Re: 16C Cheap?


Patience, young grasshopper... patience. The price for most HP calculators is determined in the last 10 seconds.


wondering why 16C wasn't popular.
Maybe because of that narrow LCD display.

It should be twice that width, if trying to
display numbers for conversion to binary, etc.
esp with formatting spaces.


Name a calculator that has a longer display.


your question is illogical. Naming another width of display, on some other calculator, has no bearing on the optimal width of the display for a "programmers calculator" such as 16C.

The optimal width of the display, may not match to the width of the displays that were sold on other makes and models.

Therefore, even if no display were wider than on 12C, 15C, 16C, there may be an optimal display width that nevertheless is wider.

Manufacturing methods today make it inexpensive to prepare displays of varying widths. Indeed, they may even be paying more for such a small display, in comparison to a larger one (since the small display may
be special order, the large display may be a standard item).

"Mr. Spock, your logic is impeccable. We are in grave danger."


The suggestion was that it was not popular because the display was too small.

That pre-supposes that it has any value at all. A valuable item will be used.

That being the case, if such a calculator is of value, and it is suggested that it's not used because of the display length, then the implied implication for not using it is that there is another that has a longer display. Because, something of value that is needed will be used.

I simply asked for the name of the one that had the longer display.

Note: A valuable and necessary device will be used, regardless of display length, if that's the only choice.

Edited: 12 June 2003, 6:04 p.m.


people dont like 16C. Point taken. I had no idea, never owned one, am not a programmer.

Could it really be true that they have no value? Somebody must like them, if only on some other planet somewhere ......


Hi, Norm;

I'm suspicious, but I have two of them. Think of one of the best tools ever made, but it was too specific and the precise activity it was developed for had only this "dedicated" tool available at the time it appeared. When I was an E.E. student, I was the only one in the hole campus to have one. Guys were amazed how funny it was finding the resulting data in a digital design without building it. In a time the first 16-bit processor were ruling, the HP16C could handle up to 64-bit words, and a few up-to-128-bit-word operations.

As Grant Goodes' post shows, it is still being used in the way it is expected to be. I just imagine that there are few places where it happens.

My thoughts.

Luiz C. Vieira - Brazil


*I* certainly like the 16C! It was my first HP calc, and if I could keep only one, it would be that one! Besides the sleek lines and solid construction that it shares with the other Voyagers, it has functions I've never seen on any other calculator. While many calculators let you convert between number bases, not many let you switch all operations to a particular base and then use all the calculator's other functions normally with that base, without having to enter special prefix keystrokes before numeric entries.

Some of us still work with mainframes and have to deal with large dump files full of octal or hexadecimal gibberish. I also work with networks of Unix systems and sometimes have to decipher the contents of TCP packets or debug driver problems. How many handheld calculators allow you to take a string of hex digits, convert them to binary, shift all the bits a specified number of positions, perform a logical AND against a bit mask, etc. -- all after setting the wordsize and complement mode to match the processor of the system you're debugging! All that (and more) is easy with a 16C.


Wayne Brown wrote:

Some of us still work with mainframes and have to deal with large dump files full of octal or hexadecimal gibberish.


Hey, that sounds familiar! In the mid-to-late '80's, I maintained Fortran software running on Sperry mainframes. Sperry (which merged with Burroughs to become Unisys during that period) was somewhat unorthodox in many respects, and they used 36-bit words with ones-complement integers. (Even then, twos-complement was favored.) Memory dumps were rendered in octal, which fit the 36-bit words.

One of the programs I wrote for my 15C (purchased in 1983) decoded a 12-digit octal representation of a floating-point number. The program accepted the three-digit exponent and the nine-digit mantissa into the stack.

The 15C program worked fine, but I now see that I could have written a slicker program for a 16C, with its word-size and octal modes. The 16C also had the correct integer conversions built in!

I bought a 16C on eBay a few months ago, but hadn't known of its existence back then. The 16C is the only HP unit I know of that offers ones-complement mode. The 41C Advantage assumes unsigned integers for its base conversions; all other HP's with base conversions (e.g., 42S, 32S/Sii, 20S, 28/48/49) use twos-complement only.


