;-------------------------------
; #JSRBB03
; boot1 calls $BB03 for a self-
; decrypting nibble check which
; continues to $B793 on success
; e.g. Classifying Animals with
; Backbones, EduCalc
;-------------------------------
_jsrbb03
         lda   gIsBoot0   ; if DOS 3.3 boot0 loader
         bne   jsrbb03_exit
         lda   gIsBoot1   ; and DOS 3.3 boot1 loader
         bne   jsrbb03_exit
         lda   #$01
         ldx   #$38
         ldy   #$03
         jsr   compare    ; and T00,S01,$38 ==
         !byte $20,03,$BB
         bcs   jsrbb03_exit
         lda   #$05
         ldx   #$03
         ldy   #$25
         jsr   compare    ; and T00,S05,$03 ==
         !byte $4E,06,$BB,$71,$6E
         !byte $0A,$BB,$40,$27,$6E,$0F,$BB,$DD
         !byte $1B,$BB,$6E,$15,$BB,$DC,$1E,$BB
         !byte $6E,$25,$BB,$72,00,$BB,$B3,00
         !byte $B8,$99,00,$BB,$C8,$A0,$F4,$B0
         bcs   jsrbb03_exit
         lda   #s_jsrbb03
         jsr   PrintByID
         lda   #$05
         ldx   #$03
         ldy   #$09
         jsr   modify     ; then set T00,S05,$03 =
         !byte $A9,$B5,$48,$A9,$18,$48,$4C,$93,$B7
jsrbb03_exit