CASIO fx-4000P scientific calculator from 1986

[jebem]

This small pocket calculator was manufactured in Japan after 1986 week 43 according to the most recent chip date found in the PCA of this specimen.

The year is 1985.
Casio released this model with an impressive set of features for its time:
- Re-configurable RAM memory partitioning. Default values are 26 x 8-byte registers and 550 programming steps.
- Fully merged programming model.
- Conditional and unconditional jumps, subroutines.
- Support for indirect register addressing.
- User friendly programming environment. Keystrokes displayed by its function names. Easy editing and debugging.
- Alphanumeric capability.




Calculator forensics: arcsin(arccos(arctan(tan(cos(sin(9)))))) = 8.999686999
Remaining digits: 9 - Ans Exe x 10000000 = 31.3001




5x7 dot matrix LCD display, natural language algebraic input.



Friendly program editor.
Keystrokes displayed by its function names.
Left and right cursors allows easy editing.
Program memory usage updated in real time at the top right.




Dot matrix LCD display with full contrast ON to show all elements.




Accessing the battery compartment.
It uses two CR2032 in series for a total of 6Volt at 1.7mA average current consumption.



(to be continued)

[jebem]

And as expected, I had to dismantle the machine for cleaning and checking.

This specimen had poor LCD contrast.
The issue was fixed after cleaning the battery holder connection pads on the PCA.







SoC processor: Hitachi HD61747B38 6J 43 (1986 week 43)
Memory: HD61914 8kbit static RAM 6K33 (1986 week 33)
This is the same PCA as used on the FC-200 financial calculator, but using a different firmware.

[Tugdual]

Compared to the recent hp made in China, the design of these old Casio is very impressive.
I'd love to own one of these old Casio. Is it as robust as it looks like? Easy to open and clean?

[jebem]

(12-20-2015 08:42 AM)Tugdual Wrote:  Compared to the recent hp made in China, the design of these old Casio is very impressive.
I'd love to own one of these old Casio. Is it as robust as it looks like? Easy to open and clean?

These machines are robust and easy to clean, but the weakest point is the keyboard operation. The key travel is very short and mushy, nothing compared to what we expect from a proper genuine HP machine (or from the latest SwissMicros for that matter).
On the positive side, the key registration is very reliable, contrary to what some recent HP calculators like the HP-30B are doing (despite a positive mechanical action, the registration is not always reliable, be it because there are quality control issues or any other reason).

[Chasfield]

This is my hierarchy of preference for calculator keyboards:

1) Positive tactile action and reliable (my HP11C)
2) Mushy action and reliable (my Casios and Sumlock Anitas)
3) Positive tactile action and unreliable (my Texas TI59, HP30B, and Sinclair Scientific)
4) Mushy action and unreliable - quite rare, I think

Ergonomically speaking, the worst keyboard I have is on my Novus Mathematician. It provides no tactile feedback whatsoever and the spring rate is unpleasantly non-linear, giving the feeling that the key is about to snap off at the limit of its travel. However it responds reliably and doesn't generate double presses.

I think Texas scared quite a few customers off around about the time of the TI57 (and its numerous cousins rendered in similar hardware). Those were very poor units and, in the main, their leaky NiCads sent them to an early grave.

[Eddie W. Shore]

I have something similar, the Radio Shack's version of the fx-4500p.

