HP Forum Archive 12

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HP49G: Lost command remedy Message #1 Posted by Juergen Rodenkirchen (GER) on 30 Apr 2003, 2:20 a.m. Hi all! The other day I discovered that I apparently had "lost" 2 commands, namely "->LST", "->ALG", on my HP49G, ROM 1.19-6. That is, they neither appear in the catalog nor can they be executed by typing in manually any more. BUT, I've a program loaded that includes these commands AND it works just fine. So, I guess, the commands actually are still there in ROM but the OS doesn't recognize them any more (broken pointer?). I'm not sure, but I think - apart from Re-Flashing the ROM - a work-around could be to isolate the commands in question from the program and to put'em in a cst-menue. Even better, one could use SYSEVAL to execute the commands in ROM from a custom menue? If this would be a remedy, does anyone know the ROM address of the commands mentioned? Regards, Juergen

Re: HP49G: Lost command remedy Message #2 Posted by Vieira, Luiz C. (Brazil) on 30 Apr 2003, 3:09 a.m., in response to message #1 by Juergen Rodenkirchen (GER) Hi, Jurgen; I took a look at the HP49G's [CAT] and I found '->LIST' in both 1.18 and 1.19-6. I have a second HP49G in hands for now and each one has a different O.S. version. I was not able to find '->ALG' in any of them, nor '->LST'. May I ask a silly question? Forgive me if it is too silly, but are you sure they are not part of an installed library? I remember you mentioned having some stuff installed in your HP49G, as you bought it as a second hand. Have you already checked for it? Maybe you need to init ports again after O.S. updating so you'll have them "activated". Do you remember what were those commands for? Best regards. Luiz C. Vieira - Brazil

Re: HP49G: Lost command remedy Message #3 Posted by Juergen Rodenkirchen (GER) on 30 Apr 2003, 5:39 a.m., in response to message #2 by Vieira, Luiz C. (Brazil) Hi Luiz! It's sort of "reassuring" that 1.19-6 seems actually to miss these both commands and it's not a ROM corruption of my copy (no libs installed anymore, b.t.w.). Anyway, it's a great pity that those commands are not in the ROM (anymore?): I'm almost sure that they were contained in OS 1.18. And, as said, I do have a program that uses those commands successfully (downloaded from somewhere)!!! That - to my opinion - means that they definitely do exist in ROM and that there MUST BE a ROM address for SYSEVAL? Or are they after all just programs that I've created during the math marathons and which are not in the current path anymore? I'm sorry, can't remember; I've to double check that later ... As for the commands itself, they have the following valuable functionality: ->LST: Takes an Algebraic Expression apart in a list enabling you to execute it afterwards by means of RPL ->ALG: Is the opposite of ->LST: It takes a list of objects (like the above) and creates an Algebraic out of it. Regards, Juergen

Re: HP49G: Lost command remedy Message #4 Posted by James M. Prange on 30 Apr 2003, 5:30 a.m., in response to message #1 by Juergen Rodenkirchen (GER) They're part of library 256, the "hacker's library". Try 256 MENU to have them available as operations, or better yet, 256 ATTACH to have them available as commands and show up in the catalogue. Note that these are considered to be hacker commands, so if you're using them, it might be wise to have a recent backup. They seem to have some argument checking, but I wouldn't bet that you couldn't get a "Try To Recover Memory?" if you misuse them. I doubt that SYSEVAL would work for these; more likely LIBEVAL. (I'd consider these to be hacker commands too.) \->ALG, \->LST, and \->PRG can change a composite object (algebraic, list, or composite) from one type to another. Try putting '1+2+3' on the stack and executing \->LST followed by \->PRG (note that the resulting program lacks the UserRPL "program delimiter" commands), followed by \->ALG to get back to what you started with. Also note that you can change a composite object to a "MetaObject" (the elements followed by the count on the stack) with the COMP\-> command, and change the MetaObject back to a composite with \->ALG, \->LST, or \->PRG. Note that the composite objects are much the same "on the inside", but have different prologues, and therefore different types and behaviour, and are displayed differently. Regards, James

Re: HP49G: That's it!!! :-) Message #5 Posted by Juergen Rodenkirchen (GER) on 30 Apr 2003, 5:42 a.m., in response to message #4 by James M. Prange Woaw! Yes, that's the solution! Thank you so much, James!!! :-) Regards, Juergen

Where can I find literature... Message #6 Posted by Vieira, Luiz C. (Brazil) on 30 Apr 2003, 6:08 a.m., in response to message #4 by James M. Prange Hello James, folks; is this sort of information available for download somewhere? I tend to use and access basic, "public-domain" documentation, but I see it's time to go beyond. I'm thanked for any information about these "extra" subjects. Luiz C. Vieira - Brazil

Re: Where can I find literature... Message #7 Posted by James M. Prange on 30 Apr 2003, 7:45 a.m., in response to message #6 by Vieira, Luiz C. (Brazil) Try "Programming in System RPL" (and the errata for it), available at Eduardo's "HP Knowledge Base", http://membres.lycos.fr/ekalin/index.php. There's probably some information about this available at http://www.hpcalc.org/, and of course you could search the newsgroup from http://groups.google.com/advanced_group_search?group=comp.sys.hp48. By the way, if you install the extable library (extable.HP), library 258, from extable.zip, then library 256 will be attached whenever you do a warmstart. Be warned that the extable library is big; 89998 bytes, so you might be better off using XModem to download it to the 49G. Use the filer to move the libary to flash, and then do a warmstart. The extable is basically an entry points table; it cross-references supported SysRPL entry points (addresses) with SysRPL command names (otherwise unnamed on the calculator). Very handy if you want to do any SysRPL progamming on the 49G itself, or even if you just want to look at a SysRPL program with flag -85 set. Also good for looking up the address of a SysRPL command for use with SYSEVAL. extable.zip is available at http://etud.epita.fr:8000/~avenar_j/hp/49.html, and includes tools for making your own entry points table including unsupported (but, I hope, stable) entry points, or if you don't like the names that HP uses, you could invent your own.

Re: Where can I find literature... Message #8 Posted by James M. Prange on 30 Apr 2003, 7:54 a.m., in response to message #7 by James M. Prange Oh my gosh! I forgot to mention that all of that's TOP SECRET! Just kidding! It can be a bit hard to find, but some people have explored their calculators quite a bit and are willing to share their discoveries with ordinary users like us.

Thanks a lot!! Message #9 Posted by Vieira, Luiz C. (Brazil) on 30 Apr 2003, 11:52 a.m., in response to message #8 by James M. Prange ;^)

Re: Where can I find literature... Message #10 Posted by Juergen Rodenkirchen (GER) on 30 Apr 2003, 9:17 a.m., in response to message #7 by James M. Prange A BIG thanks for sharing information :-) Best Wishes, Juergen

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