My first programable HP



#20

Sometime tn the 1980's I purchased a Sharp el5813 to run a frequently used equation in our lab. It was a nice little shirt pocket calculator but had only a 30 step memory so one had to be creative to program it. Several years later I walked into an electronics store and saw a handsome calculator in the display case, it looked good, felt good and the key feedback was positive. The clerk warned me that it used " reverse polish notation" which I thought was a joke/sales ploy to steer me to another brand so I bought it. Thats how I acquired my first HP, the 11C. Both calculators are still alive and well today.


"


#21

I fondly remember the 5813. Mine got stolen while I was at high school, but I bought one 25 years later. It's a nice little machine, that got me into programming. The keyboard is excellent, as is the display.

#22

Reminds me of my el-512 I had in high school (a whopping 127 program steps). A year late I had the el-5100s, and THEN finally an HP-11c. All great devices in my mind. I hadn't seen the el5813 before.


#23

When I was in high school my Dad showed me repeated triels to close in on a solution. With my HP-65 I could do repeated trials, and with the magnetic tape I could resume easily. I was working with thermistors and had data on them. I could match a curve using Ln and 2 constants. I matched curves in many EE books. I was not limited to polynomials or recursion. My boss ran a glider club and asked me to compute a number of distances between geographic coordinates which was easy. A co-worker asked me for the formula for active filters, I said I don't know, it's on tape.


#24

Tape? Tape??? We don' need no steenkin' tape! We use cards!

Well, OK, we might use tape on an 82161A, or a Series 80, but not on an HP-65. :-)

I haven't lost my mind, I've got it backed up on tape around here somewhere...

#25

For what it is worth, when I was in high school my first main calculator was the Casio fx-7000G, which was the first graphing calculator from my understanding. Now, ~18 years later, I still have and use that calculator.

However, when I was in college I acquired an HP 48SX and liked it for its overwhelming abilities, as well as its expandability. Not only do I still have the 48SX and many of its cards, but just today I was remarking to a friend that I felt the 48SX was more akin to a computer than a calculator.

As it happens I have recently discovered the beauty and functionality of the HP 15C and plan on making one I just purchased as my primary working calculator. While I am new with the unit, I am impressed with its design, feel, and programming abilities. In fact, I get the feeling I am going to like the 15C very much! :-)

As a curious side note, I had the 48SX/15C discussion with my friend as he was on his way out to buy a lovely new HP 50g!

Always...


#26

Quote:
I still have the 48SX and many of its cards...

...I am going to like the 15C very much!


Cards for the 48SX??? Not magnetic...do you mean the solid state units?

My 48SX is almost 20 years old, my 67 is 31, and my 41CX is 24. I also added the 48GX, 49g+, and 50g. I am very happy with the 50g. The 48SX and 48GX are terribly slow and had fuzzy displays from the start.

As far as true pocket models, IMHO the 15C is one of the best. Still, it falls far short of its replacement, the 20-year-old HP42S. I used the 15C for 11 years at work and I love the style, even though the "landscape" keyboard is actually much less effective for hand held use than the traditional calculator layout. I guess that's why it hasn't been repeated.

The 42S is an absolutely astonishing machine. Compared to the 15C, it is much faster and more precise, has many more functions, and with its two-line alphanumeric display and menu system it is far easier to use. Functions are obvious on the 42S that are hidden or obscured on the 15C. The 42S has IR printer output. The traditional keyboard layout of the 42S is better. The 42S has an interesting machine language debugger function. Both units are essentialy the same size and weight.

One area where the 42S fails is appearance. I don't know what HP was thinking when it selected the color schemes for most of its calculators for the past 20 years. It appears that some west-coast art-school crowd was consulted. Who else would choose the fecal-matter-brown and orange idiocy that was used for this series of calculators?

I would also have loved to see an updated model that had some of the clock/calendar and financial functions of it brother, the HP17BII.

So...try a HP42S. You'll still like and respect the 15C, but you'll carry and use the 42S.

Mike


#27

Hi, Mike --

We've almost reached the one-year anniversary of a very similar discussion:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=110776#110776

Some comments about the "repeat":

Quote:
Functions are obvious on the 42S that are hidden or obscured on the 15C.

Once again, I don't follow. Every function on the HP-15C is, by necessity, listed plainly on the keyboard face or "indexed" on the back plate. By contrast, many of the HP-42S' numerous functions, again by necessity, are buried within menus, or are available only through the function catalog, if the user does not wish to spell it out, letter by letter.

Quote:
I don't know what HP was thinking when it selected the color schemes for most of its calculators for the past 20 years. It appears that some west-coast art-school crowd was consulted. Who else would choose the fecal-matter-brown and orange idiocy that was used for this series of calculators?

