What is a Run Indicator? Funny you should ask... The Run Indicator is the marker in the upper right corner of the calculator's display that comes up when the calculator's CPU is busy doing something. Sort of like the light that flashes when your computer's busy. This tutorial will show you how to turn the Run Indicator on and off.
Let's take the Getkey program that displays the keycode of a key press program (Tutorial 8). When the program is waiting for a key press, it displays a Run Indicator in the corner of the screen. Isn't that thing annoying? Simple solution is to get rid of it.
#define B_CALL(xxxx) rst 28h \ .dw
#define B_JUMP(xxxx) call 50h \ .dw xxxx
_clrlcdfull =4540h ;The ususal constants and defines, look at the New Commands section for more information
B_CALL(_clrlcdfull) ; clear screen
B_CALL(_homeup) ; home the cursor
B_CALL(_RunIndicOff) ; Turning off the Run Indicator
ld hl,txt1 ; Display the message at the txt1 label
B_CALL(_getkey) ; Detect key press
push af ; Save key press in register a
B_CALL(_clrlcdfull) ; clear screen again
B_CALL(_homeup) ; home again
ld hl,txt2 ; Display msg2
B_CALL(_puts) ; Display text
pop af ; restore reg a
call dishex ; Follow commands at label dishex to find hex key code
B_CALL(_getkey) ; pause until next key press
B_CALL(_newline) ; Move cursor to next line
ret ;Return to TI-OS
dishex: push af ; keep copy of value
and 0F0h ; terminate lower nibble
rra ; shift nibble right 4
ld l,a ; Display the Key's hex code in Str1
push de ; keep for other nibbler
add hl,de ; add offset to hexStr address
ld a,(hl) ; find correct ASCII character from string below to display hex code of key pressed.
B_CALL(_putc) ; display character
and 0Fh ; wipeout upper nibble
ret ; Return to OS
hexStr .db "0123456789ABCDEF" ;These are the characters used to display the key's hex code
txt1 .db "Push a key.",0
txt2 .db "Key code: ",0
_RunIndicOff - Disables the Run Indicator
Related Commands Tutorial 11 Click to return
to the site's menu... or here
to get back to the tutorial's menu.
There is a ROM call that does exactly the opposite of the _RunIndicOff call, it is _RunIndicOn ( RunIndicOn = 456Dh). To use it, place it at the end of a program to turn the Indicator back on, or put in in the front of the program to make sure it is on.
Click to return to the site's menu... or here to get back to the tutorial's menu.