could evaluate arbitrary expressions using the available technology. For many, learning a new style of entry was a small price to pay to be able to evaluate arbitrary expressions on a calculator. Once the technology to produce algebraic compilers could fit into a pocket calculator, most RPN users had decided that RPN was more efficient and consistent for the user as well as for the calculator. Also, because subexpressions are evaluated as they are entered, entry errors are more obvious with RPN. Another advantage to RPN is consistency between machines. Early algebraic models had differing limits of the complexity of the expressions they could evaluate. For example, TI catalogs from the late 70's listed how many levels of parentheses and pending operations each model could handle. Even today if you begin to use an algebraic calculator, you need to determine just "how algebraic" it really is. For example, some switch to RPN for unary operators (ie 5 SIN rather than SIN(5)) and some can't directly enter an expression like: 4+5 ----- 6+7 5.5. Is there an alternative to calculating in RPN? Many people just can't get used to the interaction with the stack to do calculations. A simple alternative is to place your equation in tic marks like '8+10*3' and to use the EVAL as an equals key. This way you can enter numbers just as you would write them on paper. 5.6. Why do I get unexpected values when I add temperatures? Example: I add two temperatures like 34 deg.F and 11 deg.F, and I get 504.67 deg.F. Why don't I get 45 deg.F? This occurs with the S/SX only. This behaviour changed in the G/GX. With the G/GX, adding 34 deg.F and 11 deg.F will give 45 deg.F using TINC and TDELTA. However, the G/GX will only add or subtract temperatures if the units are the same; it is now an error if they are not. If the units attached to the number consists only of a temperature and nothing else, operations are done using an absolute temperature scale (relative to absolute zero). If the units consists of a temperature and something else, such as degrees/minute, the operation will not be done using an absolute temperature scale. It also does not make any physical sense to add two temperatures. You can't add a cup of water at 20 degrees C to a cup of water at 30 degrees C and end up with two cups of water at 50 degrees C. 5.7. How can I add my own units? What's the 1_? unit for? Note: Some later editions of the G/GX series manuals have some similar information on this subject. Another feature is the generic unit, 1_?. It seems to be intended as a generic unit, to allow you to make new units not based upon any of the built-in ones. You could use it to create a conversion utility for currencies or bits and bytes. Before you create either, check the FTP sites to see what others have done in this regard. o User units may be defined by creating a variable of any name (the new unit name), into which you store its definition in terms of other units, e.g. 2_mph 'stroll' STO; you can also use other user units in a definition, e.g. 3_stroll 'run' STO. o You can then use the new unit name(s) in any custom or temporary menu, just the same as any other unit in the built-in Units Catalog. For example, { 1_stroll 1_run ... } TMENU Here's an example. Convert this using ASC\-> and save it as 'sample'. "69A20FF78E000000005046F6E6574750ADA209C2A2C2A2070000F368B01B2130 E20005046F6A756E650ADA20339201000000000000210C2A20F000046F6E6574 768B01B2130640005086F6D6562750ADA20339200000000000000510C2A20F00 0046F6E65747C2A20B0000D696E686B0168B01B2130B5000303435453047A204 7A20C2A20F000046F6E65747ADA209C2A2C2A20F000046F6E6574768B01B2130 B213047A20C2A20F000046F6A756E6ADA209C2A2C2A20F000046F6A756E668B0 1B2130B213047A20C2A20F000086F6D65627ADA209C2A2C2A20F000086F6D656 2768B01B2130B2130B2130F0DA" This is a sample directory with a custom menu. Enter the directory and press the CST key. Here you will see three units (truncated to fit the softkeys): donut, dozen, and homer. A dozen is defined as 12_donut, and a homer is a rate of 1.5_donut/min (not part of the SI system). These units may take SI prefixes described on page 10-5 of the User's Guide, so you may convert the value of 3_MW*h/kdonut into units of erg/mdozen using CONVERT, for example. The items in the CST menu have the usual abilities of unit menu objects as described on pages 10-2 and 10-3 of the User's Guide. These units can be used for math operations described on page 10-7 of the User's Guide, such as adding 2_donut to 1_dozen. Example: At your power plant, you have four control room operators who have a combined consumption rate of 2.28 homers. How many donuts will they use in 5 minutes and 17 seconds? o Enter the rate. 2.28 [homer] o Enter the time. Right-shift UNITS [TIME] 5 [min] 17 [s] + o Multiply the time by the rate (*) o Convert to dozens: CST Left-shift [dozen] o The answer is a little over 1.5 dozen. 