The Great Debate of '76


Hello all,

I've been wondering. When TI's SR-56 and SR-52 came out, which HPs were out that could measure up? I know that from some of the TI sales brochures, the comparisons would be SR-56/HP-25 and SR-52/HP-65. But, were these appropriate comparisons? Frankly, for example, the SR-56 should've been compared to the HP-29C and the SR-52 should've been measured against the HP-67. Perhaps these models were not available simultaneously or, perhaps they were. In any event, were the TI comparisons an accurate representation?

Edited: 16 Apr 2012, 10:20 p.m.


Two different dynamics might be considered:

1. Which company had the most powerful handheld machine at ay given time;

2. Which company had the greatest 'horsepower per dollar

Generally #2 goes to Ti pretty consistently--and don't forget Sharp/Tandy in that category...


I was in high school at the time, and I remember well all the TIs that crapped out after a relatively minor fall. I also remember how impressed I was at the time with the obviously superior build and design quality of the HPs. I bought an HP-55 shortly after ( for $425 - a minor fortune for a high school kid in '76!), and took it back to the store a week later to exchange it for the new HP-25. I once hurled that one across the cafeteria at a fast departing friend who had just jabbed a pencil into my palm. I was horrified at what I had done, but the HP took the abuse and continued working for 10 years after that. I finally replaced it with a 28S in 1988, but the build quality on that one was rather disappointing. My vote goes to HP hands down...


Back in April 1976 (near the end of our senior year in high school), a friend and I combined a phone order from Sharp Photo in New York to buy two calculators: an HP-25 and an HP-55. My friend chose the HP-25 because it was cheaper and had better programming (merged keystokes and more conditionals) while I chose the HP-55 because it had better statistics, linear regression, unit conversions, and the timer. I also felt the HP-55 was a more robust design. My friend paid $175 for the HP-25 and I paid $275 for the HP-55.

Each of us made the right choice for the directions we were heading. My friend went to the US Naval Academy, became a nuclear engineer on submarines, and now has a PhD in Computer Science. I'm sure he owes it all to the enhanced programming features in the HP-25. :-) I am a civil engineer and used the heck out of the features I deemed important while in college, even the timer. We both learned to write "tight code", but mine had to be bit tighter.


Well yes, you're right. In the day, for that price range arena, and with HPs being higher in price than TIs ($800 for a 65, compared with $300 for an SR-52) a working professional or college/high-school student working an extracurricular job who had their sights on an HP would more likely buy HP than a parent of a high[school/college kid who wanted a calc. Further, I think that in light of TI's algebraic logic, the appeal for the student market would lean towards AOS than RPN. Conversely, those who were mathematically- or scientifically-minded would be more attuned to understanding and appreciating RPN than another who would see RPN as some 'backward' logic and very cryptic way to solve a calculation. I remember actually seeing a TV ad in the 70s (for either the SR-50, SR-52/SR-56) of someone trying to use an HP and the tagline was "There's got to be a better way."

Edited: 17 Apr 2012, 1:13 a.m.


Hi All

One thread in the Archives comparing the 52 and 67.


Whoa! thanks for the compass point. This read should prove interesting.



That were the years of the 'calculator war', meaning every once and a while either HP or TI were regarded leading featurewise. Usually the lead changed every few months. What remained constant (from a user's point of view) was

  • the superior build quality of HP, in particular regarding the keyboards, and
  • the higher calculation power per monetary unit of TI.
IIRC, this 'war' pretty much ended with the HP-41C. TI withdrew from the scientific market and turned to educational area. After many years, this looks like a wise strategy now, but only because HP didn't maintain its market ... :-/

Just my personal memories and views.


I remember like yesterday when the HP65 was king and then in the Spring of '76 I saw my first ad in a magazine for the SR-52 and was amazed. That lead only lasted a short while until the HP67 was released in Summer. A year later, TI announced and shipped the TI-58/59 and took the lead again. The 41 hit the street on 7/16/79, and things swung back to HP. A few years later at the Summer Consumer Electronics Show in Chicago at the TI booth, we got to play with the newly-announced TI-88 and it looked like it might be a decent competitor for the 41, but they changed their mind and decided not to release it. I think the HP/TI battle pretty much slacked off after that point. HP released the 42S in 1988 without I/O and TI took a "left turn" did the TI-74 and TI-95 Basic machines. It didn't seem like they saw each other as arch rivals after the mid 1980s.



Makes me wonder what the TI-88 and (if you remember from its mention in the Charles Sipple book "Programmaable Calculators' and several other sources) the Novus 7100 could've been.


Makes me wonder what the TI-88 and ... the Novus 7100 could've been.