Your verbatim statement from a year ago:

Quote:
That terribly ugly, low contrast, fecal brown and orange color scheme. Some gang of new-age left-coast artsy nitwits at HP really messed up *all* HP calculator color schemes after the mid-1980s (but that really started with that unappealing HP-41C in 1979).

Apparently, my response from last year was totally unconvincing. I see yellow, not orange, as the HP-42S shift key color on each of the three HP-42S calc's I use. I find the dark brown to be quite inoffensive -- as much dark gray as brown, with very little yellow or red in the mix. You seem to have some vendetta against the USA's West Coast, artists, and (ahem) "residue"....

Now, for a real example of low-constrast, hard-to-see "designer" colors, check out the original blue-blue-red HP-49G.

Quote:
I used the 15C for 11 years at work and I love the style, even though the "landscape" keyboard is actually much less effective for hand held use than the traditional calculator layout. I guess that's why it hasn't been repeated.

I agree completely with you there. The Voyager series was designed in the early 1980's for desktop/tabletop users, not for field users. Its landscape layout made perfect sense with most users not having a PC keyboard tray in the way. That began to change in the late 1980's. I now use a 32SII and 42S over the 15C at work, for several reasons.

-- KS


Edited: 14 Mar 2008, 2:00 a.m.


#28

Quote:
Its landscape layout made perfect sense with most users not having a PC keyboard tray in the way.
I find it more convenient to have a landscape calculator in front of the keyboard instead of a portrait calculator next to it. Of course, ymmv, but to me it is one of two reasons to still have a TI-66 in use.

(just wanted to state a different opinion about that ;-)

#29

Quote:

Cards for the 48SX??? Not magnetic...do you mean the solid state units?


I do freely admit that I am not an HP expert in any way, yet my 48SX had these rectangular software cards that could be put into the back expandable ports of the calculator. Looking at the pacs I do not see the word card on them, thus if I was in error I do apologize. Would it be better to call them rectangular software disks (they look like a rectangular version of a 3.5" floppy disk)?

I will be sure to keep the HP 42S in mind, however, my use of the 15C is for my office and for the classroom, not necessarily for the field. Yet if I do get into field work that requires a calculator I will look back into your suggestion. Thanks!

I am curious, though. I have never heard someone refer to the 15C as not as accurate as some other HP calculators. For myself I hope to use the 15C in my graduate geology classes, as well as for the classes I teach. Would the 15C not be suited to these uses, especially since I do not see myself writing many (if any) complex programs? I may, perhaps, write some simple ones for everyday use...

Thanks!

Edited: 14 Mar 2008, 8:23 a.m.


#30

The 15C is a Voyager series calculator with fewer display digits (and less internal precision) than the 42S and other models of the Pioneer series.

You can see the results of a test computation here:
http://www.rskey.org/~mwsebastian/miscprj/models.htm

The exact answer is 9.
The 15C result is 9.000417403 (+0.0046%)
The 42S result is 8.99999864267 (-0.000015%).
Thus, the 15C error for this calculation is 300 times greater than the 42S.

Edited: 14 Mar 2008, 10:58 a.m.


#31

That's an excellent example that shows the difference in precision *and* accuracy between results from the 15C and the 42S.

"Precision" tells us how many significant figures an answer is given, while "accuracy" tells us how close the answer is to the true value. A result from a calculation that should be Pi could be shown on machine A as 3.141599999, and on machine B as 3.141592654. Machine A and machine B have the same precision (10 significant digits), but machine B has much better accuracy than machine A.

AFAIK, all Saturn (real or emulated) based scientific calculators (such as the 42S, 32S, 32SII, 48/49/50 series, and even the lowly 20S) performing the same calculation will generate answers of identical (and excellent) accuracy and precision that are much better than those obtained from pre-Saturn calcs like the 15C.

Not having one, I don't know if the recent Kinpo units such as the 33S and 35S will generate the same numbers as the Saturn-based units.

The 30E/C-series (Spice) and 10C-series (Voyager) have the same *precision* as the earlier Classic and Woodstock units. But the firmware algorithms in Spice and Voyager models produce much better *accuracy* than those of most of the earlier models. (The 67 and the 19C/29C have the better accuracy algorithms that appeared in later models.) For example, the same calculation performed on a 34C and a 15C will produce identical results. Likewise, the same calculation performed on a 65 and a 25C will produce identical results, but they will be of lower accuracy than those from the 34C and 15C.

FWIW, a 2499-iteration loop of the old classic "Savage" benchmark will execute *significantly* faster on a 25C compared to the later 34C, but the accuracy of the 34C will be better. Apparently the better accuracy of the 34C is obtained with a trade-off in speed.