Hey, that sounds familiar! In the mid-to-late '80's, I maintained Fortran software running on Sperry mainframes. Sperry (which merged with Burroughs to become
Unisys during that period) was somewhat unorthodox in many respects, and they used 36-bit words with ones-complement integers. (Even then, twos-complement
was favored.) Memory dumps were rendered in octal, which fit the 36-bit words.

I worked with a Sperry 1100/60 in 1984-85 and did a little Fortran programming on it. At the time I was working as a (civilian) computer operator at an Air Force training base. We were in the process of converting all our applications from a Burroughs system (I believe it was a B3700) to run on the Sperry. I thought it was very funny that Sperry and Burroughs merged shortly after that project was complete. :-)

I didn't get my 16C until a few years later. By then I was working for another employer as a programmer/sysadmin on HP3000 minicomputers and IBM mainframes. The 3000 systems were stack-based machines and failing programs often produced octal stack dumps. The 16C was great for digging through them. It was useful for analyzing CICS hex dumps on the IBM, too.


Point taken. I had no idea, never owned one, am not a programmer.

The HP-16C is way too specialized for most people. I don't have actual figures, but it wouldn't surprise me to learn that the market share for this type of calculator were .001 of the share for all calculators.

That's also, by the way, why HP never created an airline pilot's calculator. Other companies make them and sell them to piloting students, usually through mail-order channels.

For the rest of us, a much simpler calculator that performs the very basic binary operations is sufficient -- and for that there are plenty of choices under $30 at Wal-Mart.

It doesn't make me happy to say these things. I had a 16C myself.



well I hear what you are saying, but why not serve that one in a thousand. And maybe its a little better than that anyway. Maybe its 1% of the market .....

Here's the deal, we get this continuous onslaught of greed, from greedy CEO's, who feel if they scoop up 95% of the money by satisfying 95% of the customers, that its enough, and that they dont care about the other 5%, because that would 'not offer enough return on investment'. And we hear that litany so often, that we think it normal that corporations tell their faithful customers to buzz off. Not only that, as we capitulate and try to think their way, then its "give 'em an inch and they take a mile" so they discontinue every calculator worth buying, until they aren't even serving 10% of their market anymore.

Why not serve the .001 specialty applications. I was very unimpressed with pilot's calculators I saw from the non-HP sources, and would've been delighted if there was one of high integrity and of logical thought processes. And isn't that what market penetration is all about? It is to be deeply entrenched across as wide a marketplace as possible so that all the world beats a path to your door.

So while your words are persuasive, you are just giving a fig-leaf to help this new generation of ultra-selfish MBA/CEO's something to cover up their naked greed, while they run off and buy another 20,000 square foot beach-front designer home.

I would say let HP serve the pilots, and let them serve the computer software people who want a 16C. When HP has already got a calculator engineering dep't, they can keep those people busy implementing a few 'low-popularity' models rather than do something so incredibly innovative such as sign off on coloring changes on a 12CP.

You gotta realize that once the drawings are done by an engineering group, then its 'over the wall' to the production people, and these models can be built for years and years, while the engineering group works on other things. We can understand that, I do NOT think HP's MBA management can understand that. Otherwise they'd keep building HP-15C, etc., using the same production line and the old tools and specifications.


So while your words are persuasive, you are just giving a fig-leaf to help this new generation of ultra-selfish MBA/CEO's something to cover up their naked greed, while they run off and buy another 20,000 square foot beach-front designer home.

Norm, I think you forgot to take your Valium this morning. That's OK -- we love you nonetheless.



aww c'mon, that was so perfectly true, that the sentence you took a 2nd look at, was written so perfect it was like a snippet of Mozart... every note and beat exactly where it was supposed to be.

Valium, what's that, is that like Lithium?

