HP 50g: Mantissa of an Extended Real - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: HP 50g: Mantissa of an Extended Real (/thread-9246.html) |
HP 50g: Mantissa of an Extended Real - Gerald H - 10-07-2017 12:23 PM Does anyone have a programme to get the mantissa of an extended real on the 50g - the shorter the better? RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-07-2017 03:24 PM Here is my attempt at a solution, but I fear the programme is too large & slow: Code: :: RE: HP 50g: Mantissa of an Extended Real - DavidM - 10-07-2017 04:48 PM (10-07-2017 03:24 PM)Gerald H Wrote: Here is my attempt at a solution, but I fear the programme is too large & slow: This is smaller and faster, but there's probably still a better way: Code: :: RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-07-2017 06:19 PM Excellent, DavidM! Much faster than any programme I have seen to find extended mantissa. Deals with %%0 & negative powers correctly, only critique is negative numbers remain negative. RE: HP 50g: Mantissa of an Extended Real - DavidM - 10-07-2017 06:33 PM (10-07-2017 06:19 PM)Gerald H Wrote: ...negative numbers remain negative. I'll admit that I didn't test this out extensively, but I did try at least one negative number and the sign was changed to positive (as it should have been, due to the DAT0=C P step). What did you test with this that didn't result in a positive mantissa? RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-07-2017 07:38 PM Various negatives,eg %% -7.7E1, %% -1E0, %% -1E66, the negative sign is consistently retained. I haven't found one negative number that shows a positive mantissa. RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-07-2017 07:46 PM Sorry, I must have erred in copying the instructions, on recompiling the negatives are dealt with correctly. RE: HP 50g: Mantissa of an Extended Real - DavidM - 10-07-2017 07:55 PM (10-07-2017 07:46 PM)Gerald H Wrote: Sorry, I must have erred in copying the instructions, on recompiling the negatives are dealt with correctly. No problem. You had me really scratching my head for a while there, though. I should have included the checksum/byte count as a safeguard. Here's the commented code, in case anyone is interested. I did swap two lines in this one to make the flow more consistent (it doesn't make a difference in the result, of course). Checksum: FAECh Bytes: 41 Code: :: RE: HP 50g: Mantissa of an Extended Real - Arno K - 10-07-2017 09:36 PM Quite informative, thank you. Arno RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-08-2017 06:42 AM Some background: You may remember a library for the 48G http://www.hpcalc.org/details/1243 called EXMATH which took control of screen & keyboard & created an RPN calculator working with exponents up to 49999. I have updated the library to work on the 49G ver 1.19-6 & 2.10-7 & on the 50g ver 2.10-7, adding some extra functions & trying to improve performance. I am confident that my own programming is not optimal & am very grateful for assistance. RE: HP 50g: Mantissa of an Extended Real - Arno K - 10-08-2017 07:43 AM Helping with things like that is for the time being way beyond my abilities (and the amount of time I can invest), I am refreshing my URPL which hadn't been used for mor than 10 years, I have recently started looking into the available SRPL books and I like writing little programs. So I usually have a close look at your programs which always seem to be very effective. Arno RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-09-2017 10:17 AM The annotations are very welcome, DavidM, as I am fearful of writing any assembly language code & regard its effect as magical. Writing programmes in User & Sys RPL requires much less initiation, really just a mechanized form of algebra. I think, Arno, that the change from User to Sys is not so big a step & the gain in speed is well worth the effort. I look forward to you writing some interesting programmes. RE: HP 50g: Mantissa of an Extended Real - DavidM - 10-09-2017 02:45 PM (10-09-2017 10:17 AM)Gerald H Wrote: The annotations are very welcome, DavidM, as I am fearful of writing any assembly language code & regard its effect as magical. I think of writing Saturn code in a similar fashion to building furniture out of Lego blocks. It can be done, but you better have both a good reason and a good plan or you'll go insane before you finish it. Although I rarely choose assembly solutions as a first approach, this one seemed like a perfect fit -- simply setting the exponent and sign fields to 0 was all that was needed, and I knew that would be fairly easy (and fast) in assembly. (10-09-2017 10:17 AM)Gerald H Wrote: I think, Arno, that the change from User to Sys is not so big a step & the gain in speed is well worth the effort. I look forward to you writing some interesting programmes. I agree! RE: HP 50g: Mantissa of an Extended Real - franz.b - 10-10-2017 06:32 PM (10-08-2017 06:42 AM)Gerald H Wrote: ... where can we find it? RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-10-2017 06:39 PM Nowhere as yet, should however probably shortly appear at http://www.hpcalc.org/ RE: HP 50g: Mantissa of an Extended Real - Gerald H - 10-13-2017 05:41 AM (10-10-2017 06:32 PM)franz.b Wrote:(10-08-2017 06:42 AM)Gerald H Wrote: ... Now available at http://www.hpcalc.org/details/8702 RE: HP 50g: Mantissa of an Extended Real - franz.b - 10-13-2017 06:52 AM (10-13-2017 05:41 AM)Gerald H Wrote:(10-10-2017 06:32 PM)franz.b Wrote: where can we find it? thank you very much! I saw it yesterday in hpcalc news and today in hpforums posts! |