.nolist
#include "ti83plus.inc"
.list
.org userMem-2
        .db 0BBh,6Dh
        ld hl,sDump
        rst 20h
        bcall(_chkFindSym)
        ret c
        ld a,b
        or a
        ret nz
        push de
        bcall(_runIndicOff)
        bcall(_clrLCDFull)
        bcall(_homeUp)
        ld hl,sConfirm
        bcall(_PutS)
        bcall(_getKey)
        bcall(_runIndicOn)
        bcall(_newLine)
        pop de
        cp kCapY
        ret nz
        inc de
        inc de
        push de
        call UnlockFlash
        ld a,7Eh
        call translatePage
        ld hl,4000h
        bcall(_EraseFlash)
        ld a,7Eh
        call translatePage
        ld hl,6000h
        bcall(_EraseFlash)
        ld a,7Eh
        call translatePage
        ld de,4000h
        ld bc,4000h
        pop hl
        bcall(8087h) ;_WriteFlashUnsafe
        ld hl,sDone
        bcall(_PutS)
        bcall(_newLine)
        ret
sDump:  .db AppVarObj,"CERTIMG",0
sConfirm:
        .db "Press           "
        .db LlBrack,"ALPHA]+",LlBrack,"Y] to  "
        .db "confirm writing "
        .db "or any other key"
        .db "to cancel",0CEh,0
sDone:  .db "CERTIMG written",0

UnlockFlash:
;Unlocks Flash protection.
;Destroys: appBackUpScreen
;          pagedCount
;          pagedGetPtr
;          arcInfo
;          iMathPtr5
;          pagedBuf
;          ramCode
        in a,(6)
        push af
        ld a,7Bh
        call translatePage
        out (6),a
        ld hl,5092h
        ld e,(hl)
        inc hl
        ld d,(hl)
        inc hl
        ld a,(hl)
        call translatePage
        out (6),a
        ex de,hl
        ld a,0CCh
        ld bc,0FFFFh
        cpir
        ld e,(hl)
        inc hl
        ld d,(hl)
        push de
        pop ix
        ld hl,9898h
        ld (hl),0C3h
        inc hl
        ld (hl),returnPoint & 11111111b
        inc hl
        ld (hl),returnPoint >> 8
        ld hl,pagedBuf
        ld (hl),98h
        ld de,pagedBuf+1
        ld bc,49
        ldir
        ld (iMathPtr5),sp
        ld hl,(iMathPtr5)
        ld de,9A00h
        ld bc,50
        ldir   
        ld de,(iMathPtr5)
        ld hl,-16
        add hl,de
        ld (iMathPtr5),hl
        ld iy,0056h-25h
        ld a,50
        ld (pagedCount),a
        ld a,8
        ld (arcInfo),a
        jp (ix)
translatePage:
        ld b,a
        in a,(2)
        and 80h
        jr z,_is83P
        in a,(21h)
        and 3
        ld a,b
        ret nz
        and 3Fh
        ret
_is83P: ld a,b
        and 1Fh
        ret
returnPoint:
        ld iy,flags
        ld hl,(iMathPtr5)
        ld de,16
        add hl,de
        ld sp,hl
        ex de,hl
        ld hl,9A00h
        ld bc,50
        ldir
        pop af
        out (6),a
        ret
.end
end