It was the National NS7100 which spawned the PPC ROM for the HP41, believe it or not. Richard Nelson was recruited to beta test the 7100 and it had a port for a module like the TI59 (but before the 59 saw the light of day). He suggsted a "programmer's" ROM module as one of the ideas for that machine. After the 59 was released, National cancelled the 7100 and the idea for a routines ROM was shelved until the 41 made it possible again. Richard's NS7100 prototype remained in the PPC clubhouse when he left the organization around 1983 and we don't believe that it survived PPC's demise (or else it secretly wound up in somebody else's collection)...



I don't know if it would have sold well, or have been considered pivotal in retrospect, but i sure would have liked to have had one of those 7100s. It would have out-done the TI-59 and the hp67 in terms of memory storage and usability and outdone the 58c because it was RPN.

I'd still like to have one but now, of course, we have the wp-34s.


To see oursels as others see us!
It wad frae monie a blunder free us,
An' foolish notion."

In those days users of machines with A.O.S. were bemused by what seemed to be the curious attachment of the HP community to RPN, which some said was an acronym for Really Pathetic Notation. Personally I found that ideas such as "Reverse Polish" and "solving a problem from the inside out" reminded me too much of the book that fascinated my children in those times Insde, Outside, Upside Down.

Richard Vanderburgh, the editor and publisher of 52 Notes summarized the unusual loyalty of HP users to their machines on page V2N4P1 with the statement

It just has to be better since I paid more for it


If you can read French, I have an interesting article (PDF) from "Science & Vie" comparing HP-67 versus TI-59 (5-1/2 pages).



Can you post the article somewhere? It would be interesting for the community, too. If you can't host the file I can do that or arrange something with the above mentioned web site.


Hi Marcus,

I could send you the doc by E-mail, if you want. I can not host the file. This article has 36 years old, I guess.



Send it to marcus at mvcsys dot de.




Thanks. I have to check but it looks like I already had a copy in my archives which must have come from somewhere, most probably from I'll compare them and post a link if I can find it.


The years 1974 to 1978 were my most intense period of new calculator purchase and use.

In 1976, HP had the HP-65, 25, and 55 programmables. TI had the SR-52 to compete with the HP-65, and the SR-56 to compete against either the HP-25 or HP-55, though the HP-55 never had enough general appeal to be worth discussing. I bought an SR-56, and I consider it today still to be superior to those HP offerings except for the mag card HP-65. But the SR-52 was a more-than-adequate foil to the HP-65.

By 1977, the HP-67 and HP-97 were available and grossly superior to the TI offerings for most purposes. But TI quickly countered with the TI-59 with an extraordinary amount of RAM (for the time) and large mag card the innovative solid state software modules. It was also only two-thirds the cost of the HP-67. I managed to scrape up enough funds to buy first the HP-67, then the TI-59. There was no doubt in my mind that although the 67 was far more efficient for program size and built of far higher quality, the TI-59 was the 1977 state-of-the-art (as long as I could keep one working...I went through five TI-59s and three PC-100s in three years).

Because of the reliability problems with the TI products, I wrote my critical applications for use on a S5W naval propulsion reactor on the HP-67, and I had my ship command buy a HP-97 to execute my programming when I left the service. HP quality definitely won over TI quality.

One area often left out when comparing calculators of this era is the availability of printed output. There was no way to get printed output from the HP scientific programmable hand-helds. The only possibility was using the larger and much more expensive HP-97. OTOH, TI produced the SR-51, SR-52, SR-56, TI-58, and TI-59 hand-helds that could quickly be positioned on the PC-100 print cradle (through the battery pack port) for effective and economical thermal paper printer output. The PC-100 also powered the calculator from AC power at the same time. That was great for programs running unattended for long periods of time. The combo of the TI-59 and the PC-100, along with a selection of solid-state software modules, resulted in performance that grossly exceeded the best that HP had to offer by the early 1978. That situation lasted until the era of the 1979 HP-41C, for which TI never marketed a satisfactory competitor as a scientific programmable.

Today, the 1977 situation is reversed. In 2003, the HP 49g+ introduced massive amounts of storage in the form of SD cards, along with excellent display quality and support for IR output to a small inexpensive printer. It integrates a sophisticated set of supplied low-level development tools, and (since the 50g) it can be powered externally by USB cable. The TI 89 competitor has during the same time been through several hardware revisions (now hardware version 4) and still has no SD card capability, no easy way to print, no easy way to power externally, no included low-level development tools, and an absolutely horrific quality of LCD.

Today's HP 50g towers over today's TI 89 Titanium (HW4) in capability more than the TI-59/PC-100 did over the HP-67 in 1977. It's just too bad that handheld calculators are not very important any more.

Edited: 18 Apr 2012, 2:29 p.m.

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