[vido]

The CASIO FX-4000P was a very good machine, you could keep 10 different programs into permanent memory, programs could call each other as subroutines, allowing to start in a given mode (typically the "normal" mode), make some calculation in a different one (SD, LR, even Base-N for example), display/pause or wait for user input to continue, use loops to fill indexed arrays (memory was 2kb, allotable between up to 550 steps/26 memories and 0 steps/lots of memories). Display was alpha only (no graphics) but there was a large character set. The language was not BASIC but a cleverly designed one, offering much of what to expect from a programming language.
There was a hack I stumbled on accidentally some day, allowing to have both 2000 steps and the max number of memory (simply said, the pointer to the end of the program area or the beginning of the memories area was set to an impossible value which gave "god mode" and unprotected access to the whole memory from either perspective). Needless to say, you could be overwriting programs with the content of some memories, which unlocked hidden functions and characters such as percentages, imaginary numbers and probably more. You could also very easily lose access to the already written programs, so this was to be handled with great caution.
I used this small beastie a lot at the time, and the only things I could gripe upon were that I would have loved to have a few kb more memory, and some I/O to store/retrieve programs and data.
The next models were a crippled version without a real programming language, just some "function definition" capability, or buffed up versions with more memory and display lines, but more massive already, which made them less convenient to keep in a shirt pocket.
Then the graphical calculators came, but they were too bulky and contained too much useless crapware for a comfortable use outside a classroom.

The FX-4000P was an exceptional calculator by CASIO. They could remake it the same size, with maybe a retrolit keyboard and 2-line screen allowing some pixel-level access, as well as the possiblity to read a keypress without waiting for a ENTER, some good memory amount and a SD Card reader, without sacrificing the convenience of a keyboard allowing ALPHA entry, and it would be great.

There is a CASIO fx-FD10 "pro" model which comes very close to this, but they committed the sin of getting rid of convenient access to Alpha entry mode, as well as most key 2nd functions, in favor of a confused menu system. Plus, it stinks of truck wheel rubber (Incredible !). Although I was quite disappointed when I discovered programming on the go is made very inconvenient, I won't resell that one, but I do hope there might be an update in the right direction some day.

[Dan C]

Hi!

I just got this wonderful calculator, but the front panel is little loose on one side.
I wonder, is the front attached with screws? or glued? or just double sided adhevise tape?

[Dan C]

(01-09-2017 05:36 AM)vido Wrote:  There was a hack I stumbled on accidentally some day, allowing to have both 2000 steps and the max number of memory (simply said, the pointer to the end of the program area or the beginning of the memories area was set to an impossible value which gave "god mode" and unprotected access to the whole memory from either perspective).

WoW! How do i get 2000 steps? What must i type in to get this?

[badaze]

In my opinion it is far better than the 602P it replaced. Fortunately the 4000P is affordable (unlike the 602P) and easy to find. I bought several for a few € at flea markets even boxed.
It is rare to get a non working one - the last I bought at a charity store - but its weakness resides in the front bezel that often detach.

PS : I’m really interested in the 2 KB trick.

[ijabbott]

(07-29-2018 07:07 PM)badaze Wrote:  In my opinion it is far better than the 602P it replaced. Fortunately the 4000P is affordable (unlike the 602P) and easy to find. I bought several for a few € at flea markets even boxed.

The main thing lacking compared to the 602P is the ability to connect to an external cassette tape interface for loading/saving programs, or playing tunes. ("I'm the operator on my pocket calculator.")

Quote:It is rare to get a non working one - the last I bought at a charity store - but its weakness resides in the front bezel that often detach.

They seem readily available on eBay, including some listings with the operations manual. I may get one for nostalgia's sake. (I had a 502P back in the day.)

[Jlouis]

(07-29-2018 08:36 PM)ijabbott Wrote:  

(07-29-2018 07:07 PM)badaze Wrote:  In my opinion it is far better than the 602P it replaced. Fortunately the 4000P is affordable (unlike the 602P) and easy to find. I bought several for a few € at flea markets even boxed.

The main thing lacking compared to the 602P is the ability to connect to an external cassette tape interface for loading/saving programs, or playing tunes. ("I'm the operator on my pocket calculator.")

Quote:It is rare to get a non working one - the last I bought at a charity store - but its weakness resides in the front bezel that often detach.

They seem readily available on eBay, including some listings with the operations manual. I may get one for nostalgia's sake. (I had a 502P back in the day.)