5.8. I want `pi' to be a numeric value, not a symbol. You are using "Numeric Constants Mode". To turn this mode on or off: SX: Type -2 SF. This turns the numeric constants mode on. To turn it off, type -2 CF. GX: Go to the MODES menu (press green/right-shift MODES). Hit the key for FLAG submenu. Toggle the second flag "Constant -> symb" to turn on and off. 5.9. What tricks are there for manipulating matrices? SX: You can build up a matrix by rows using \GS+. You can take a matrix apart by rows using \GS- These two commands (\GS is Sigma (Greek E)) add and subtract rows from the SigmaDAT Statistics matrix. \GS+ takes a vector row and adds it to SigmaDAT, and \GS- takes the bottom row away from SigmaDAT. \GS+ is accessible from the STAT menu with its own softkey. \GS- can be obtained by pressing left-shift /GS+, or by typing it in at the command line. GX: The GX has many matrix functions built in. See Appendix B-1. 5.10. Can I make my HP graph any faster? Try lowering the plotting resolution by typing #2 RES. You can use larger values for faster speed at the expense of number of points plotted. In the GX Plotting Options Menu this setting is known as the "STEP" rate. Alternatively, if you have a G series machine, you could try SpeedGraph, a fast assembly language plotter replacement. See <http://www.hpcalc.org/> for a copy. 5.11. How do I plot inequalities? In the user's manual, inequalities are referred to as "truth plots". They are defined as expressions that return true (any nonzero real number) or false (0) results. In a truth plot, a pixel is turned on if the expression is true, it's unchanged if the expression is false. For example to plot the simple inequality 'X>0' you could do: TRUTH -20 20 XRNG -10 10 XRNG ERASE DRAX DRAW For more complicated examples see your manual, or on a G/GX you can type TEACH to look at some of the built-in examples. It may also be useful to plot the lines defining the outline true region. This is easily done by changing the plotting style to FUNCTION or CONIC and plotting again, taking care not to erase any previous plot. Note that unless otherwise specified, every pixel in the display must be evaluated. As such, truth plots can be very slow. If you have a general idea on which values are going to return true, you can speed up plotting by specifying a smaller x and y plotting range. You can do this by setting the "LO" and "HI" input forms on a G/GX, which can be different than the actual display range. If you are plotting the area between two equations, you speed up plotting dramatically by avoiding a TRUTH plot entirely. Store the two equations as the first two items in the current EQ list. Using NXEQ in the FCN menu will rotate the list as desired to plot both functions. Then the area between them can filled in very quickly using the SHADE key of the FCN menu (in the PICTURE environment). Another hint for speeding up Truth plots is to set the resolution, say to 2 pixels or more, which also results in a different "shading pattern". The resolution can be set with the RES command. 5.12. How do I take the logarithm of a base other than 10 or e? To take the log of a number other than base 10 or e, say log x base y, you use the formula: ln x -------- where ln is natural log (log works too) ln y A quick program to do it would be: << SWAP LN SWAP LN / >> With the input of: 2: x 1: y 5.13. How do I solve quadratic equations? The QUAD command is designed to solve expressions at degree up to two. One would expect the result of the simple expression 5=x/(1+x) to be x=-5/4. But using the QUAD command, the HP gives the complex solution (0.5, 2.17944947177) i.e. the principal value (with flag 1 set). What is the reason for this? The QUAD command is designed to solve quadratic equations. If the equation is not of the form: a*x^2 + b*x + c = d*x^2 + d*x + e The HP48 calculates a quadratic taylor series expansion which is then solved like a normal quadratic equation. The HP does the same when the equation is of a higher order. In the example above, the equation x/(1+x)-5=0 has the expansion: -x^2 + x - 5 = 0, Which has two complex conjugate solutions. However, if you multiply the equation by (1+x)/, you get: x = 5 * (1+x) Which can be solved directly with QUAD. If the equation contains the variable only once, it's the best way to use the ISOL command instead. 