Drawing the screen: SetLinePatterns_b3

       Name: SetLinePatterns_b3                                      [Show more]
       Type: Subroutine
   Category: Drawing the screen
    Summary: Call the SetLinePatterns routine in ROM bank 3
  Deep dive: Splitting NES Elite across multiple ROM banks
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * ShowScrollText calls SetLinePatterns_b3
             * TT66 calls SetLinePatterns_b3


.SetLinePatterns_b3

 LDA currentBank        ; If ROM bank 3 is already paged into memory, jump to
 CMP #3                 ; bank10
 BEQ bank10

 PHA                    ; Otherwise store the current bank number on the stack

 LDA #3                 ; Page ROM bank 3 into memory at $8000
 JSR SetBank

 JSR SetLinePatterns    ; Call SetLinePatterns, now that it is paged into memory

 JMP ResetBank          ; Fetch the previous ROM bank number from the stack and
                        ; page that bank back into memory at $8000, returning
                        ; from the subroutine using a tail call

.bank10

 JMP SetLinePatterns    ; Call SetLinePatterns, which is already paged into
                        ; memory, and return from the subroutine using a tail
                        ; call