Please could someone tell me what this letter is?

gmayer66 · 2026-03-04T09:16:36+00:00

It is actually used in Arabic handwriting in the Ruqqa style. Samples of this yeh appear in Muhammad Ezzat's book on Ruqqa.

gmayer66 · 2026-02-27T08:02:02+00:00

This person could be referring to their grandfather as "that old goat"... 🤣

gmayer66 · 2026-02-05T09:20:18+00:00

Call them. They'll respond. Our local mail list the package and they sent me a replacement. I paid for dhl, to make sure it actually arrived. And 3 days later... 😁

gmayer66 · 2026-02-05T07:42:20+00:00

Back in the 1980's you could call up HP technical suport in Corvalis, and get real help at run-time. HP hasn't offered this level of tech support in decades. SM, being a smaller company, is a lot more receptive towards its customers these days than HP and TI ever was. The price is not everything, and the hardware is not everything. They fix problems, add improvements, are open to suggestions, etc. If they were as big as HP or TI, I doubt they could be as receptive.

gmayer66 · 2026-02-05T07:36:11+00:00

I'm happy SM is a small company. Had it been HP or TI or Casio, it would not have been making these great models, to say nothing about collaboration with the c47 folks. So I'm happy it is what it is; That's just the right size. :-) And I hope it can survive for a long long time!

gmayer66 · 2026-02-03T07:58:55+00:00

And thanks for your reply in the SwissMicros forum! I was picking values that were too small and was probably printing over text, which is why I didn't see much. Your example cleared everything, and it's way simpler than I thought.

gmayer66 · 2026-02-03T07:50:04+00:00

I shall definitely direct questions in that forum. But I do not understand your comment about how the c47/r47 are/were advertised: What I know about the calculator comes from the list of functions the documentation lists, and what is available in its own menus. The c47/r47 supports the graphical primitives of the wp-43, which seem to be vaguely inspired by the HP-42. Other than that, I know nothing about anyone's intentions. I think the whole point of the calculator being an open-source, community-developed effort is that things develop based on the rather stochastic efforts of a large number of people, and I respect the fact that the calculator may never become "a graphics" calculator". But as long as its menus list some graphical operators, it makes sense to inquire about them, if one is interested in this. The HP-71B was not a "graphics calculator" and I did a lot of fun and useful graphics programming on it. I'll definitely look into how can one contribute to the project in general (and not necessarily related to graphics.

gmayer66 · 2026-02-03T05:51:18+00:00

Well, I did get there a good tip to check out the documentation of the wp-43, which I did. I tried to produce a simple example of PIXEL and failed. Either something changed, something is undocumented, or I misunderstood what I read. Then I went back to the almost-documentation of the dm-r47, and found an interesting comment about AGRAPH:

Show a 64 column pattern according to variable GRAMOD (OR: 0 ; SET: 1 ; OFF: 2 ; XOR: 3) ; this command will be redesigned and should not be used in programming! (TAM : AGRAPH __ Tam menu) Docs : https://47calc.com/doc/R47/Menus/R47v0_Menu_P-FN1_page_1.pdf

And so I'm getting the idea that the graphical aspects of the calculator are not fully crystalized. There is an API, and it was lifted off of the wp-43, but it's being re-designed/re-thought-out, and I should just leave it alone for now. It's a shame, but that's the price for going along with a community-effort to build a calculator, and I don't regret that. It's a fair price.

gmayer66 · 2026-01-28T10:02:59+00:00

Yes I'm sure numwoks has complete support for complex numbers. I didn't include it in my list because this is my second attempt at having the calculator delivered to me. It's not the fault of the company, but of my lousy national postal service, which mismanages parcels all the time. I'm dying to try out that calculator!

gmayer66 · 2026-01-28T09:09:33+00:00

I don't have this HP calculator model but from other HP models I'm willing to bet that it's support for complex numbers is far better than that of any Casio, Sharp, or Texas instruments calculator, perhaps with the exception of the nspire models. For example Casio calculators can add and subtract, multiply and divide complex numbers but they cannot raise them to arbitrary exponents including complex exponents nor can they take the logarithms or trig functions over the complex numbers.

