HP calculators for everyday engineering



#24

Greetings, Ladies and Gents...

I am new on this forum, but not to the HP RPN calculators.

My addiction started with the HP 25 in 1976.

Became the proud owner of an HP76 in 1978 and I use it ever since, ... less the card reader in the past 10 some years.
I also own and use an HP 28S and a couple of 42S models and a 50g calculator.

... I hate the 50g as much as I love the 67, because of the insane manual the 50g came with. After many frustrating attempts I am completely turned off from even trying to write a program for the 50g!

My 67 was my pride and joy. This calculator should be called a mile stone in simplicity and excellence!
I wrote most programs in only seconds.. (and I have written countless programs for mechanical engineering applications) unfortunately I can't save anything due to the condition of the card reader's rubber wheel.

Question: Is there anybody out there who figured out how to put a decent size flash memory chip in the space of the 67's card reader?
... I dream about that solution.

I dream about HP coming out with a rugged calculator, identical to the 67's keyboard and the same simple program functions, but with a 2 or 4 line LCD display and a 4+ GB memory!!!

I would be wiling to pay for it $700 or more for it, like I paid for the 67 originally!!! (HP designers!!! Are you listening???)

My second question: Any proven ideas on adding a larger memory to the 42S models?

All suggestions and help will be greatly appreciated.

Stephen I. Molnar


#25

Extending the memory of the 67 wouldn't be practical since the processor wouldn't be able to address it.

Extending the 42S to 32kb is quite doable but questionable since all programs have to be keyed in by hand, a daunting task for that much memory. Since there is no way to back it up, hours and hours of manual labor would be gone in the blink of an eye without good batteries in place. If you're into such masochistic practices, here's how:
Extending the 42S to 32kb

Perhaps the best solution would be to look at some of the calculator emulators that run on PC's. Program storage isn't an issue with most of those implementations as they store to the PC's disk.

Edited: 28 Jan 2008, 8:01 p.m.


#26

Actually extending the 67 and 97 to support more memory (programs and data registers) isn't that hard, once you've reverse-engineered the microcode, which I've done in the process of trying to get them working correctly for the next release of Nonpareil. Lately Jacques Laporte has helped a lot with reverse-engineering how the card reader control chip works.

The portions of the code that need to change are:

  1. The user program in the standard 67 is stored in reverse order from the register at 0x2f down to 0x10. The easiest way to increase this is to move the start of the program up to a higher address. For instance, to double the program memory to 448 steps, move the start to 0x4f.
  2. The secondary registers are from 0x20 through 0x29. Relocate these upward to e.g. 0x50 through 0x59.
  3. Add another 32 registers only accessible indirectly at 0x5a through 0x79. These would be accessible by indirect addresses 26-56.
  4. The PC, return stack, display mode, trig mode, user flags, and various scratchpad space are from 0x2a to 0x2f. Relocate these to 0x7a through 0x7f. There are references to these scattered everywhere in the ROMs.
  5. The P<>S routine and the routines that handle indirect register addressing need to change for the different base of secondary registers and to handle the additional indirect registers.
  6. The PRINT REG instruction would need to be changed for the additional indirect registers.
  7. The biggest changes would be the card reader routines, to handle programs or data that occupy more than two card sides. Such cards written on an extended 67/97 would not be compatible with the standard 67/97 or the 41C.

And probably a few other changes I've overlooked.

It appears that the maximum contiguous RAM that can be addressed is 0x00 through 0x8f, because the card reader chip responds to two addresses in 0x9x, and the PICK (printer/keyboard) chip responds to one at 0xff. Possibly registers could also be added from 0xa0 to 0xef.

From a hardware point of view, in the 67 this would require replacing all four of the 8-pin RAM/ROM chips with a daughterboard with a microcontroller to provide the altered ROM contents and expanded RAM. A CD4066 transmission gate or the like would be inserted in the ISA line to the ROM/Anode driver chip to allow the microcontroller to replace its ROM contents while still allowing it to capture the display data from the ISA line.

I wonder how many people would buy a 67/97 upgrade kit?


#27

Quote:
I wonder how many people would buy a 67/97 upgrade kit?

Personally, I'd be more interested in a USB connection to my 42S. Keycodes and battery eating LED's might be retro but I get more work done with LCD's and batteries that last for a year or more.

PS: If you did the 67/97 extensions, a good source of mag cards would need to be developed as well.

Edited: 28 Jan 2008, 8:50 p.m.


#28

... Actually I had the mini USB port idea in my mind for the 42S, but somehow I missed it from my thread.

Gentlemen, please understand, it must be the frustration with my 50g that brought out this nostalgic feeling for the simple programming of the 67 from me.

... I actually bought all the gizmos with that calculator in 78 and by the time the dust settled the bill was close to $ 800 Cdn. for my calculator. (Security cradle etc...)
That was a lot of money in 78, however the speed and simplicity of the 67 paid for itself in a very short time.

...By the way, HP must have sold quite a few thousand 67 and 97 models. That was way back, when the air was clean and something else was dirty (Hmmm) ... and well before world peace boke out!

What I am dreaming about is a small pocket calculator that you could carry anywhere and have the right answers in a split second even on the shop floor without a computer.
The 67 did that... given a few known variables in a second or two you had the solution for the unknown blinking at you.

