Driving force of HP Calc function sets


Hello all,

Although I can see why HP chose the function set of the HP-35 and 55, what propelled HP to have a function set which was more limited (i.e HP-45 versus TI's SR-51)? For example, although the HP-27 had a more robust statistics package, why wouldn't the HP-25 or 19C/29C have that enhanced statistical function set since it would have made these more capable programmable calculators to satisfy those who wanted some of the HP-27 in a programmable calculator?

Edited: 26 July 2012, 12:55 a.m. after one or more responses were posted


The HP-45 came out in 1973. The SR-51 came out in 1975.


Yes, yes. After visiting the Datamath site, I discovered that chronology. Thanks

Edited: 26 July 2012, 12:58 a.m.


I did not have to check any web sites. I lived those years.

I was a senior in EE at Ga. Tech in 1973 when the HP-45 came out, and in 1998 I wrote an article in the HP Memories Forum about a lucky fellow student who was able to buy an HP-45 ($400 plus $16 sale tax...that's $2,150 in 2012).

I bought a $225 SR-51A at a US Navy base exchange after military discount for $175.00 in August 1975. That's $750 in 2012.

I couldn't afford an HP-35 or HP-45 or any other scientific calculator while I was an EE student. I got a used HP-35 (Red Dot) when I traded a TI-58 for it to a shipyard engineer in 1978. I got a used HP-45 in 1987 at a ham radio flea market for $5.

The early days were the exciting days...but our toys were very very expensive. I still have a hard time believing what a $110 HP 50G or even a $12.50 Casio fx-115ES Plus today can do for the price. And then there's those Android Smartphones!


So accounting for depreciation, etc. The $125 you might pay on ebay to get a good HP 11C is a good bargain? ;)


Depends on comparison :-) Compare it with its price at product launch and it's a good bargain. Compare it with a scientific of today featuring approximately the same function set and it's way too expensive.

Walter (who studied when the HP-45 was launched and could only dream of one)


As did I. I was six when the 35 came out but, it wasn't until the SR-56 that I had a real firepower calculator. While residing in the TI camp for a while, I started on the HP trail when the 32E came. After that and the 34C, I was hooked.

Although I was not so keen on the HP camp until my 32 and 34, for the past 20 years I've been looking at the calculator race in more detail nowadays moreso than I've done before. So yes, in hindsight, I am very interested in the decisions of functionality that go into calculator design. And although I may get my timeline in an asynchronous perspective, thanks for correcting my historical missteps.

Edited: 26 July 2012, 3:31 p.m.


With the dates given in this museum, you can draw the timeline of HP calculators yourself :-) This may save you sometimes ;-) And, BTW, the function set of the HP-27 could cover a bit more math than the one of the HP-29C since it wasn't programmable ...

Edited: 26 July 2012, 4:13 p.m.


As did I. I was six when the 35 came out but...

I would not expect that that one in the early stages of elementary school would follow the details of handheld calculator development all that closely.

Many of us in the 1970s engineering community did, some passionately.

By around 1980 these devices were tools more than toys. Since the HP-67 and TI-59 of 1977, only the HP-42S and the HP49g+/HP50g have been truly remarkable to me. From TI-world I have two top-line TI-92s (HW1/1999 and HW4/2008). I hate these and other TI products from the past 30 years.

Maybe the apparently innovative HP39gii will bring some interest back...if it ever comes to the US.


Well, born with hydrocephalus, contact sports were OUT OF THE QUESTION! So, I became a bookworm and was very fond of mathematics. In '72, I was six and, as the calculator revolution was underway, my grandfather got me my first calculator, a TI 2500. A Bowmar Brain came later. Although I formally took the classes going up to Calculus, I taught myself some higher math before I was supposed to take it in school. Then I spent more time using my sister's SR-50 than she did.

Being that I loved mathematics so much and my grandfather was very protective and caring, he spoiled me in my calculator fascination. During which time, I taught myself how to program the ones I had (SR-56, TI-58C). Thus, the mathematician, collector, programmer was born.

Later, in 1978, with the TK Enterprises bible, 'Everything You've Always Wanted to Know About RPN...,' I taught myself RPN. Petitioning for (and got) an HP-32E for my 13th birthday and 34C later for Christmas, I was HOOKED on RPN. Ever since then, I've acquired whatever HP scientific and graphing calcs HP released.

Niow with the help of eBay, I've been able to fortunately add the HP Classics and Woodstocks to my cottage museum. Don't worry, Dave Hicks holds claim to the truly authoritative museum.

There you go.

Edited: 26 July 2012, 10:40 p.m.


In the "since the HP-67 and TI-59 of 1977" category, I would claim that the HP-41C was truly remarkable. The 41CV, 41CX, and even the 42S were only incremental improvements. In fact, although it offered some new capabilities, the 42S is a significant regression due to the lack of I/O.

Similarly I would claim that the HP-28C was truly remarkable compared to its predecessors, despite having too little memory. The 28S, 48, 49, and 50 were only incremental improvements over the 28C.

Edited: 26 July 2012, 11:09 p.m.


I was expressing only how I personally felt, having been exposed to HP handhelds since 1972.

I found the increments in capability by both HP and TI to be very interesting and exciting in ways more than just that required for my engineering work 40 years ago. After 1980 great machines became commonplace...but now just tools, including my HP-41C, HP-41CX, HP-15C, HP-12C, HP-28C, HP-28S, HP 48SX, HP 48GX, HP 32Sii, HP 38G, and HP95LX. Just very capable tools. The HP-42S and HP50G are the only HP machines of the many I've purchased since 1980 that retain my interest to this day.

Others have very valid reasons for feeling differently, especially those who came later in the calculator development curve and thus did not burn out after the first ten years of really revolutionary and technologically exciting products by HP and TI showing up every few months to overwhelm expectations. It's like appreciating all the wonderful advances in space exploration that have taken place in the last 45 years. After Apollo 11 though, everything else has been almost anti-climax. But once in a while there's something that really stands out, such as the Hubble Telescope. IMO, the HP50G is like NASA's Hubble Telescope. Hyperbole?? It's not intended to be.

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