CASIO fx-4000P scientific calculator from 1986

[edryer]

Well of all Casio calculators I suspect the pinnacle was the FX-501P/502P and FX-601P/602P and these are definitely not cheap, snapped up on eBay pretty quickly, or bidding becomes high.

If the HP-41C/CV had a competitor other than the TI-58C/59 these probably would have made the grade, not sure of any other calculator of that period 1979-1982 that could also compete.

[Csaba Tizedes]

(09-26-2018 04:54 PM)Dave Britten Wrote:  most Casios are really cheap compared to just about any HP.

As I can see the pricing of CASIOs on ebay this is not true. The valuable CASIOs price is typically higher than the HPs.

(09-26-2018 04:54 PM)Dave Britten Wrote:  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.

Actually this is true

Csaba

[Csaba Tizedes]

(09-26-2018 04:55 PM)edryer Wrote:  Well of all Casio calculators I suspect the pinnacle was the FX-501P/502P and FX-601P/602P and these are definitely not cheap, snapped up on eBay pretty quickly, or bidding becomes high.

If the HP-41C/CV had a competitor other than the TI-58C/59 these probably would have made the grade, not sure of any other calculator of that period 1979-1982 that could also compete.

Unfortunately these calculators price is pushed up by collectors and the ebay sellers who has only half-information about these units.

I had two 602P and I traded it because on these units no linear regression by default and this is the greatest fault (that is why 61F also unvaluable for me - and for the practicing engineers, but the 61F also a rare unit (I have one in perfect condition for safety )).

The 602P with LR is a perfect calculator. A 4000P with indirect addressing (of labels) also the perfect competitor. But both of them has a little deficiency.

Csaba

[Dave Britten]

(09-26-2018 07:45 PM)Csaba Tizedes Wrote:  As I can see the pricing of CASIOs on ebay this is not true. The valuable CASIOs price is typically higher than the HPs.

Yeah, some of the very early models are quite expensive, but if you stick to the calculators (i.e. not "pocket computers"), then most of the models released after the mid-1980s are very affordable. I think I paid around $30-40 each for the fx-4000P and fc-200, $10 for a new-in-box fx-6300G, and about $15 for a lovely fx-9700GE (top of the line as far as the 1st-gen array-memory models go). I've also picked up a few other assorted models for prices somewhere in that spread. The old CFX 3-color-LCD models are comparably priced.

I've purchased very few HPs for less than those prices, and the ones I did were generaly either parts machines/fixer-uppers, or horrible, like the 9g.

[toml_12953]

Does anyone know why the Casio S100 is so expensive? It looks like an ordinary four-banger calculator to me.

I'm happy enough with my fx-9860GII SD USB Power Graphic 2.

[cdmackay]

(09-26-2018 09:26 PM)toml_12953 Wrote:  Does anyone know why the Casio S100 is so expensive? It looks like an ordinary scientific calculator to me.

I'm happy enough with my fx-9860GII SD USB Power Graphic 2.

special edition, cast from solid aluminium like a Macbook, etc...

[Csaba Tizedes]

(09-26-2018 07:16 AM)Csaba Tizedes Wrote:  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?

OK, the question is open: how to clean it inside without kill the contacts of the keys?

Thanks!
Cs.

[jebem]

(09-26-2018 07:16 AM)Csaba Tizedes Wrote:  

(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

Well, I have the same issue with these old machines.
There are several causes for the same symptom on poor LCD contrast; defective power supply is one, but other causes are a bad electrical continuity somewhere in the PCB traces, or a defective resistor or capacitor, and the LCD itself can degrade with time as well.

As for the defective key, I am sure that it can be fixed as long as the PCB conductive traces are not totally depleted or contaminated with battery leakage.

A continuity meter (ohm meter) is a required tool in these cases. You can compare a good working key against the defective one, BEFORE starting to mess around with the key foil. The normal resistance value will vary, depending on the model. In this way we can compare a good key with the suspect one. The resistance value can be as low as 10 or 20 Ohm, but I saw many working machines operating with much higher values in the hundreds of Ohm.

The keyboard foil can be removed, as long as we do it with caution to not destroy it. Try to apply some heat from a air dryer over the foil and start to lift it from a corner, slowly, preferably from the side of the defective key. There is no need to remove it completely, just lift it enough to see what the problem is.
Usually I use cotton buds with IPA to clean the dirty/oxidized/contaminated area in the key contact. Do not rub too much or the conductive material can be totally depleted, and then it will almost impossible to restore it.