5.14. Why do I get a complex answers for roots of negative numbers? This typically occurs for the (2n+1) roots of negative numbers, where n is a positive integer. For example, to calculate the fifth root of -3125 you can enter: -3125^0.2 The result is the complex number (4.04508497187, 2.93892626146) or in DEG mode (4.99999999999, >36). The reason for this answer is that -3125^(1/5) has five different answers - arranged in a pentagon in the complex plane. In general, y^(1/x) has x different answers (y^x with x irrational has an infinite set of answers forming a circle on the complex plane). Since 180/5 = 36 [degrees], this is the correct principal "5th root" of the negative argument in the complex plane; the HP48, unlike older calculators, does not turn "complex mode" on or off, so all "analytic" functions in the HP48 always accept complex arguments, and always return valid complex answers if suitable. To calculate the desired solution, you have to use the right-shifted V-key with input like this: 2: -3125 1: 5 Or you can use 'XROOT(5,-3125)' since XROOT is defined to both accept and return real values only. 5.15. Why doesn't '(-8)^(2/3)' give me the right answer (4)? From: John Meyers The reason is that the function ^ accepts and returns complex values whenever appropriate, and also always returns the "principal" answer in the complex plane, which may not be real if the argument is negative, even if there exist other real-valued possible results. Here are some UserRPL programs which handle this sort of general "real power of real" question, even with fractional powers, including the sticky issue of getting the right sign. Note that the "power" argument (level 1) may be either a fraction or a real number; we use \->Q in all cases to convert it to a fraction, which may be necessary to determine the correct sign of the answer. \<< \->NUM DUP SIGN SWAP ABS \->Q IF DUP TYPE THEN OBJ\-> DROP2 ELSE 1 END 4 ROLLD * ^ SWAP XROOT \>> The version above is generally satisfactory for fractional powers which do not have a large numerator; otherwise an intermediate result might overflow, giving an invalid result. The next version is overflow-resistant, but there is sometimes a slight roundoff error from using ^ ABS: \<< \->NUM DUP2 ^ ABS SWAP ABS \->Q IF DUP TYPE THEN OBJ\-> DROP2 ELSE 1 END 4 ROLL SIGN ROT ^ SWAP XROOT * \>> Neither of the above programs ensures that its arguments are actually real; other arguments (e.g. complex) can sneak by, possibly producing meaningless answers. You can prevent this in either program by following \->NUM with OVER R\->B OVER R\->B DROP2 For example, with -8 and '2/3' as arguments, (or even -8 and .666666666667 as arguments), the answer is 4. To make the above into a user-defined function which can be used in algebraic expressions: \<< \-> p r \<< r p \->NUM \->Q IF ... END \>> \>> 'XPOWR' STO Then 'XPOWR(2/3,-8)' EVAL ==> 4 [using XPOWR() just like XROOT()] Note: There are actually two different XROOT functions in the HP48; the algebraic version of XROOT expects its arguments in the opposite order from the stack-based version of XROOT (which inadvertently gave rise to a list-processing bug in early G-series ROM versions: K, L, M and P). If you define XPOWR for yourself, as above, you will have to make sure that you use a consistent argument order for both algebraic and stack usage, unless you either make two separate functions or get into some fancy library-making, to duplicate something akin to the built-in "dual" XROOT functions. 5.16. How do I solve polynomials? Another fast way to solve quadratic equations (or polynominals of higher degree) is by using the PROOT command. Place a vector with the coefficients of the polynominal on the stack. For example: x^3 - 9*x^2 + 26*x - 24 Would look like: [1 -9 26 -24] Then press left shift, SOLVE (key 7), POLY (key C), PROOT (key A). The result is [2 3 4], which are the roots of the equation. 5.17. How can I do statistics for grouped data? Excerpt of postings from John Meyers You must replicate the individual values or you can use a weighted analysis. For weighted analysis, Joe Horn's WEIGHT2 directory which can be found on Goodies Disk 8. For weighted mean of numeric grades (or grade equivalents), with the number of credits for each course being the weight, you can use the program below. First, fill in the statistics matrix, using any of the built-in statistics applications, entering each numeric grade equivalent in column 1, and the corresponding number of credits in column 2. Then press the key for the program below, which returns three results: o Weighted mean of column 1, using weights from column 2 o Standard deviation (estimated from samples