CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?

02222017, 11:33 PM
(This post was last modified: 02222017 11:55 PM by jebem.)
Post: #1




CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
"Factoring made easy" by Casio in 1986!
Was this CASIO fx5500 the first calculator in the market able to do symbolic calculus (formula manipulation) although in a very limited format, otherwise known as C.A.S. these days? This machine belongs to another local collector that kindly allowed me to have for some time for testing. This is a handy little machine, almost of the same size and form as the HP Voyager series, although featuring totally different capabilities and operation philosophy. Main features, based on the user manual:
Forensics test: arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) ) Result: 9.000007164 the same as for the Casio fx730P among others. Doing (9Ans) *1000000 to find additional internal digits gives just 7.164. Using some expressions from the user manual examples to test the symbolic manipulation capability. Well, it is not a powerful manipulation and we can't even consider it a full C.A.S. system, but in 1986 it was something rare, if not unique, to see on a pocket calculator. Simplify 5X^2 + 7X  6  3X^2 + 2X + 9 Took about 2 seconds to find this result: 2X^2 +9X + 3 Just for fun, tried to Expand (X + 3)^5 It took about 8 seconds to find this result: X^5 + 15X^4 + 90X^3 + 270X^2 + 405X + 243 Jose Mesquita RadioMuseum.org member 

02222017, 11:52 PM
Post: #2




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
Tear down.
Back cover. Power supply: 6VDC, 0.01W Serial number suggests a date of 1986, February (6B). Removing the aluminum back cover by undoing the two screws reveals the metallic sliding battery cover. Removing the inner plastic frame by undoing eight self taping screws. Lift it at the battery side first, then use a plastic pry tool to unlatch the remaining sides leaving the display side to the end. Note the grounding/shielding spring at the lower left side, interconnecting the front face plate and back cover to the circuit common ground. The PCA is free to be removed. Lift it on the battery side first, then gently pull the display assembly to remove it from the front cover bed. Unfolding the display flat cable to uncover the main PCA components:
However, Kyoro's Room Blog documents the Casio PB770 internals and we know that it uses four of these chips for a total of 8KByte of SRAM memory. The Hitachi HD61747 processors are used in several Casio models, only changing the firmware code. For example:
Membrane keyboard using rubber keys and painted labels. Not the best solution but the painting was good and it never fails to register a key. Jose Mesquita RadioMuseum.org member 

02232017, 06:06 AM
Post: #3




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?  
02232017, 07:18 AM
Post: #4




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
(02232017 06:06 AM)Leonid Wrote: Font exponent changes only for "2"? No, at least up to 5 as seen here: https://3.bp.blogspot.com/FUqllsi3JUQ/W...00_012.jpg 

02232017, 11:03 AM
(This post was last modified: 02232017 11:37 AM by jebem.)
Post: #5




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
(02232017 07:18 AM)damaltor Wrote:(02232017 06:06 AM)Leonid Wrote: Font exponent changes only for "2"? Yap, there is no limitations concerning its ability to present exponents in superscript mode, up to the supported limits, of course. The fx5500 User Manual is available at the LeDuDu site, so you may have a more detailed look. Here is another example: Simplify 2X^6 x 3X^7 x 5X^89 + 3Y^8  7Y x 6Y^3 Result: 30X^102 + 3Y^8  42Y^4 And yet another example using huge negative exponents. It turns out that it doesn't support superscripts on negative exponents, although it changes automatically to conventional algebraic notation. Simplify 3X^9000 x 7X^76543 Result: 21 / X^67543 (about 1 second to compute this) Jose Mesquita RadioMuseum.org member 

02232017, 11:32 AM
Post: #6




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?  
02232017, 11:54 AM
Post: #7




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
@Leonid:
You have good eyes and attention to details! Yes, I see your point. When using the dedicated key "x^2", it will use a different font for the digit "2" than the one used for all the exponent digits when using the key "x^n". Jose Mesquita RadioMuseum.org member 

02232017, 12:08 PM
Post: #8




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
Maybe this was made specifically to highlight for the various algorithms and therefore different calculation accuracy for x^2 vs. x^n(n=2) ?
Check it!) 

02232017, 12:43 PM
Post: #9




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
I have checked a few calculations but it seems that it doesn't matter whether the dedicated square key "x^2" or the natural power key "x^n" are used. The results are the same.
Probably the reason is that a dedicated "x^2" key is faster to use (single key entry) than having to press two keys to get the same entry value ("x^n", "2" ). Also, using the function "x^Y" (accessed using shift over the same "x^n" key) will also give the same results. The function key "x^Y" allows to enter real numbers in the exponent, whereas the "x^n" only allows to enter natural digits. Jose Mesquita RadioMuseum.org member 

02232017, 02:54 PM
Post: #10




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
Oooh now i know what you mean. there is another one of that series which does the same thing. give me a day or two, and i will pull it out of my collection.
Yes, the font is different, because the meaning is somewhat different: The first number two, obtained by the x^2 key, is a finite action (square the number "below" it) and the second two, obtained by x^n, is only a digit in a possibly multidigit exponent. it is not possible to do "123^20" by pressing "1 2 3 x^2 0", because the two ^2 are not the same. i dont know if there is a technical reason to make the numbers different (and i highly doubt it too), but they have to be distinguished somehow as they are simply not the same. i wonder if that is mentioned in the users manual in any way. 

02242017, 02:25 PM
(This post was last modified: 02242017 02:25 PM by jebem.)
Post: #11




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
I believe we discussed something similar before for the fx5000F here.
Jose Mesquita RadioMuseum.org member 

02272017, 08:48 AM
Post: #12




RE: CASIO fx5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?
Exactly, that is the one i was searching for.


« Next Oldest  Next Newest »

User(s) browsing this thread: 1 Guest(s)