include "tios.h" ;The include file for the TI-OS in the calculator.
 include "util.h" ;Utilities include file
 xdef _main       ;Label to jump to when the program starts
 xdef _comment    ;Pointer to the comment that appears in Doors OS/Plusshell
 xdef _ti89       ;This program is designed for the TI89

WriteStr macro    ;A macro. This does not save bytes. Every time this macro is called, it is included in the program again.
 move.w \3,-(a7)  ;Set the font to display the words in. Can be white on black, black on white, "xor" (inversed), and some other stuff.
 pea \4(pc)       ;Point to the string to display
 move.w \2,-(a7)  ;Where to start the string vertically
 move.w \1,-(a7)  ;Where to start the string horizontally
 jsr tios::DrawStrXY  ;call tios and put the string on the screen
 lea 10(a7),a7    ;Fix the stack pointer. (I have no idea why I must do this, e-mail me if you do.)
 endm             ;End the macro.

_main:                        ;Defines the _main label. The main loop of the program.
 jsr util::clr_scr            ;Clear the screen, using the util library.
 WriteStr #1,#1,#1,message    ;Put string "message" at 1,1 on the screen
 WriteStr #1,#9,#1,messageb   ;Put string "messageb" at 1,9 on the screen
 WriteStr #1,#17,#1,messagec  ;Put string "messagec" at 1,17 on the screen
 WriteStr #1,#25,#1,messaged  ;Put string "messaged" at 1,25 on the screen
 jsr util::idle_loop          ;Wait for a keypress, store keypress in d0
 cmp #51,d0                   ;See if keypress is key #51, or the button marked 3 w/o 2nd, diamond, shift, or alpha
 beq _exit                    ;If the key truly is the 3 key, go to the label _exit
 jsr util::clr_scr            ;Use the util libary to clear the screen.
 WriteStr #1,#1,#1,messagee   ;Put messagee at 1,1 on the screen
 jsr util::idle_loop          ;Wait for a keypress, store keypress in d0
 jmp _main                    ;Go back to label _main

_exit:                        ;Label this secion _exit
 jsr util::clr_scr            ;Clear the screen using util
 WriteStr #1,#1,#1,messagef   ;Put messagef on the screen at 1,1
 WriteStr #1,#9,#1,messageg   ;Put messageg on the screen at 1,9
 jsr util::idle_loop          ;Wait for a keypress, store keypress in d0
 rts                          ;Exit the program!

;This is the data section. The entire data section is comprised of strings, which have been displayed in the above program.
;Note to newbies: make sure you always have dc.b and ,0! :)

_comment: dc.b "Mogsoft's Secret Button 1.0",0
message: dc.b "Welcome! You cannot exit",0
messageb: dc.b "this program until you",0
messagec: dc.b "find the secret key.",0
messaged: dc.b "(Hint: It's not 3!)",0
messagee: dc.b "Incorrect. Try again.",0
messagef: dc.b "Wow! How'd you figure that",0
messageg: dc.b "out?! You're psychic!",0

 end ;End the source. In your programs, MAKE SURE THERE'S A BLANK LINE AT THE END! :)