|Re: Where is linear regression on an HP-41|
Message #19 Posted by Mike Morrow on 14 Aug 2012, 12:49 p.m.,
in response to message #18 by Palmer O. Hanson, Jr.
I wrote: "Other than the PC-100 capability of the SR-52, it had nothing to recommend it over the 1976 HP-67...and never would I consider it otherwise comparable to the HP-67."
Curiously enough, when the HP-67 was released the editor of 52 Notes wrote much the same sort of thing about the HP-67 -- disappointing, and no reason to buy it.
That editor's statement was obviously unburdened by the weight of facts. It would be true in a comparison of the HP-67 to the TI-59...but not to the grossly less capable SR-52.
I had my ship purchase a SR-52/PC-100A for use in the nucleonics lab in early 1976, before either the HP-67 or TI-59 was available. When the HP-67 appeared later, I found it to be a great advance over the SR-52 in every way except printer capability and (as you mention) the greater accuracy of the SR-52. At the cost of more than six weeks of my lieutenant(jg) pay I bought a personal HP-67, my first HP, with a few accessories. The SR-52 was clearly out of the contest, even though my personal calculators before then were all TIs purchased from 1974 to 1976...the SR-50, SR-51A, and SR-56.
The TI-59 in 1977 was a stunning product at a very competitive price (except for its ugly industrial design and color scheme). If it had been available before I purchased the HP-67, I doubt that I would have purchased an HP-67 until experiencing all those many failures of TI quality. I bought my personal TI-59/PC-100A in 1977, and I liked it greatly because of its capabilities. The TI-59 $300 price in 1977 was equivalent to almost $1200 today, compared to the HP-67's $450 price, equivalent today to $1700.
I have never understood all the horror stories about the TI-59.
The only thing to understand is that quality of manufacture was very obviously lacking...failures occurred under very benign and non-challenging environmental conditions. My first TI-59 died within a year. The replacement died within six months, as did the subsequent replacement and my first PC-100A. When in 1981 my fourth TI-59 and second PC-100A died, I wrote the Chairman of TI, Mark Shepherd, describing my personal history with this product. I'm sure he never saw the letter, but I received a letter from an underling stating that a newly-made TI-59 and PC-100 would be tested and burned-in and then sent to me without cost (I had to pay for some of the earlier replacements), along with the address of a TI engineer who would be examining my failed units. The printer replacement was the less-capable PC-100C.
I required hardware to serve reliably for fairly significant submarine reactor, nucleonics, equipment performance monitoring, and navigation applications. The TI-59 failed repeatedly...the HP-67 did not. That was a real shame, because the TI-59/PC-100A capabilities were better suited to my needs than those of the HP-67, even after taking into account the inefficiency of the TI AOS which resulted in programs typically at least 40 percent longer than when implemented on the HP-67.
I worked at Honeywell. The company participated in TI's Productivity program where any employee could get a TI-59 of his own by taking a short introductory course.
I read of those programs with envy back then. TI had no such offerings for US Navy people. :-)
I had one friend who refused to take the course and get his TI-59. He insisted that his ditsy little HP-25 was better because it used RPN. We all thought that was more than a little odd.
Indeed. The HP-25 was useful only for a very very limited set of applications, compared to those possible on the TI-59. And TI never was so incompetent as HP to design a battery charging system that was guaranteed to destroy the calculator under conditions that were bound to occur naturally and inevitably...a shameful failure of HP to meet a trivial engineering problem from the here-so-revered mythological Bill Hewlett era!
During the period from the release of the TI-59 to the release of the HP-41 I knew of no one who thought that the HP-67 was a serious competitor for the TI-59. The editor of 52 Notes had a comment on that. He said that the HP users looked at their machines and thought "It just has to be better since I paid so much more."
Experience...the best teacher...taught me how wrong sophomoric conclusions as these from that editor can be. In fairness, it is not likely that many TI-59 users had applications that required use in real-time to reliably produce results that then were utilized immediately in a major process, as my applications (like a reactor high power calorimetric, or a sea-traffic contact motion analysis) often required.
I spent a lot more "hobby time" with my TI than with my HP. It was a much more interesting system when it worked. I really liked the TI-59, but I never lost sight of its oft demonstrated lack of reliability. I stopped writing programs for the TI that were required for professional purposes.
The HP-41 was clearly better than the TI-59 in many ways. But I didn't like RPN and I worried about the accuracy of ten digit calculations instead of 13.
I'd say that the HP-41C series was better than the TI-59 in every way except the accuracy issue. That issue remained with all HP machines until the appearance of the Saturn-based models...so HP recognized it eventually.
I had purchased a Radio Shack Model 100 which could support some serious plotting capability and had switched to it for most of my work in inertial navigation until I retired.
The Model 100...that's a real milestone from 1983 regardless of its slow speed and the old-even-then 80C85 uP. I've got a couple of them that I used professionally in commercial nuclear plant engineering applications between 1984 and 1987. I loved its double-precision Basic in which some surprisingly sophisticated applications could be implemented.
Edited: 14 Aug 2012, 1:42 p.m.