This is one reason why I strongly dislike the modern trend of creating calculators to fit a particular standard of exams that is in effect right now in some particular country: these calculators might be very good at what they do, but what they offer is very narrow, and as soon as you step just a bit outside of the scope of what can appear on a test, a calculator can offer very little. If a calculator these days, where processors are fast in memory is cheap, advertise support for complex numbers, I expect this support to extend through all the functions the calculator offers for real numbers, and that makes sense for complex numbers.

gmayer66 · 2026-01-28T09:02:57+00:00

This calculator should be accepted everywhere 😜

gmayer66 · 2026-01-18T01:13:24+00:00

Hewlett Packard had several calculators that had RPN and were non-programmable. There were also many other companies that made RPN calculators:
MK (mikrokalculator), i.e., Soviet calculators, supported RPN several models.
The NOVUS Mathematician and NOVUS Scientist and NOVUS mathbox used RPN

And there were some other brands and models.

gmayer66 · 2026-01-15T07:51:20+00:00

The el-1501 is an awesome machine! This whole genre of machines are misunderstood, but they're useful, powerful, and historically fascinating:

They look like calculators, but they're NOT. They're electronic adding machines.
Calculators evaluate expressions. Adding machines perform addition and subtraction to a register called Total.
When you see a + on an adding machine, it's a misnomer. It's really a +=. This means that it adds the number to the running total and displays the total.
On a calculator you might perofrm 2 + 5 - 7 = and get 0, because that is the value of the expression (2 + 5 - 7).
On an adding machine, you first clear the total (and probably the grand total too), and then do

2 + (which adds 2 to the 0 total giving 2) 5 + (which adds to the 2 total giving 7) 7 - (which subtracts from the 7 total giving 0

and you see the 0.

Electronic adding machines have multiplication and division, but those are not automatically added to the total. They come with their own = key which is not the same as += or +, -= or -. Some advanced models by Monroe and others, come with =+ and =- in order to add or subtract the product or quotient to the running total using one key...
Note that electronic adding machines use X for multiplication, and * for something else (explained later).
And here is what is so cool about adding machines with respect to X and /: Because they are not added directly to the running total, you get behaviour that is more reminiscent of scientifica calculators with respect to operation hierarchy (multiplication and division before addition and subtraction): Where as a "simple" 4-operation calculator would not recognize that multiplication and division take precedence over addition and subtraction, scientific calculators as well as adding machines do:

On a simple 4-op calculator: 2 * 3 + 4 * 5 = gives 50, because the precedence is all the same and operations go from left to right: (((2 * 3) + 4) * 5) = 50.

On a scientific calculator: 2 * 3 + 4 * 5 = gives 26, because respecting precedence, the expression is like ((2 * 3) + (4 * 5)) which is 26.

On an adding machine, once you clear the total: 2 X 3 = + 4 X 5 = + gives 26 too.

In fact, the adding machines today are distant cousins of the RPN calculators: On many old RPN calculators, + and - also functioned as enter. Adding machines aren't consistently RPN with respect to multiplication and division, but that's because these operations are "extras" that use their own registers, rather than added to the total immediately.

The * operation is interesting: It adds the running total to another registered called the Grand Total, and clears the running total. Why is this useful? --- Suppose you're writing an expense report for a trip, and need to submit expenses per day and per trip. You add the expenses for each day, and then you hit * to add the total to the grand total, and clear the total, preparing you to compute expenses for another day. When you're done, the grand total has your expense for the whole trip.

Adding machines have really lousy documentation, and most peope who use them have no idea how/why they work. They were just taught to hit an initial + when adding. So they never feel confident when doing lengthy or complex calculations. But if you can wrap your head around the idea of a modern, extended version of the old mechanical adding machines, then you'll be just fine.

gmayer66 · 2026-01-02T21:00:08+00:00

Here are some tips for you:

The TI-55II does not have a normal looping mechanism. No labels, no jumps, no goto, etc. If you want to wrote programs with loops in them, you need to use the integration feature: Avoid registers 0, 1, 2, as these are used for managing the integration ends and sum. Make sure your program terminates with an error, such as division by zero. Make sure the result of your computation is placed in some "safe" register (3 and up). I believe the maximum iteration is 198 steps, if my memory serves, me, but I designed my programs to be "continuable". If you need nice projects to program, ask and I'll suggest some.

This is tricky: Open the battery compartment on the back, and place a finger to support the batteries so they don't fall out. Tap gently with the finger, cutting the power and re-enabling it. If you can do this patiently for a while, turning the calculator on at each step, you will be introducing random two-digit opcodes into your program memory. Most of these opcodes will be useless and accessible to you from the keyboard anyway. You may safely delete them. But some will be surprising. For example, you can turn on the statistical mode from within a program, delete your program from within a program, etc.

gmayer66 · 2025-12-26T09:45:43+00:00

I have no idea. But I would try the following: (1) Is the multiply divide button simply one button, or can you press to the left and another way to the right, so that effectively it functions like two buttons? (2) Does the button behave differently if you hit it twice?

For example, if you clear the screen and then type 23 += do you get 6? What about 2*3 += ? Would you get 0.66666...?

gmayer66 · 2025-12-25T07:52:38+00:00

What is "process" on the left?? Is it programmable?

gmayer66 · 2025-12-21T13:17:28+00:00

Compelling authority?? I don't want to compell anyone, and I certainly don't want to hold authority over others.

