HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found (/thread-89395.html) |
HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Jacques Laporte - 03-15-2006 Hi everybody, http://www.pmonta.com/calculators/hp-35/index.html
A month later, I have found the explanation of the flaw in the exponential algorithm "exp(ln(2.02) = 2". http://www.jacques-laporte.org/HP35 bug.htm
Best regards. Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Eric Smith - 03-15-2006 Nice work. Note that the HP-35 source code from the Nonpareil package, on which you based the listing on your web site, is Copyright 2004 Eric L. Smith. The copyright notice was unintentionally omitted, which was corrected in later releases of Nonpareil (starting with r120 of the file in the Subversion repository, on 15-Jan-2004). The latest version, r850, can be obtained from ViewVC.
The simulator is GPL'd, so you should make the source code available on your site. Otherwise, to comply with the GPL, you need to accompany the executable (JAR file) with a written offer to provide the source code.
Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Karl Schneider - 03-16-2006 Jacques -- To echo Eric Smith, an impressive effort. Unfortunately for myself, I don't have the requisite background in computer science and assembly to follow it... Following the links upward, I see that you have developed an entire site containing technical discussions of the HP-35. I'd expect that they are informative... Regards,
-- KS Edited: 16 Mar 2006, 3:07 a.m.
Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Jacques Laporte - 03-16-2006 Thank you Eric for you comments.
I must underline that this work could not definitely be possible without your work Nonpareil and P. Monta’s ROM dump.
All my work is open source minded.
Best regards. Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Jacques Laporte - 03-16-2006 Karl,
Thank you for your kind comments.
Jacques.
Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Eric Smith - 03-16-2006 That's fine, no rush. I see that one of the 35 listings on your site had the copyright notice, and the other (the one you modified?) did not. I've spent more time studying your site since I posted earlier, and the more I look over it, the more impressed I am. You've done a fantastic job of explaining the algorithms. The algorithms only changed slightly from the 35 through the early Woodstock series (21/22/25/25C). The first big change to the math routines occurred in the late Woodstock era, in the 67/97, 92, 19C/29C, and maybe the 27. An overview of some of the changes is given in the November 1976 HP Journal article "The New Accuracy: Making 2^3=8" by Dennis Harms. There were some lesser changes in the 30 series, after which the math code remained fairly stable from that point through the 41 and the Voyager series. I haven't had time to do any thorough analysis of the differences. AFAIK, all of the Saturn-based calculators use essentially the same floating-point math routines, derived from the HP-71B. Some of the algorithms used are significantly different from the earlier calculators.
Eric
Merci Jacques! - Etienne Victoria - 03-16-2006 Jacques, Et merci de vos passionnants articles qui m'ont fait réfléchir et rêver durant les belles années de l'OI -- et je ne parle pas du "catalogue publicitaire" diffusé aujourd'hui! Bien cordialement Etienne ------------------------------------------------------------- Jacques, Thank you for your great contributions to "L'OI" newspaper. These articles made me think and dream during many beautiful years. Friendly yours.
Etienne
Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - tomcee - 03-22-2006 Great Work and highly informative!!! Thanks! I have found that the links on your pages to Volder, Meggitt and Walther seem to be broken!
Regards, Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - bill platt - 03-24-2006 Awesome. This is the sort of thread that makes this forum so informative!
Re: HP 35 ROM V2 "exp(ln(2.02) = 2", explanation found - Jacques Laporte - 03-25-2006 Hi and thank you, TomCee. > I have found that the links on your pages to Volder, Meggitt and Walther seem to be broken!
Yes, sorry ; I've corrected a few of them. Re: Merci Jacques! - Jacques Laporte - 03-25-2006 Hi Etienne,
HP 35 was -and still is- a so brilliant machine! |