; This is an example of a Plug-In file that captures whatever is on the
; screen to the GRAPH screen every time [GRAPH] is pressed.  Note that
; plug-ins are only called during GET_KEY loops so you can only grab images
; on the screen when the program requests a key press.
; Compile with TASM and use "MAKESN.EXE GRAB START END"

#include "TI-85.H"
.org 0
.db 0           ; Z-Terminated title of our program
                ; I didn't add a title to conserve space.
; A Plug-In file has took hook on to SuperNova so that it will be called
; during GET_KEY calls.  To do this a Plug-In uses the startup and shutdown
; string characteristics to hook and unhook itself from SuperNova.
        LD_PLUGIN(oldhandler,customroutine)
                                ; Load Plug-In system
        ret                     ; Return to normal operation

; This is the plug-in routine for GRAB
; This routine will be called everytime GET_KEY is called.
customroutine:
        push hl                 ; Make sure to save all registers!
        push bc                     
        push de                     
        push af                     
        cp $2F                  ; [GRAPH] = Capture Screen
        jr nz,return
        ld hl,VIDEO_MEM
        ld de,GRAPH_MEM
        ld bc,1024
        ldir
return:
        pop af                  ; Restore all Registers!
        pop de
        pop bc
        pop hl

oldhandler:
        CALL ERROR_CALL         ; This is needed so that other plugins
                                ; will be called after this one is done.

 ; YOU MUST put this here, otherwise other previously loaded Plug-Ins
 ; WILL NOT BE CALLED by SuperNova.

        ret                     ; Jump back to SN

.end