Be aware to not abuse on the IPA over the PCB. In any case, let it dry completely for an hour or so, before applying energy to the machine.

God luck with your repair.

Note: IPA = Isopropyl alcohol

[Csaba Tizedes]

(10-01-2018 08:59 PM)jebem Wrote:  God luck with your repair.

Thanks, I will try it this weekend!

[cdmackay]

I just got a new-in-box 4000P from TAS, for £40, which I thought not too bad.

Turned out to be new-in-sealed-box, which I didn't expect.

So, everything pristine, but still had the original 1985 CR2032 lithium batteries fitted (not working). I was a little nervous on opening it up, but it's OK: one battery had leaked just a tiny bit. I scraped off the terminals, and fitted new batteries, and it's working well.

[jebem]

(06-05-2019 10:46 PM)cdmackay Wrote:  I just got a new-in-box 4000P from TAS, for £40, which I thought not too bad.

Turned out to be new-in-sealed-box, which I didn't expect.

So, everything pristine, but still had the original 1985 CR2032 lithium batteries fitted (not working). I was a little nervous on opening it up, but it's OK: one battery had leaked just a tiny bit. I scraped off the terminals, and fitted new batteries, and it's working well.

That's a rare find for sure!
For that asking price I can only find well beaten ones. Fortunately these series are robust and easy to open. A proper cleaning and they become ready for a second life.

[cdmackay]

thanks José, yes, I was pleased to get it for that price. I'd been watching for one for ages, and luckily it was a Buy-it-now so I was able to pounce quickly when I saw it.

That completes my mini 'P' collection (I think): 3400, 3600, 3800, 3900, 4000. Now I need some time to play with them all and work out which I like best.

The 3800 is I think the last of the traditional segment LCD display models, which is the display I had on my Casio's at school, in the 80s, so I have a soft spot for that, compared to the (arguably better) pixel display on the 3900/4000.

But only the 3400/3600 have the a/b/c fraction key, which I also like; shame they dropped it from the later models.

I'm not interested in the later models in this line, e.g. 4500P, as I prefer the silver/beige looks of the above (again matching the scientific Casios I had at school). I think everything after the 4000P was darker?

Although I also have a 700P and a 7000G that I used at Univ. must dig those out for a play, too.

[Dave Britten]

I'd recommend getting ahold of an FC-200 (not the newer FC-200V) if you haven't already. It's an excellent financial calculator, and while it's lacking depreciation and bond calculations, I find it much nicer to program than the 12C, meaning you could implement those functions fairly easily, and still have room for more programs.

http://casio.ledudu.com/pockets.asp?type=98&lg=eng

Or you can just play with the TVM/amortization package I wrote for scientific models. This should work on any Casio with array memories (i.e. models with a "Defm" function, which is just about all of them up through the fx-9700GE and cfx-9800G).

http://dave.brittens.org/blog/casio-tvm-...ation.html

[grsbanks]

(06-06-2019 12:33 PM)cdmackay Wrote:  Although I also have a 700P and a 7000G that I used at Univ. must dig those out for a play, too.

The 7000G is a similar colour scheme to the 4000P, just with a bigger screen for the graphing capability and with rubber keys.

I'm actually quite fond of that series of graphing calculators. Still on the look-out for a 6500G as I already have several 7000G/GA/GB machines, a couple of 6000Gs and 7500Gs, an 8000G and an 8500G.

[cdmackay]

(06-06-2019 03:02 PM)grsbanks Wrote:  The 7000G is a similar colour scheme to the 4000P, just with a bigger screen for the graphing capability and with rubber keys.

I'm actually quite fond of that series of graphing calculators. Still on the look-out for a 6500G as I already have several 7000G/GA/GB machines, a couple of 6000Gs and 7500Gs, an 8000G and an 8500G.

Ah! didn't realise you were into Casio too

Yes, I liked the 7000G a lot, seemed ground-breaking at the time (although I wasn't familiar with HP then).

Looks like I have some more collecting to do!

