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⌂ ∞ Elite on the BBC Micro and NES

Utility routines: ResetBankP

[NES version, Bank 7]

       Name: ResetBankP                                              [Show more]
       Type: Subroutine
   Category: Utility routines
    Summary: Page a specified bank into memory at $8000 while preserving the
             value of A and the processor flags
  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:
             * CheckForPause_b0 calls ResetBankP
             * CheckPauseButton calls via RTS4
             * ChooseMusic_b6 calls via RTS4




 Arguments:

   Stack                The number of the bank to page into memory at $8000



 Other entry points:

   RTS4                 Contains an RTS



.ResetBankP

 PLA                    ; Fetch the ROM bank number from the stack

 PHP                    ; Store the processor flags on the stack so we can
                        ; retrieve them below

 JSR SetBank            ; Page bank A into memory at $8000

 PLP                    ; Restore the processor flags, so we return the correct
                        ; Z and N flags for the value of A

.RTS4

 RTS                    ; Return from the subroutine