I bought a few years ago for very cheap a NOS 4500P, which is the 4000 with more memory and programing step and I found it excelente, built quality, functions etc. A superb calculator.

As for

("I'm the operator on my pocket calculator.")

I think I found a Kreftwerk fan like me here in this very forum...

Cheers

JL

[Thomas Klemm]

(07-29-2018 09:04 PM)Jlouis Wrote:  I think I found a Kraftwerk fan like me here in this very forum...

Not the only one.

Cheers
Thomas

[Joe Horn]

(07-29-2018 09:04 PM)Jlouis Wrote:  I think I found a Kraftwerk fan like me here in this very forum...

By pressing down a special key
It plays a little melody:

[hp41cx]

Casio VL-80 - Kraftwerk music

[Dan C]

That's quite interesting, I have seen many quotes of Kraftwerk playing Pocket Calculator on an Casio FX-602p, but I newer seen an Video of it These Videos posted here are for sure not an FX-602p played on.
Maybe its an urban myth?

[ijabbott]

(07-30-2018 08:22 PM)Dan C Wrote:  That's quite interesting, I have seen many quotes of Kraftwerk playing Pocket Calculator on an Casio FX-602p, but I newer seen an Video of it These Videos posted here are for sure not an FX-602p played on.
Maybe its an urban myth?

I think it was an FX-502P. All the image designs for the single releases were based on the FX-502P (or possibly the FX-501P).

http://www.casio-calculator.com/Collecto...kTape.html
https://www.discogs.com/Kraftwerk-Pocket...ase/521314
https://www.discogs.com/Kraftwerk-Tasche...ase/160195
https://www.discogs.com/Kraftwerk-Pocket...e/10917250

[Csaba Tizedes]

(12-05-2015 03:25 PM)jebem Wrote:  This specimen had poor LCD contrast.
The issue was fixed after cleaning the battery holder connection pads on the PCA.

I have two workable units, one of them in perfect condition, the other is my daily used machine for calculating dawn-sunrise-noon-sunset times for my location.

Both of them has the problem with contrast: typically the contrast set is OK, but sometimes goes too poor and sometimes too dark, but the battery is new. Have you got any idea how this is fixable? If I turn off/on the unit the contrast set is fixed for a long period then starts again the changing.

Another question: the second unit is arrived this Monday and really like a new but as I can feel the bracket [(] [)] keys response is poorer than others. I will clean the unit inside, my question is between the keyboard foil and PCB is it required to clean or that will kill the contacts? Is it possible to clean the foil itself? What is the right cleaning liquid?

Thanks for the answers!
Csaba

[burkhard]

When in college with my 15C in the late 1980s, I remember a few friends with Casios like this or very close. I liked them a lot except for the cardinal sins of being non-RPN and rather mushy non-click buttons. But, a decent display and very pocketable!

I must restrain myself from branching my collection into old Casios as well. Stop. Stop now.

[Dave Britten]

(09-26-2018 01:25 PM)burkhard Wrote:  When in college with my 15C in the late 1980s, I remember a few friends with Casios like this or very close. I liked them a lot except for the cardinal sins of being non-RPN and rather mushy non-click buttons. But, a decent display and very pocketable!

I must restrain myself from branching my collection into old Casios as well. Stop. Stop now.

The good news is that most Casios are really cheap compared to just about any HP. You can probably get a whole sack full of them for the cost of one nice 15C or 42S!

Also, the array-style memory addressing of their older models (up through what Wikipedia calls the 1st generation of graphing models) makes it super easy to create a MISO-style solver using the secant method. Thus you can do very user-friendly - and accurate - TVM on a 4000P, and still have a few hundred bytes left over for an amort routine. When looking at other models, if you see "Defm" somewhere on the keyboard or in the Mode key reference, it probably functions the same way. Later models added list variables but removed the ability to address A-Z variables with array indexes/relative offsets.