Note: this article is very old and was part of my website more than ten years ago. I got it back again due to my affection for that wonderful programmable calculator.
I'd like to share tricks and programs suitable for this excellent pocket computer by CASIO. I've discovered a lot of hidden features of this calculator. Do you want to try some new BASIC commands? These are not documented on the User Manual, but they are extensively used in the Scientific Library. I can also tell you how to connect your calculator to your PC with a few money.
The first is a game: The Little Castle. It uses the graphics of this calculator over their limits... you will see castles, towers, swordsmen, candles, cars, bats, treasures... you need a little bit of fantasy, this is not a 32-bit 3D Voodoo Graphics action game, but if you like FX-880P, this should be a must for you. If you enjoy this, please let me know your opinions about it. Note: the game is in Italian, but the instructions are in English. Please don't download this game if you have an FX-850P with 8kb of RAM. This is more than 10kb.
The second program is a Workshop that could help you if you need to make some calculations with error-propagation. Note: use this program only if you have an FX-880P with 32kb of memory: no FX-850P and no 64kb! This is because this program writes some memory locations with POKE, and these locations are different in other situations. I could port the program, but I couldn't test it. If you have a different configuration, you could help me. The programs and the instructions are both in English. Please feel free to translate them if you want, I only ask to leave my name and my e-mail in the instructions distributed with the program.
DEFCHR$: this is a very fun tool, allowing you to create 4 new characters. Try this program:
10 DEFCHR$(252) = "1824428244" 20 DEFCHR$(253) = "04085C0204" 30 DEFCHR$(254) = "0C120C0204" 40 DEFCHR$(255) = "0C120C00FA" 50 PRINT CHR$(252) + CHR$(253) + CHR$(254)+ CHR$(255)
This is a handwritten version of the famous program: "Hello, world!". As you can see, the syntax of this command is very simple. The argument of DEFCHR$ can be any valid expression, but its value is truncated to an integer between 252 and 255 included. These are the only ASCII codes you can modify in FX-880P. The characters can be modified every time you want, even many times in the same program, but if you change a character that is being showed on the display, it will modify immediately (this is also useful to create animations). To create the string representing the character you want to use, consider this example grid:
This is the first character used in the program. You need to sum the hexadecimal value of each cell, obtaining a two-digit number for each column. The first is 10 + 08 = 18 and so on. The final string is 1824428244.
INPUT@: this command is like the usual INPUT, but now you can define the maximum length of the input data. Consider this example:
10 INPUT@4; A$ 20 PRINT "You entered: " + A$
Try the program entering "hello" to verify the consequence of this command. The syntax can be more complex: you can include a message and multiple input, like this:
10 INPUT "Enter three numbers "; @4; A, @7; B, C
Here you can write 4 digits in A, 7 in B and all the digits you want in C. Try to press CLS while inserting A: only the data you are writing will be erased: you created a window!
INPUT$: this command is included in the User Manual, but has an undocumented feature. Here is the example used in the User Manual to explain INPUT$, with some little changes:
10 PRINT : PRINT "Enter secret code"; 20 ID$ = INPUT$(4,@) 30 IF ID$ <> "9876" THEN 10 40 PRINT : PRINT "OK"
The difference is in hiding the cursor. Unlike using INKEY$, the execution of the program is stopped until you type the exact number of characters.
CALC$: this is a system variable representing the contents of the function memory. You can always read it, but you can modify it only in the body of a program.
CALCJMP: this executes the function memory. In the CAL mode the effect is the same of the CALC key, but you can use it in a program, too.
Here is all you need to connect your FX-850P or FX-880P to your PC in a simple way. Note: if you are expert of these things, you can find on the net more detailed information. This is only a simple way to make the connection.
Take a cable like that connecting your printer to the parallel port of your PC. This should have 25 pins on the PC side and 36 pins on the printer side . Open the printer connector and search for the numeration of the pins, from 1 to 36. Write elsewhere the colors of the cables connected to the pins 2, 10, 11 and 19. The connector of your calculator should have 30 holes, and you can adopt this numeration for them:
You need to take off the 36-pin connector of your cable, so having a lot of little colored wires, but only the four you have written down before needs to be connected to your calculator, with this correspondence:
You can easily build a rough connector sticking the four wires up and down on a piece of cardboard. That's all the hardware you need. The software you must download is an editor made especially for the Casio FX-850P and FX-880P by Felipe Polo Leonor. It was written in Spanish and I haven't found an English version of it. But using it is straightforward, because it has a familiar MS-DOS interface. The main differences are the commands "Transmitir" and "Recibir" (Send and Receive). You must run this program in the true MS-DOS mode, not in an MS-DOS prompt. Suppose you have at least a program in your calculator and you have made the connection described above. Now launch the Casio Editor on your PC and choose "Recibir". You will see the instructions you need to follow to put your Casio program into your new editor. Then you could try to send this program to an empty zone on your Casio. If something goes wrong, try slowing the transfer speed in editor preferences. That's all.