AS TO THE POINT, its completely true. These damn modern CEO's are so full of greed & selfishness that they dont even care about serving their markets....... it is an absolute embarassment to HP that they never served pilots with a couple of aviation calculator specimens. I'm sure if the MBA's would get out of the way, it would be possible to deliver some really beautiful work that would help all types of pilots from VFR to airline captains.

shame to HP calculator dep't, abandoning their principles and refusing to serve the world's needs. They try to sell us Walmart-Kinpo garbage instead.


Norm; There was flight planning and nav software for the 97 and 41, and of course the Concord used the 41. HP just didn't make a dedicated unit like the Navtrinic. You'ld like my navtronic. It's got a red LED.

Edited: 14 June 2003, 11:25 p.m.


looked under "navtronic"

and "navitronic"

just didn't find much. Nuthin' on eBay. Got any links ?? model numbers?

Hmmmmmm red led's in a cessna cockpit......
Sounds charming at first, however,
I could see a slide power switch with
3 brightness settings......

off, night, normal, bright.

If they didnt do that, it could be
hard to work with that under greatly
varying lighting conditions.


I have the Navtronic 1701 r, which has two National Semiconductor I.C.'s in it, among others. Joerg Worner has a 1701 t and yes; 1701 is the Starship Enterprises number. They were made by Specialized Electronics Corp. in Chicago. Mine is a nice solid unit with clicky keys. They refer to it as a "computer" and back then i guess it was. There is a pdf of the manual on Katie Wasserman's website at

Isn't she wonderful to do that for us?


Thanks for the compliment db!

There were 5 Navtronics that I know of:

The first was the model 16. Then came a series of 4:

1701 r - same as the 1701 with area navigation
1701 t - same as the 1701 with up/down timer and alarm
1701 tr - same with area navigation and timer/alarm

The marketing people got away with murder on this because as far as I can tell they use the same chip set. The area navigation works on my 1701 (plain) just the keys are not labeled and the chips are identically marked.

However the t and tr versions do have some extra stuff in there: a NS MM5368N oscillator chip, a 32Khz Xtal, a piezo element and a handful of passive components. Since these parts are still available and all the 1701's use the same circuit board it should be quite easy to upgrade a 1701 to a 1701tr for about $10. (I need to try that some day.)

Edited: 15 June 2003, 10:09 p.m.


got any pictures ?

Is it good enough to be useful to a modern day VFR pilot ?

Or have the rules changed enough to make it obsolete ?


here is a picture,

Hey, that does look like a nice little unit.

No B.S. just give me what I need.

So the main question is, are they good for modern usage ?

Were they popular? Do they show up on eBay ?


looks like "jeppesen techstar" is the only game in town.

I see they have a "jeppesen techstar pro" which sports a personal organizer, oooohhh !! wow! will having all my friends telephone numbers in there keep me from flying into a mountain ?

it looks like maybe even if 'techstar pro' was the newer one they discontinued it. Looks like 'jeppesen techstar' is the one pilots are buying.

plz correct if mistaken ...



I have the 41 Aviation Pac, as well as the Sporty's E6B, which is a purpose-built pilot's calculator with multi-line display. Ignoring the incredibly short battery life of the E6B, I found that the last thing you wanted to be doing while bouncing around in turbulence was diddling little buttons on a gizmo that didn't get everyday use the way our HP calcs do.

So I went back to the trusty Jeppesen CR-5, a shirt-pocket sized whiz-wheel that does everything you'd want, and has extremely simple one-handed data entry. And extremely long battery life, now that I reflect upon it.

But more than anything else, what has probably killed the pilot's calculator market is the hand-held or panel-mounted GPS. These things usually have an E6B data page that will tell you a lot more about winds aloft, fuel usage etc. than your calc would, with far less data entry because GS and TRK are fed into it continually. I have an Apollo Precedus, and it's amazing how it turned flying into something approaching a video game - no more being "temporarily uncertain of one's position".

With the whiz-wheel for backup, that's all you'd ever need.


--- Les []



Well, U are way ahead of me in the aviation department.