Thus, the old Classic and Woodstock machines are lowest in precision and accuracy ratings. The Spice and Voyager machines have the same precision as the earlier models, but better accuracy in general. The Pioneers and other Saturn-based units have both better precision and better accuracy than any earlier models.

These differences will likely be of significance only in long or repetitive or iterative calculations. As one who made the transition from slide rules to calculators in my professional life 36 years ago, it still seems a little unnatural to be worrying about all those digits way out on the right side of the decimal point.

Mike

Edited: 14 Mar 2008, 2:28 p.m. after one or more responses were posted


#32

Quote:
For example, the same calculation performed on a 34C and a 15C will produce identical results. Likewise, the same calculation performed on a 67 and a 29C will produce identical results, but they will be of lower accuracy than those from the 34C and 15C.

For what it's worth, on the aforementioned problem, my 19C (29C with a printer) produces the same result as the 15C. Same precision, and same (in)accuracy.

Stefan


#33

Yes, I made an error citing the 29C and 67 which I subsequently corrected (thank goodness for the edit function!). The 67 and 19C/29C appear to use the improved algorithms that were used in later models. In contrast, the 25 and 25C definitely use the earlier algorithms.

Mike

#34

Hi, Ken --

Quote:
The exact answer is 9. The 15C result is 9.000417403 (+0.0046%) The 42S result is 8.99999864267 (-0.000015%). Thus, the 15C error for this calculation is 300 times greater than the 42S.

The forensic test (as its name implies) was probably devised as an indicator of a calculator's methods and algorithms. Some people have seemed to view this test -- I'm not saying that you have -- as a definitive metric of a calcuator's accuracy.

Valentin had discussed the issue several years ago:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv014.cgi?read=69026

and I posted my own take on the matter a while ago:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=113143#113143

You referred to the forensic as "this calculation", but really, it's six calculations (plus six more in degrees mode, for the internal
deg<->rad conversions).

The lowly HP-30S gives a perfect answer, but that's due largely to its taking the liberty of rounding extremely-near integers. (The 80-bit floating-point math is the other reason.)

More about that:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv016.cgi?read=103499#103499

-- KS


Edited: 16 Mar 2008, 3:43 a.m.

#35

Quote:
The 15C is a Voyager series calculator with fewer display digits (and less internal precision) than the 42S and other models of the Pioneer series.

You can see the results of a test computation here:
http://www.rskey.org/~mwsebastian/miscprj/models.htm

The exact answer is 9.
The 15C result is 9.000417403 (+0.0046%)
The 42S result is 8.99999864267 (-0.000015%).
Thus, the 15C error for this calculation is 300 times greater than the 42S.



Hello!

I must say that this is quite interesting, and I was not looking at the issue along these lines. However, and please I do not mean this in a poor sense in any way, I do not think that, for my intended use of the 15C (i.e. taking Ph.D. science classes, and teaching science at a community college), a small error in the 1,000th+ decimal place will matter much. This is especially true since my degree area, while using mathematics as a tool as all scientific endeavors do, is not pure/applied mathematics, physics, or engineering. As such I want to be accurate, to be sure, but it appears that the 15C will be perfectly sufficient.

Thoughts?

Always...


#36

Santeh --

Here's my response to your requests for guidance:

You should consider getting an HP-32SII, as it combines the ease of use and clear display of the HP-15C, with the accuracy and speed of the HP-42S. It also adds functionality for equations and fractions. However, it lacks some advanced functionality of the latter two models, such as matrix calculations and thorough, easy-to-use complex-number support.

-- KS


#37

Quote:
Santeh --

Here's my response to your requests for guidance:

You should consider getting an HP-32SII, as it combines the ease of use and clear display of the HP-15C, with the accuracy and speed of the HP-42S. It also adds functionality for equations and fractions. However, it lacks some advanced functionality of the latter two models, such as matrix calculations and thorough, easy-to-use complex-number support.

-- KS



Hello!

Thank you! I will take a look at the HP 32SII! I appreciate the tip.

Respectfully...

#38

Started with the HP 25 in 1978, then the 25C followed by a 67 and 97 in the lab. For graduate studies turned to the newly arrived HP41 followed by 41CX and a spare in 1990, halfnut 41CX.

Picked up a 48G and 48G+ but they just sit as I still alternate the HP67 and HP41CX through the cockpit.

Still have all of them!!

Still have the wand, HPIL module, disc drive, plotter, stat, PPC, 2 X extended memory, HPIL printer, infared printer as well as 3 card readers. Might go back to school so I want my familiar friends with me!!

Cheers Geoff



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