[cdmackay]

(06-06-2019 01:28 PM)Dave Britten Wrote:  I'd recommend getting ahold of an FC-200 (not the newer FC-200V) if you haven't already. It's an excellent financial calculator, and while it's lacking depreciation and bond calculations, I find it much nicer to program than the 12C, meaning you could implement those functions fairly easily, and still have room for more programs.

http://casio.ledudu.com/pockets.asp?type=98&lg=eng

Or you can just play with the TVM/amortization package I wrote for scientific models. This should work on any Casio with array memories (i.e. models with a "Defm" function, which is just about all of them up through the fx-9700GE and cfx-9800G).

http://dave.brittens.org/blog/casio-tvm-...ation.html

thanks! will look into those…

[Dave Britten]

(06-06-2019 03:56 PM)cdmackay Wrote:  

(06-06-2019 03:02 PM)grsbanks Wrote:  The 7000G is a similar colour scheme to the 4000P, just with a bigger screen for the graphing capability and with rubber keys.

I'm actually quite fond of that series of graphing calculators. Still on the look-out for a 6500G as I already have several 7000G/GA/GB machines, a couple of 6000Gs and 7500Gs, an 8000G and an 8500G.

Ah! didn't realise you were into Casio too

Yes, I liked the 7000G a lot, seemed ground-breaking at the time (although I wasn't familiar with HP then).

Looks like I have some more collecting to do!

The nice thing about collecting Casio graphers is that they're (almost) all so cheap. You can get a whole bunch of them for the price of one nice HP48GX!

I really like the sleek, rugged design of the fx-7700G. I'm still trying to track down an 8700 or 8800, which has more memory. I wish they hadn't dumped the array/indirect variable addressing with the later generations!

[ijabbott]

(06-06-2019 12:33 PM)cdmackay Wrote:  thanks José, yes, I was pleased to get it for that price. I'd been watching for one for ages, and luckily it was a Buy-it-now so I was able to pounce quickly when I saw it.

That completes my mini 'P' collection (I think): 3400, 3600, 3800, 3900, 4000. Now I need some time to play with them all and work out which I like best.

The 3800 is I think the last of the traditional segment LCD display models, which is the display I had on my Casio's at school, in the 80s, so I have a soft spot for that, compared to the (arguably better) pixel display on the 3900/4000.

But only the 3400/3600 have the a/b/c fraction key, which I also like; shame they dropped it from the later models.

They also dropped the bitwise logic operations (but kept the BIN/OCT/HEX/DEC arithmetic) between the fx-3400P and fx-3600P, added them back in for the fx-3600Pv (another one for you to seek out), and removed them again for the fx-3800P. (EDIT: There also seems to be a fx-3600PV (with a capital V) that doesn't have the bitwise operations, just to confuse things further! EDIT 2: That one seems to be a fake Casio according to this.) Somewhat annoyingly, I bought a fx-3800P from a major UK stationers back in the day and didn't discover the lack of bitwise operations until it was too late.

[grsbanks]

(06-06-2019 03:56 PM)cdmackay Wrote:  Ah! didn't realise you were into Casio too

If it's a programmable, I'm into it All in all I have about 180 calculators from various brands, but mainly HP, TI and Casio.

(06-06-2019 03:56 PM)cdmackay Wrote:  Yes, I liked the 7000G a lot, seemed ground-breaking at the time (although I wasn't familiar with HP then).

It was groundbreaking. The 7000G was the first graphing calculator brought to market!

[cdmackay]

(06-06-2019 04:12 PM)Dave Britten Wrote:  The nice thing about collecting Casio graphers is that they're (almost) all so cheap. You can get a whole bunch of them for the price of one nice HP48GX!

especially given what I paid for my 48GX, as I wanted one of the last with the black LCD

(06-06-2019 04:20 PM)ijabbott Wrote:  They also dropped the bitwise logic operations (but kept the BIN/OCT/HEX/DEC arithmetic) between the fx-3400P and fx-3600P, added them back in for the fx-3600Pv (another one for you to seek out), and removed them again for the fx-3800P. (EDIT: There also seems to be a fx-3600PV (with a capital V) that doesn't have the bitwise operations, just to confuse things further! EDIT 2: That one seems to be a fake Casio according to this.) Somewhat annoyingly, I bought a fx-3800P from a major UK stationers back in the day and didn't discover the lack of bitwise operations until it was too late.

sigh; I'd not really looked into the Pv models, assuming them to be non-UK, on which I was concentrating. But now I think I will have to!

(06-06-2019 04:50 PM)grsbanks Wrote:  If it's a programmable, I'm into it All in all I have about 180 calculators from various brands, but mainly HP, TI and Casio.

It was groundbreaking. The 7000G was the first graphing calculator brought to market!

180? crikey! that makes me feel better

I thought the 7000G was the first, thanks for confirming.