Sounds like people are none too enamored with the Jeppesen Techstar, although it is "FAA approved for written exams" and I bet U cant take your dash-mounted GPS to the written FAA exams ...

I took about 50 hrs of flying instruction which was probably 50% decent instruction and 50% joyride.

While enjoying it immensely, I came to realize that the #1 mandatory ingredient for successful flight is NOT knowing the exam material and NOT aviation fuel and NOT the horizontal component of lift........

Nope, #1 mandatory ingredient for flight is money, and measured only by the wheelbarrow full, and lots of 'em.
So I have reattached the tie-down ropes for good, until I figure out how to be a better swindler and rip off some unsuspecting working class, like all the MBA's who have got their big stack. Soon as I do, its back to the runway.


In the same boat here, Norm. It was all very well when I was young and single, but now with two kids and the decline of the IT business, I've had my wings clipped as well.

But you've obviously discovered what a lot of aeronautical engineers long suspected: Bernoulli was completely wrong, and what causes lift is *money*.

I hope you are able to get back to it - there's *nothing* else in the world (that you can do with your clothes on) that's as much fun!


--- Les []


The 16C really is a product without a proper place in the world. It was introduced at the end of an era when programmers did a lot of bench-checking of assembly and other low-level code, particularly for mainframes, where they couldn't get actual machine time for debugging.

These days, we code in higher-level languages, and we typically code, compile and debug directly on the target platform. The types of calculations the 16C performs are often built-in to the debuggers.

And of course, the floating-point representation used in the 16C was unique to HP minis. The incorporation in the manual of a routine to covert that to and from the now near-ubiquitous IEEE-754 format is a stop-gap solution and not much more.

I have a 16C that I picked up new in 85 or so, but I rarely use it for anything computer-related, other than those occasional hex-decimal conversions. I occasionally wave it around in networking classes when teaching subnet masks, but in practice, I work those out in my head.

Still, it's an elegant toy; I might be able to use it if my son asks me to explain boolean logic and De Morgan's theorem, but that's about it.


--- Les []


Yeah, I have to agree...

When I moved out here (SF bay area) to start work as a programmer in the early 80s, the 16C was a godsend. When HP quit making them, I panicked, wondering what I'd do if mine died.

I prowled the streets of San Francisco, where I found dozens of tiny import electronics shops run by people with a tenuous grasp of English. You could often find older HP calcs there. Over a summer I picked up 3 additional units.

So now I have four. They all work perfectly. And I can't remember the last time I used one for real. Sigh.

If anyone here wants one for a collection, let me know.


Hi, Les Bell;

I reluctantly have to face it and completely agree with you. When I got my NIB HP16C in the mid 80's I used it to test almost every logic design before going to PCB. If programming was needed, no matter: let's exercise the brain.

It definitely replaced protoboard for me when logic design was the issue. After setling logic design, electronic design demanded actual HW.

Sad, instead true: I still use mine because I still design digital stuff. Mostly for my own.


Luiz C. Vieira - Brazil

Edited: 13 June 2003, 1:43 a.m.


Sorry, but I cannot more strongly disagree with you! Yes,
the majority of programmers these days are operating in
the nose-bleed echelons of high-level languages, and have
no use for hex/bin/oct, but the absolute number of people
operating in low-level regions has probably not decreased,
nor has their importance to development of new products.
I'm an embedded-systems engineer, and most of what I work
on is lucky to have an indicator LED, let alone an actual
display, and debugging my code involves constant use of
my trusty HP-16c. And DON'T tell me I should be using
some piece-of-crap calc-tool built in to the all-too-fancy
Windoze-running 'scope I am reduced to using these days.

No, most programmers may have turned their backs on the
"Bad old days" of manual radix conversions, but there are
still lots of programmers who need them, and the HP-16c is
the only game in town.


Don't worry, Grant, we'll work something out!

BTW, folks, my spare 16Cs are now gone...


I just bid. There's no need for anyone else to try and outbid me, as I bid really high, and there's no hope for any of you - Just let it go, and hope for another one soon.

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