There's no reason why my script isnt working:
(Do I have to post what's "inside" the calls? I dont think its relevant...)
*some codes*
CALL newsprr1n1 ;Just some stuff, not important I think...
LD B, 6 ;
CALL hidemoveshowncount ;
JP Label ;Gets executed, nothing wrong

;But if I do this:
*some codes*
CALL test123 ;Ram-Reset :C
JP Label ;Doesn't get executed. Ram resets the previous line.

test123:
CALL newsprr1n1 ;The EXACT same stuff!
LD B, 6 ;
CALL hidemoveshowncount ;
ret

What is the matter?
Am I missing something obvious?
Why does the call result in a crash?

MAYBE it has something to do with the fact that my program is over 8kB.
I've read (in the ASM-in-28-Days tutorial) that I should keep programs for the TI 84+ below 8kB, but that's impossible since I'm making a game.
But why shouldnt programms be larger then 8kB?

That might not be related to the errors though, I'm just guessing (and I want to know what's the deal with that 8kB limit).

ANY help at all would be greatly appreciated!

*EDIT*

Okay, I'm quite sure it has something to do with the limit now.
I moved the piece of malfunctioning script from the bottom of my script to the top, and now it's working perfectly fine.
Please explain the WHY, and HOW I fix it?

Another alternative is to try to turn as many things as possible into data form. For example, in a RPG, if you got NPC convos, store them into memory, same for NPC patterns, enemy stats, possible attacks in battles, or if you're making an action game, store bosses movement pattern into data too instead of hardcoding it. Data doesn't count in that 8 KB code limit since it's not code, just the action of storing the data in memory takes code space.

Yeah, I get those all the time.  Once when I was dealing with interrupts, I forgot to save the ix register in my interrupt code and so the program would occasionally start doing some cray stuff and I couldn't find the error anywhere and it took me at least a week to find it after disassembling it line for line and finally realized there was no error.

When I say "outside the main program" I just mean anywhere in the ram, you wouldn't want to write it to a program or any user variable.  It gets confusing becasue you have to change your pointers around when making absolute calls, jumps, and loading and saving from ram since the locations are different than your code.  Fortunately I have some very useful macros that I used in pyoro to simplify this:

;Use this instead of a label in any code that is to be copied somewhere else.
#define MAP(name,src,dest) name = ($+0 - src) + dest

;This is just a simple copy routine
#define COPY(src,dest,size) ld hl,src \ ld de,dest \ ld bc,size \ ldir

Here is it used in a useless example before and after:

BEFORE
call ClearScrn

ClearScrn:
inc a
dec hl
smc_Gray= $+1
ld a,%10101010
rrca
ld (smc_Gray),a
ret

After
;This should be in the beginning of the program
SMCram = appBackupScreen
COPY(SMCrom,SMCram,SMCromend-SMCrom)

;This is how you call the routine (same as before)
call ClearScrn

;This is the routine that will get copied to ram
SMCrom:
;Other SMC code can go here
MAP(ClearScrn,SMCrom,SMCram)
inc a
dec hl
MAP(smc_Gray,SMCrom,SMCram)+1
ld a,%10101010
rrca
ld (smc_Gray),a
ret
;The rest of your SMC goes here
SMCromend:


Oh, are they just simple non-executing data?  Much simpler!  You can create variables in ram instead of in the rom (as long as they fit there) by just defining them to be there.  If they need to start initialized with some value, just make sure you initialize it all at the beginning of the program.  I also have a macro for variables:

#define VAR(name,size) name: \ .org name+(size)

This creates a variable of any size at the current .org position.  I usually define them at the end of the program, but you can put them in the beginning too.

;Program goes here
ld   a,(timer)
ld   (score),hl
;End of program

;You can use any safe ram for this.  This is where the variables get stored.
.org appBackUpScreen

;Declare all variables and appropriate sizes
VAR(timer,1)
VAR(score,2)

;This allocates 1 byte to the timer variable and 2 bytes to the score variable.


Oh, are they just simple non-executing data?  Much simpler!  You can create variables in ram instead of in the rom (as long as they fit there) by just defining them to be there.  If they need to start initialized with some value, just make sure you initialize it all at the beginning of the program.  

Nice, it's working!
And when I edit the program, then re-send it to my calc, the scores won't disappear, which is great to! (else every time I'd release an improved version of my game, all scores/progress would be lost).
I don't really get how it works though, is it save?
Or do the variables easely get overwritten?

Ah, I suppose it doesn't matter.
It's working like a charm right now, so all is fine.
Now I just need to find out how to turn the programm into an app, which I'm sure google will help me with that  .

anyway, thank you for this.

Game is practically working (exept that it isn't because of the 8 kB limit).
All thats left is to work out the achievements/score system.
Game is nearly finished, but I'm still struggling with converting my prog to an app.
I found the Wabbitsign tool, but I must be doing something wrong, since i get a "source file open error" when I do what wabbitsign tells me:
It sayd I've got to:

Do the following at the command line to assemble your code into binary format and then sign.

   tasm -80 -i -b infile.z80 outfile.bin
   wabbit outfile.bin App.8xk

So I go to my c:\asm\tasm and there I type the first line (with infile and outfile filled in ofcourse), but then I get that "source file open error".

But first I must learn how to turn my program into an application, THEN i can use AppVars



Anyway, I'll struggle on and see where I strand, you've really been a big help Quigibo!

This is the line I've got in my batch script:

"C:\wabbitdirectory\rabbitsign" -g yourfile.bin

Yes, TASM and SPASM should be able to do this.  I have this line directly before the conversion in tasm:

"C:\tasmdirectory\tasm" -80 -i -b yourfile.z80 yourfile.bin

I attached the fully automated batch file I use, rename it .bat.  You'll have to change some of the directories to where you keep tasm and wabbitsign in.  When you click on the batch file, it searches its current directory, finds the file with a .z80 extension (you should only have 1 per directory, the rest should be .inc), copies some temporary files around needed for compiling, compiles it to an app, and then deletes the temporary files.  Also catches and displays errors.

I think spasm might be better for this, I know it comes with a lot of macros and things to make app compiling a lot easier.  You also need a special header for the app.