TI-80 Euclidean help.

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Summary:

I know this isn't the right forum but it was the best I could find.

TI-80 Euclidean help.

Megah 14 Oct 2010 13:59

Hey.
I'm trying to program my old TI-80 to use the Euclidean algorithm, without luck. I'm not a good programmer when it comes to this programming language but I'd like to learn. I've seen TI-83 programs using the Euclidean but no luck in finding one for my TI-80 so I was hoping someone could help.

Sofar (it's not much) I've got this

DISP "A"
INPUT A
DISP "B"
INPUT B
{A,1,0}->L1
{B,0,1}->L2

and then I'm stuck, because of the lack of pre-defined programming functions
Help greatly appreciated

Re: TI-80 Euclidean help.

Matthias1992 14 Oct 2010 14:16

this will help:(http://education.ti.com/downloads/guidebooks/graphing/80/80book_eng.pdf) I can already give you a first optimization:

INPUT "A",A
INPUT "B",B

At page 186 of the document given above is a list off all the available commands. At page 152 and a few more pages are some example programs to get you familiar with the language, I recommend to make some of those examples first and post any questions you have about them here…
Please remember this little 'trick' whenever a program gets 'stuck' or doesn't seem to work press the 'ON' button this will give you a menu with

1: Quit
2: Goto

to stop the program hit Quit, to go to the place the program was at hit Goto. Don't be scared to expirement, Ti-Basic is a interperted language and can do zero harm to your calculator…

Good luck!

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Re: TI-80 Euclidean help.

Megah 14 Oct 2010 14:23

Fast reply, thanks!
I had problems finding less than or equal to, etc but that guide showed me how! Thanks hopefully I'll be able to solve this.

Re: TI-80 Euclidean help.

Matthias1992 14 Oct 2010 17:12

As do I, once again if you have trouble with comprehending some commands or just any other related problem in general, feel free to ask!

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Re: TI-80 Euclidean help.

Megah 14 Oct 2010 17:45

Well I think I got it. I'm not really that good at math but C&C on this please.

INPUT "A",A
INPUT "B",B
LBL D
IF (A<B)
THEN
A->E
B->A
E->B
END
IF (B≠0)
THEN
REMAINDER(A,B) -> C
B->A
C->B
GOTO D
ELSE 
DISP C
STOP

One question tho, how can I add a new line in the middle of code? So that every function below the line I'm currently at moves down one step.

Last edited on 14 Oct 2010 17:45 by Megah Show more

Re: TI-80 Euclidean help.

Yatzy 14 Oct 2010 19:08

Euclides algorhitm was my first program aswell, it's really easy to get started with the programming once you know the basics :D.

To insert something in the middle of a code, press Second then Del. This will give you the insert function, and it will last as long as you don't press an action button.

Now regarding your program, I guess the largest number switcher works for now but you might want to avoid it later. However, you're making an unecessary loop at this point:

B->A
C->B
GOTO D

Why check if A is bigger than A once again? Think about it, the remainder will always be smaller than the number you divided with, otherwise you could have divided with the number once again. Therefore B will never be larger than A after the first loop.

Also, I suggest that you try to avoid using Label and Goto for this program, and read about the "while command" :

http://tibasicdev.wikidot.com/while

Then try to figure out a neat way to replace the label with the command.

Good luck!

Last edited on 14 Oct 2010 19:12 by Yatzy Show more

Re: TI-80 Euclidean help.

burr 14 Oct 2010 19:57

The TI-80 doesn't have the While loop; it only has the For( loop. Maybe you could do something like this instead? It assumes that the first time through B will not equal zero.

INPUT "A",A
INPUT "B",B
IF A<B
THEN
A->C
B->A
C->B
END
LBL D
REMAINDER(A,B)->C
B->A
C->B
IF B
GOTO D
DISP C

Re: TI-80 Euclidean help.

Megah 14 Oct 2010 22:18

Thanks for the replies. Yatzy you are correct that the remainder will never be bigger, thanks for that. Yeah I had to create a while loop myself wit the LBL and GOTO, I know it's never good to use GOTO but this is a such a small and easy program so it'll have to do =).

burr thank you for your reply however what does

IF B
GOTO D

do exactly?

Re: TI-80 Euclidean help.

BlakPilar 14 Oct 2010 23:53

Using something like just "IF B" checks for a "True" or "False" value. If B has a value of any number that is NOT zero, the value will result in "True", or 1. If B = 0, then the result "False" will be returned, or 0.

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Projects: BexIDE (hold), Hadean.NET, Legend of Zelda: Link to the Future

Re: TI-80 Euclidean help.

burr 15 Oct 2010 19:54

Yeah, that is how the TI-83/84/+/SE calculator evaluates an expression. I don't know the TI-80 calculator, so you just have to try it out and see if it works. How is the programming going?

Re: TI-80 Euclidean help.

Megah 18 Oct 2010 10:52

Ok thanks for that explanation
It's coming along fine, thanks for your help.