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⌂ ∞ ▽ Elite on the BBC Micro and NES

Missions: PAS1_b0

[NES version, Bank 7]

       Name: PAS1_b0                                                 [Show more]
       Type: Subroutine
   Category: Missions
    Summary: Call the PAS1 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:
             * PAUSE calls PAS1_b0




.PAS1_b0

 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

 JSR PAS1               ; Call PAS1, 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