It looks like a calculator's a computer!


Hello all.

As I can see it, with the dawn of the 28, I feel that the metamorphosis of handheld calculator towards handheld computer is beautifully realised. Yes, yes, the 71B (as well as those Sharp 1201, Casio FX-702P, etc.) was the one of the first but, being that the 28C inaugurated such a high-level structured programming language, me thinks that the handheld computer certainly shows itself. Besides, my contention is that the structured-programming framework of RPL and System-RPL certainly provide for the qualification of the 48/50 to be bestowed handheld computer status.

Even in hindsight, to see how the 28 has spawned the 48 series which, in itself has helped to develop much more robust functionality into RPL and computer-like expandability, certainly leaves the breadcrumbs leading to computer-like characteristics.

Even more proof of this is the 50G. Compared to its elders, the 48SX and GX, in light of its symbolic math resources and capabilities tower over what the 48 Series was capable of.

So, for me, it would seem that, even at the introduction of the 28C, HP has succeeded in bridging the gap between calculator and handheld computer.

How do you see it?

Edited: 23 May 2012, 1:32 p.m.


IMHO the availablility of a high-level language (and I don't think that RPL even qualifies as such) is not required for a machine to be called a computer.

I think that the 41C can lay claim to being the first "hand-held computer", given its I/O capabilities. But I admit to being biased in this regard.


I fully agree. Once we moved into the age of mnemonics, gobs of memory by the standards of the time, alphanumerics, powerful I/O with virtually unlimited off-line storage, really the ONLY discriminating factor is the instant-on nature of the HP41. It foreshadowed today's instant-on/always-on devices by 3 decades and did it while utilizing a fraction of the power of the current crop of hand-helds.

What differentiates a "computer" from most computing hand-held devices today is form factor and purpose. Not their ability to compute. The same can be said for the 41.




That raises two questions:

Which defining characteristic of a high-level language does RPL lack? I consider it a higher-level language than C; C is really just a portable assembler.

What defining characteristic of a computer does the HP-65 lack?
The HP-65 was introduced about five years earlier than the HP-41C. Thought it was not nearly as powerful as the HP-41C, it has a processor, memory, input (keyboard), output (LED display), and mass storage (magnetic cards). What else does it need in order to qualify as a computer?


IMHO, text handling should be part of a "computer" qualification. But I must accept that, for instance, the Apollo Guidance Computer had no text abilities, and there is no doubt about its "computer" status. So my criteria may well be more relaxed, and that reopens the case (no pun intended) for the HP-65.


Turing completeness seems like a good definition. The HP-65 is almost there -- with indirection and it would definitely be, without that it will be harder to justify.

More traditionally: writable memory, executable programs, input and output. I'd probably leave off the mass storage as a definite requirement but it helps.

- Pauli


As has been pointed out here previously, indirection isn't necessary for Turing Completeness; it just makes it more efficient. Without indirection the same things can be accomplished through a series of conditionals for STO/RCL.


Point taken. This point is all the more relevant in light of that technique I was trying to develop (and posted a question here about) a few months ago, for memory register exchange on such models as the 29C which lacks the feature.


And, let's not forget the other input/output mechanism-- the card reader, giving the 65 the ability to write data and programs onto removable media, even if that only meant media readable to and from the 65 itself.


giving the 65 the ability to write data and programs onto removable media

Programs only. But the HP65 is obviously a computer.


Thanks for the clarification. Yeah, as there is an explicit 'W/DATA' keystroke on the 67, I just thought there was an automatic mechanism on the 65 that wrote data (i.e. in W/PRGM mode, a card passed through writes and, in RUN mode, data is loaded) but, I stand corrected.

Edited: 24 May 2012, 3:55 p.m.


No question about that. Besides, remember the sales brochure tagline? "A Calculator, A System, A Whole New Standard." I'll fully agree, if any calculator was to be given handheld computer status, the HP-41 family undoubtedly qualifies (and the HP-65 and 67 too)!


An HP brochure from 1974 proclaimed "This man is holding the smallest programmable computer ever".

The HP-65.


IMHO, the ability to work with:

- numbers
- text
- files and records (# with X Function optional module)
- I/O
- programs
- and the ability to use programs and functions (ROM or RAM-based)developed by others, and called easily from your own programs

were and are enough to characterize the 41C as a computer. In fact some computers of the 1980 timeframe were not as advanced on some of these abilities. I was hired by the IT department of an industrial company in 1982, and their main computer was - in some aspects - more limited than my 41C.


