This program will demonstrate how to use key presses in TI-Basic(83,84)
First the program:



So, to break it down.



Sets C and G variables to 0.
Sets X and Y to 8 and 4 respectively.
This will put the cursor in the middle of the Home screen when you start.
C is used to keep the while loop running.
G is where we will store the keypress.
X and Y are Horizontal and Vertical position, respectively.



Lets you choose any character to use as a cursor.



Loops the program until the user ends it.



Refreshes the screen every time the program loops



If a key is pressed, it stores the number of the key into the variable G



outputs the position of the cursor (Str0) to the coordinates Y, and X Respectively. This changes every time the program loops.



The key number for left is 24 and the key number for right is 26.
This line says “take X +(1 or 0 :evaluate if the right key is pressed or not and return a value of 1 if yes or zero if no) - (1 or 0 :evaluate if the right key is pressed or not and return a value of 1 if yes or zero if no)”

Example:

If the right key is pressed:
X+(1)-0→X //moving 1 forward on the x axis

If the left key is pressed:
X+(0)-(1) →X //moving 1 backward on the x axis





The key number for up is 34 and the key number for down is 25.
This line says “take X +(1 or 0 :evaluate if the up key is pressed or not and return a value of 1 if yes or zero if no) - (1 or 0 :evaluate if the down key is pressed or not and return a value of 1 if yes or zero if no)”

Example:

If the right key is pressed:
X+(1)-0→X //moving 1 forward on the y axis

If the left key is pressed:
X+(0)-(1) →X //moving 1 backward on the y axis



45 is the clear button. This goes to label Z9 if the clear button is pressed, exiting the program



The edges of the home screen is 0 to 16 on the x axis, and 0 to 8 on the y axis.
This series of if statements says that if the cursor goes over the edge of the screen, put it back at the edge.



Ends the while loop instance



If the clear key is pressed, the program goes to label Z9, and clears the home screen.
Output(1,1,” stops Done from being displayed when the program is done running.

wow! TI-BASIC, haven't used that since high school.

Yeah, it has been a while. I had some days bored in class...