Jul 12, 2008 7:59 PM
i have a fx-850p, it was stored for almost 8 years, i replaced the battery set, but it wont work. the cursor appear but shows a out of memory error or sn eror. and it's always on . if i take the batteries of it works again. do i have to replace de memory module? can you help me? im from mexico
my email: firstname.lastname@example.org
Aug 12, 2008 11:16 PM
my friend make a program in my 880p calculator, i used the program in my calculator in my work, i bought another 880P, the problem was, my friend who make the program, i cannot contact him any more, i want to open or download the program of my other 880p, how can i open the program in my 880P, i dont know the password, IT IS POSSIBLE TO DOWNLOAD OR OPEN the program in my 880P calculator. PLEASE HELP, how to open or download a program without a password.
im madelaine from philippines
my email: email@example.com
Sep 20, 2008 2:46 AM
I need some one to help me. I exchanged a very cheap calculator with an FX-880P from a colleague. The Unit is in excellent shape but my colleague doesn't have any type of connector. I read there is a connector called FA. I love the calculator and I have the manual. Since the memory is little, I would like to be able to connect to my PC and transfer any programs and/or data to the PC.
Where can I buy the original connector? Is this calculator still in production by casio?
Any helpful hint would be appreciated.
Thanks in advance.
My email: firstname.lastname@example.org
Nov 23, 2008 5:45 PM
Selling one used FX-880P in perfect working conditions alongside with it's quick reference card and manual in english format.
I have several pictures to show to those interested in buying it, and I am only selling it because I had to buy an HP 50G that suits me best for my present and future needs.
If you want it, please contact me at jrteixeira[at]gmail[dot]com.
Dec 15, 2008 9:32 AM
can you give the screenshot for the games , The Litttle Castle and Workshop ? Is there any emulator for Casio FX-880P so that I can test the programs..I'm going to buy one soon , have found it in a store , very rare
Mar 2, 2009 12:43 PM
Thank you for your excellent undocumented commands. I already knew how to draw a customized character, and that the contents of the IN section can be got with the CALC$ variable, but the new features complete my questions about how the program library was built.
Thank you again! I am very happy with my FX-880P, this is the second FX-880P i bought, but I first learned how to deal with this wonderful machine since I had the FX-850P, and for this machine I bought 32 KB memory to complete 40KB. It was stholen and then I bought the new FX-880P. One year ago I bought again the extra memory of 32 KB to complete 64KB.
Nov 30, 2009 7:08 AM
i have 2 items for sale:
1 x Casio FX 850P and
1 x Casio FX 880P
Both in (nearly) mint condition, both with manual and Library Card. Mail me for picture and to make me an offer.
Feb 28, 2010 4:54 AM
Pleased to write that I am in need of the following item and request you
to kindly quote price on the basis of FOB/C&F Lahore Air Port Lahore Pakistan by Air in US$.
S. No.. Item Description Qty:
01 CASIO CALCULATOR MODEL: FX-880P 8No,S
With best Regards,
A-37 MIAN MIR SHOPING
CENTRE SADDAR LAHORE
Aug 17, 2010 6:28 AM
Hi I have a personal computer Casio Fx -880P 32 kb
Just only two question
If change the battery of memo all the programs that are saved can loses
If can do reset what hapen , my be any sofware as surveyor marine repor cam deleaying
Pls how can we put in ready command the mode 9 ore mode 0+in, because this items not working
Dec 16, 2010 1:03 AM
Hello Every Body,
I have Casio FX-880P.i need land survey Programmes like Horizontal and Vertical Curve,super elevation. if some body have this type of formulas in written form kindly mail me.I will be very thankful to you.
My e_mail adress is : email@example.com
Oct 11, 2012 7:30 AM
I m niazi civil engineer and surveyor,i have fx 880p calc,bt during the changing of betry cell ,all data removed from memo,and ,hanging now,plz where i repaire,it,if some body have graphic calculater or fx 880 p ,plz contect,00923026350575,slam to all surveyor brothers.
Oct 11, 2012 7:44 AM
aa,all surveyors brother when u,change the bettery cell of casio fx 880p ,plz confirm it ,that there are 3 betry cal 2 power cell and one littel memory cell ,between the betry cel first of all change 2 power cell and at last change memory cell,in this condition u r extra memory will be safe ,thank u.