I ran my first automated test equipment setup from my 41cx in 1986. Some people nearly needed a change of clothes when they saw a pocket-sized device controlling a rack of equipment to test the product and log the results.

Edited: 23 May 2012, 5:46 p.m.


I love this. You were 20 years ahead of the "iPhone controller" and arguably far far far more robust.


Agreed and, coming from an Mac/iPad/iPhone enthusiast, I am honoured and glad to pronounce the HP-41 as miles and years ahead of anything Apple could dream of!


To me, any device with a CPU is a "computer".

But there's something that *does* strike me as thoroughly remarkable about the RPL line of calcs: that they were object-oriented (to a degree) at such an early moment in time.

According to the RPL Wikipedia page, the language was developed in '84.

The first release of C++ was in '85, and it was far from a mainstream language in its first years. (Or so I think. I was young and tinkering with my Atari ST in C at the time.) Yet, in '86 the HP-28C appeared.

The HP-28S appeared on my radar in '88 and I was shocked (quite pleasantly) that it had that wonderful concept later commonly known as "operator overloading". That, really, was many years before this concept became common.

A similar thing can be said about another remarkable aspect of the language: that it was/is a "functional" language (to a degree). While not entirely surprising, given the language's LISP influence, the HP-28C was probably (I'm guessing here; correct me if I'm wrong) the first hand-held machine programmable in a functional language, long before any other.

Btw. The RPL Wikipedia page could really use a History section. Maybe one of the sages here feels like starting one?

Edited: 23 May 2012, 8:01 p.m.


But there's something that *does* strike me as thoroughly remarkable about the RPL line of calcs: that they were object-oriented (to a degree) at such an early moment in time.

Early? Twenty years late: Simula-67 was object orientated and realistically there hasn't been much improvement in this since.

- Pauli


Ok, let me re-phrase:

... that they were hand-held devices that were object-oriented (to a degree) at such an early moment in time.

Any hand-held devices running Simula (or any other user-programmable language with OO characteristics) prior to '86?

Edited: 23 May 2012, 8:56 p.m.


Your microwave oven contains a CPU, but you probably wouldn't say that the microwave oven is a computer, because that's not what you use it for.

The HP-65 and its successors contain a CPU, and all of the other elements we normally associate with the general definition of a computer, and they are specifically used for their computational functionality, as opposed to that being incidental (as in the example of the microwave oven).


Depending on the user's enthusiasm, even the HP-25 can be considered a computer, albeit a minimum one:


The robust functionality that Peter Henrici's book, "Computational Analysis on the HP-25" exemplifies certainly builds a strong case and foundation to warrant the HP-25 handheld computer status.

**In addition (and I think Dave mentions it here on the HP-25 page), the 25 is what the 55 could have been.

Edited: 24 May 2012, 12:38 p.m.


... but you probably wouldn't say that the microwave oven is a computer ...

Hey, I just recently rooted mine and put Android Ice Cream Sandwich on it. It's kinda hard to explain but I use it all day long to play a version of Angry Birds that involves entering trajectories via the number pad, and, well, splashing things.

Ok. You got me there. All I meant to express was that I had no "oh, it's a computer!" realization with these machines. That part I took, and take, for granted.


Your microwave oven contains a CPU, but you probably wouldn't say that the microwave oven is a computer, because that's not what you use it for.

However, many would say it's "computer controlled" though.

The problem I have with this thread is that it is full of absolutes. At one time people were call computers (computer -- a person who makes calculations, esp. with a calculating machine).

I can also argue that a 41C is a computer (and I have), but in 1979 if you gave me a 41C and asked me if it was a computer I would have said no, because what was thought to be a computer at the time was completely different. Consider popular opinion. If it looks like a calculator, smells like a calculator, behaves like a calculator, etc...

There is no question today that an iPhone is a more powerful computer than just about every computer made in the '70s and '80s, but we do not call it a computer? No, its a phone.

HP, Casio, etc... in the '70s and '80s calling handhelds computers was purely for advertising, a way to express its powerful capabilities such as programming. Users of both knew exactly where to draw the line between calculator and computer. And that line varied by user. (I must admit that line blurred quite a bit given the cost of programmable calculators.)

I am not sure I'd classify a handheld as a computer in a general sense. Yes I know the 71B /41C/50g/etc... is a computer, but for the masses it is a handheld with a computer inside, but not a "computer".

Edited: 24 May 2012, 5:06 p.m.


...I know the 71B /41C/50g/etc... is a computer, but for the masses it is a handheld with a computer inside, but not a "computer".

A Univac 1108 running Exec 8 Level that's a computer! [40 years ago]

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