... Now imagine a very simple scientific calculator where you don't have to load the magnetic cards, but 100s of equations are stored on a removable flash memory card...

... This is what I was dreaming about when I bought the 50g...
But that is a completely different problem!

Anyway, thanks for the tips.

Stephen


#29

Hi, Stephen,

did you dream of anything like this?

An equation library is featured under E.LIB. Overall, its Pioneer-size, whith the same LCD like a 39/40. What you cannot see, of course, is the MiniUSB ;)

Edited: 29 Jan 2008, 7:37 a.m.


#30

Walter,

The image of this sexy calculator makes me think of when Michael Angelo finished the masterpiece sculpture of David and said "Speak!" (if I remember the Italian tour guide from my childhood, Angelo also struck the sculpture in frustration because it did not speak). In this case, I want to say "Compute!"

Namir


#31

Quote:
[...] Michael Angelo [...]

;-) That's a good one! ;-)

#32

Quote:
Michael Angelo finished the masterpiece sculpture of David and said "Speak!" (if I remember the Italian tour guide from my childhood, Angelo also struck the sculpture in frustration because it did not speak).

Apart from Michael Angelo ;-) I think that the subject was Moses and not David.
But we got the picture...

Greetings,
Massimo


#33

Quote:
I think that the subject was Moses and not David.

Moses...Exactly!

But you're from Italy - that got to be easy for you! I guess you're standing right in front of that thing and speaking to the tour guide, right?!?


#34

Quote:
But you're from Italy - that got to be easy for you! I guess you're standing right in front of that thing and speaking to the tour guide, right?!?

Unfortunately not. I'm from Rome but I do live in Milan.
Oh well! I can go out and take a look at Leonardo's Last Supper!
Where's the queue?

Greetings,
Massimo


#35

Quote:
I can go out and take a look at Leonardo's Last Supper!

..you teaser...!! :-))

Ciao.

Giancarlo
#36

You are right!!! It was Moses!

:-)

Namir


#37

Quote:
You are right!!! It was Moses!

:-)

Namir


Anyway, I find it quite amazing that you could remember this story from your childhood. Even if this one detail was a little off, the overall idea behind it was exactly to the point!

And very adequate concerning Walter B's beautiful phantom calculator that is not "talking" either - like this Mavid guy - Doses - whatever.

What a shame!

#38

HP! Move on!

-- Antonio


#39

Thanks & grazie for the friendly comments posted so far.

My apologies to Michael A. ;) but just to put a putto alongside Doses, so to say, you can use the same keys in a Voyager-sized calc:

Everything except the cursor keys is identical. Even the menu system can remain unchanged. The LCD is a standard type discussed here some weeks ago, featuring 2 lines times 40 chars. A custom LCD may be better, but this will do. Anyway, the 45S featuring a larger display looks more versatile to me.

Edited also to correct my English (hopefully).

Edited: 31 Jan 2008, 8:13 a.m. after one or more responses were posted

#40

Quote:
I would be wiling to pay for it $700 or more for it, like I paid for the 67 originally!!! (HP designers!!! Are you listening???)

They might be listening, but they aren't going to build it. The market for a $700 calculator wouldn't be more than a few hundred units at most.


#41

Eric, I really can't resist:

Quote:
The market for a $700 calculator wouldn't be more than a few hundred units at most.

That's what the marketing wonks said about the 35...

So I'm off by a couple'o hundred bucks :^)


#42

Quote:
That's what the marketing wonks said about the 35...

So I'm off by a couple'o hundred bucks :^)


The HP-35 in 1972 cost the equivalent of $1900 today. It's not surprising that marketing people would think that it wouldn't sell, given that there wasn't any existing market for scientific pocket calculators.

Today there is a well-established market for scientific calculators, and they sell for under $50 for non-graphing, and up to $200 for a high-end graphing calculator. It is unlikely that there is any significant market potential for a calculator selling for over $200, unless it has special features to address a niche market (e.g., surveying), and even for that the sales volume will be too low to attract any interest from the major players in the calculator market.

#43

Heres one referebce, there are more. Also you might google fixthatcalc Sam http://www.hpmuseum.org/guest/hoskins/67crfix.pdf

#44

I agree with Stephen (aranda1984). I own and admire 41CV since 1980. Recently, I got the new 50g. Oh I miss my 41CV! (Actually, I now carry both!!)

I bought the 50g expecting the simplicity (usage/programming and getting fast results) of a 41CX, with additional features (barrier breakers) like SD Cards instead of the Card Reader, a larger (multiline) screen, a PC connection, and a faster CPU.

However, although I knew it was somewhat different from that of a 41CX, I was heartbroken to see that the usage was way too delaying.. As an example, I miss quick storing of a number into a register by simply pressing the "STO" button.

Yes, I too, want a 41CX with a faster CPU, a large screen, an SD Card Slot, and a PC Connection. Nothing more!..

Speed, simplicity, ease of use, and low price are the *magic* words for success.

Regards,

Al


#45

... How about a HP41 Emulator for the HP48GX ?

It really works very well !!!

Antoine

#46

Quote:
As an example, I miss quick storing of a number into a register by simply pressing the "STO" button.
I did too, but found it easy to address this deficiency. I just set up a custom menu (CST) with STO and RCL functions.

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