A tft addin for pbp3

[richard]

having an issue here with a usercmd macro overwriting an array boundary and I'm at a loss to understand what I'm doing wrong ,
attached is a safer version of the touch screen addin.

problem is , lets say I have defined number_of_buttons con 9
vars are defined by button_Taddr VAR byte[number_of_buttons*3]

by my count that's 27 bytes

I usercmd a button the nineth button

MAKEBUTTON 34,216,8,40
in the macro k=Button*3 which should be 24
so

movlw 0
movwf _button_Taddr +k
movwf _button_Taddr +k+1
movwf _button_Taddr +k+2
should place 0 into button_Taddr[24-26]
but something else gets clobbered instead , buttons 0-7 seem ok but I might be wrong

  
MAKEBUTTON?CCCC  macro X0in ,Y0in ,Button ,Szin     ;sqr button no text
k=Button*3   ; 
j=Button*2    ;1 WORD  PER BUTTON
i=Button*6    ;3 WORDS PER BUTTON
    
    if Button <8
    bcf _button_action ,Button
    bcf _button_rpt ,Button
    bcf _button_set ,Button
    else
    bcf _button_action+1 ,Button-8
    bcf _button_rpt+1 ,Button-8
    bcf _button_set+1 ,Button-8
    endif
    MOVE?CW  Szin ,_button_xsize+ j
    MOVE?CW  Szin ,_button_ysize+ j
    MOVE?CB  0  , _BUTTON_STATE + Button
;    movlw   0
;    movwf   _button_Taddr +k 
;    movwf   _button_Taddr +k+1
;    movwf   _button_Taddr +k+2
    MOVE?CW  0  ,button_count +i
    MOVE?CW  X0in ,button_X  +i
    MOVE?CW  Y0in ,button_Y  +i
    MOVE?CW  0, _button_Tsize +  j   
  endm