entered) o Standard deviation (of population actually entered) If you select an "X-Column" and/or a "Y-Column" different from the defaults (columns 1 and 2), then the results reflect the values in the "X-Column" using weights from the "Y-Column". The program below is a slight improvement upon WEIGHT3, in that it no longer requires SigmaPAR to exist (the standard default columns are assumed if not). Credits go to Bob Wheeler for coming up with the algorithm, and to John Meyers for implementing the following program: %%HP: T(3); @ \-> is right-arrow, \v/ is Square Root, \GS is Sigma @ WMS - Weighted Mean and Standard Deviation, HP48G/GX @ Stack diagram: ( SigmaDAT and SigmaPAR ) --> Mean, SDev(S), SDev(P) @ If SigmaPAR does not exist, then @ Col 1 (XCOL) is value and Col 2 (YCOL) is weight, by default \<< '\GSPAR' DUP VTYPE 0 < { DROP 1 2 } { RCL 1 2 SUB EVAL } IFTE 0 0 DUP2 \-> x f w d m v \<< RCL\GS x COL- SWAP DROP ARRY\-> EVAL \->LIST RCL\GS f COL- SWAP DROP ARRY\-> EVAL \->LIST 2 \<< DUP2 'w' STO+ m - * DUP 'd' STO w / 'm' STO+ m - d * 'v' STO+ \>> DOLIST m v w DUP2 1 - / \v/ ROT ROT / \v/ \>> \>>^ If all you want is the weighted mean, and not the standard deviations, then you can dispense with all of the above, and just use a shortcut posted in GD7/MATH/WEIGHT.DOC by Joe Horn (basically, it is Sum(X*Y)/Sum(Y), where Y is the weight for X). If you would rather replicate data points, then read on - however, if the "weights" associated with your data points are either very large or non-integers, then the following will be either very cumbersome or not possible, respectively. Press left-shift STAT DATA (on G/GX) to get to the menu containing the "Sigma+" "Sigma-" and "ClearSigma" commands. Press "ClearSigma" to remove the old SigmaDAT. The first data must be entered as a vector: For example [2 4] and pressing "Sigma+". Now all other data pairs are entered without the brackets just as a pair separated by a space: e.g. 4 3 and pressing "Sigma+" and so on. "Sigma-" in the HP48 does not accept data; rather, it simply removes the last-entered data point/row, popping it back onto the stack for you (the result is always one vector or scalar). If every point is removed, the statistics matrix is also deleted. Now we can understand Joe Horn's program which accepts a data point/row, in whatever form the HP48 is prepared to accept it (single number, vector, or group of numbers), plus a frequency (integer only) on stack level 1, and then appends the data point/row the given number of times. Note that you must always supply a frequency, even if it is 1, and that any meaningless "frequency" less than 1 will be treated as 1. \<< -55 CF 1 SWAP START \GS+ LASTARG NEXT DROP \>> Obviously, \GS+ and \GS- represent the "Sigma+" and "Sigma-" commands. Example: If the Statistics Matrix (SigmaDAT) already has two columns, and if we want to enter the new data pair [ 3 4 ] five times, we can simply type 3 4 5 and then press the key for the above program (don't forget to use a data vector for the very first data row). For large frequencies, as noted, you will find this to be slow, not to mention the memory required for the multiple matrix rows; however, once you have literally entered every single data row, you can then do all the regression analysis and plotting you want, without the need for additional programming. 5.18. How do I generate a function table? An easy and versatile way is to use the powerful list processing capabilities of the HP48. Generate a list with the x values, then perform the operations on that list. For example: { .1 2 2.5 5 123.4 } SQ will output { .01 4 6.25 25 15227.56 } There are also several programs/libs to create a function table. Take a look at <http://www.hpcalc.org/> and search for "MathTools" by Jack Levy or "Table" by Diego Berge. If you are low on memory or want a customizeable program you can use a tiny User-RPL program. Here are two suggestions with different forms of the output. All programs use the SEQ command, which is the key command here! (for further information read the manual). Input is for example: 5: 'SQ(x)' 4: x 3: 11 (start) 2: 25 (end) 1: 1 (step) The first mini program will output a matrix with the calculated values %%HP: T(3)A(R)F(.); \<< SEQ OBJ\-> COL\-> 1 COL\-> \>> The second one will give x and f(x) in an array %%HP: T(3)A(R)F(.); \<< 4 DUPN 4 PICK 4 ROLLD SEQ OBJ\-> COL\-> 6 ROLLD SEQ OBJ\-> COL\-> 2 COL\-> \>> -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 5.0i for non-commercial use Charset: noconv iQA/AwUBOPgDMOhzXOws+qC7EQLT0ACffjxiVgOX5r4RHhyet0+fNbC9IawAoIF2 ydoqncGJLbQpTFCPFpSZvqFK =4Ghc -----END PGP SIGNATURE-----