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⌂ ∞ Elite on the BBC Micro and NES

Icon bar: CheckForPause_b0

[NES version, Bank 7]

       Name: CheckForPause_b0                                        [Show more]
       Type: Subroutine
   Category: Icon bar
    Summary: Call the CheckForPause routine in ROM bank 0
  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:
             * CheckSaveLoadBar calls CheckForPause_b0
             * DrawScrollFrames calls CheckForPause_b0




 Returns:

   N, Z flags           Set according to the value of A passed to the routine



.CheckForPause_b0

 STA storeA             ; Store the value of A so we can retrieve it below

 LDA currentBank        ; Fetch the number of the ROM bank that is currently
 PHA                    ; paged into memory at $8000 and store it on the stack

 LDA #0                 ; Page ROM bank 0 into memory at $8000
 JSR SetBank

 LDA storeA             ; Restore the value of A that we stored above

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

 JMP ResetBankP         ; Jump to ResetBankP to retrieve the bank number we
                        ; stored above, page it back into memory and set the
                        ; processor flags according to the value of A, returning
                        ; from the subroutine using a tail call