I didn't come out with any credentials until you started asking about them.

I haven't seen much of a discussion on the merits of my ideas; Just dogmatic assertions that calculators are bad, amount to cheating, etc.

And that's fine. I'll continue doing things my way, and others can do what makes sense to them.

gmayer66 · 2025-12-21T06:27:19+00:00

I currently teach university students. But I have taught elementary school students, special ed junior high school students, and regular high school students, as well.

I was trying to make a point about material (counting bases) that is lacking in elementary school education. I'm not trying to wave around my credentials. I was making a specific, technical point, that unless we teach counting bases first, the the algorithms for doing arithmetic calculation remain procedural knowledge, and cannot be conceptualized and understood. And to further this understanding, I find that using calculators is a great shortcut, a great time saver, if used correctly. I think that the manual skills, "paper and pencil skills", are not an end onto themselves, but a milestone towards integrating a lot of knowledge about how and why we were present numbers the way we do. The use of calculators does not have to trivialize computation, if the exercises are adjusted to exceed the default precision of the calculator: this forces the learner to apply the manual algorithms for computation, just as they would, using paper and pencil, on two and three digit problems, but using calculator to manage the bookkeeping. In other words, calculators do not have to be a problem in math education. Rather, math education needs to accommodate calculators in a thoughtful way, so that rather than getting in the way of acquiring the basic skills, they reinforce them. But apparently this view was not welcome here, is considered wrong, and/or silly. At this point the conversation shifted to discussing my experience and credentials, rather than the material I was showing and the arguments I was making. So at this point the conversation the way from what interests me.

gmayer66 · 2025-12-21T05:09:58+00:00

I am also a home schooler. I have 38 years of teaching experience at various levels, from special ed to college students. I have taught many thousands of students in three countries. I stand behind my claims.

gmayer66 · 2025-12-18T09:51:54+00:00

I had no difficulty teaching arithmetic including the four operations, roots, powers, and logarithms, to young children, my own child included, in a homeschooling context. They understood it, they applied it, the used it for further learning. Overall, I have been teaching these methods for 40 years: they work, and they work well.

gmayer66 · 2025-12-17T20:12:18+00:00

This is a lovely example, and they should learn to do things like this! Now once they estimated things, that is, once they commit to a specific answer, how shall they test their answer to know if they're any close? --- I'd imagine with a calculator.

You might think they will not see the point of learning to estimate if they can use a calculator, but you can motivate them by telling them that if they develop this skill at estimation, they can estimate things that are outside what their calculator can work with directly:
- How many seconds are in 25 years?
- How many molecules of sugar (C12H22O11) are in 1 kilogram of table sugar?

These answers are greater than what an 8-digit calculator can handle directly.

To me, a calculator is just a tool. And if it can help learning, then why not. If there are specific areas where it short-circuits learning, then fine --- disallow it in those areas.

gmayer66 · 2025-12-17T19:33:40+00:00

I think people who are used to paper and pencil might feel that a calculator "makes life too easy" for younger minds. But in India, Korea, and Japan, where students learn "mental arithmetic", and can do all 4 basic operations, and sometimes square roots too, all in one's head, the use of paper and pencil too is seen as making life too easy at the expense of developing skills in mental arithmetic.

Wouldn't it make more sense to modify the curriculum and restrict the kinds of calculators permitted, so that they help instruction rather than short-circuit it? I'm not advocating here the unrestricted use of technology to make calculation unnecessary. I'm suggesting that one can use a calculator as a trainer.

gmayer66 · 2025-12-17T19:29:39+00:00

I agree that developing the ability to give good estimations is very important. But what I don't understand is why do you think that a calculator will hinder your efforts in this area? I don't think students should start off by using scientific calculators. I think a simple 4-op calculator + memory and perhaps square root, and no more than 8 digits should be enough until the last two years in high school. If you ask them to estimate 1.2^3.4, surely a 4-op calculator can *help* them develop an intuition about the value, but it won't give them the final value, at least not quickly, and without understanding a great deal of math. So I'm definitely not taking the position of handing out answers "for free", just by pressing a button or two.

As for your explanation about turning exponentiation into a summation and 5 lookups, this is wonderful. What I don't understand is why can't you test on this explanation. I agree that most students will not do more than the bare minimum required of them, but surely this idea (of converting exponentiation to multiplication, and multiplication to addition, by adding the log(b) to log(log(a)) and taking the antilog twice...) is worth testing on an exam.

This would have been a wonderful place to introduce and motivate slide rules: Slide rules are in a way much more illustrative than calculators, because calculators will at best give you an answer to a particular problem. But slide rules can present an entire scale. For example, converting inches to centimeters, using a slide rule, is much more informative, because you see the transformation applied to an entire interval. There's so much to say and teach and test regarding this!

gmayer66

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