Killing The Mirage Password

[Jeffrey]

I am making a program that will automatically delete the Mirage password appvar when the memory key is pressed. I have made a test program that should do this when the "2" key is pressed. It always errors up and says MEMORY error when I run it.

The bold section can run by itself and works fine, but when inserted into the program, it screws up. The underlined "_arc_unarc" is the problem, I believe.


#include "ti83plus.inc";File needed to access system routines
.org userMem-2 ;Define where to start in memory
.db $BB,$6D ;AsmPrgm instruction
_setrawkeyhook   .equ 4f66h
_clearrawkeyhook .equ 4f6fh

#define hooksize end_of_hook-the_hook
#define offset 523h-endmain+usermem


ld hl, appbackupscreen
ld de, the_hook
in a,(6)
bcall(_setrawkeyhook)
ex de,hl
ld bc, hooksize
ldir
jp quit


the_hook:
.db 83h;Required byte
cp k2
jp z,implement
ret

implement:

ld hl,miragevar
rst20h
bcall(_ChkFindSym)
ld a,b
cp 0
jp z,goahead
ld hl,miragevar
rst 20h
errhandon(basicErrHandler)
bcall(_cleanall)
bcall(_arc_unarc)
goahead:
ld hl,miragevar
rst 20h
bcall(_ChkFindSym)
jp c,gone
bcall(_delvar)
errhandoff()
ret
end_of_hook

basicErrHandler:
or a;you must have this
ret

miragevar:
.db AppVarObj,"MirageOS",0

quit:
bjump(_JForceCmdNoChar)
ret


gone:
 
ret    ;Exit program
.end    ;End of code


Any ideas?

[David]

Yes, I have some suggestions for you. Your problem is that you're loading the appvar name into OP1 from the wrong location. Since you have an .org UserMem, MirageAppvar will point to usermem, but it should point to appbackupscreen instead as the hook code resides there. Solution is to use the syntax ld hl,mirageappvar-offset, where offset simply is the distance in memory between usermem and appbackupscreen. This offset is defined in the source code, but I don't know if it's being calculated since there's no endmain label.
One more thing, bjump(_jforcecmdnochar) is for APPS only. TI clearly discourages asm programs from using it to exit. Use ret instead. I haven't tested this version, but I hope it will work :)

[JoeImp]

hehe I made a program that deleted the mirageOS appvar a while ago. You just ran it with asm(prgmKillMir or whatever, no pressing a button. I dont know if I still have it tho

Imp

[Jeffrey]

I have already done one like that, where you dont need to press a button, but this one is designed for classroom use, where the program that deletes the appvar only needs to be sent once, and automatically deletes the password, no need to manually do it.