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⌂ ∞ Elite on the BBC Micro and NES

Text: TT27_b2

[NES version, Bank 7]

       Name: TT27_b2                                                 [Show more]
       Type: Subroutine
   Category: Text
    Summary: Call the TT27 routine in ROM bank 2
  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:
             * cpl calls TT27_b2
             * csh calls TT27_b2
             * EQSHP calls TT27_b2
             * mes9 calls TT27_b2
             * MESS calls TT27_b2
             * NLIN3 calls TT27_b2
             * plf calls TT27_b2
             * PrintEquipment calls TT27_b2
             * PrintLaserView calls TT27_b2
             * PrintSaveHeader calls TT27_b2
             * PrintSpaceAndToken calls TT27_b2
             * PrintSpacedHyphen calls TT27_b2
             * PrintSpaceViewName calls TT27_b2
             * PrintTokenAndColon calls TT27_b2
             * PrintTokenCrTab calls TT27_b2
             * prq calls TT27_b2
             * spc calls TT27_b2
             * STATUS calls TT27_b2
             * TT147 calls TT27_b2
             * TT151 calls TT27_b2
             * TT162 calls TT27_b2
             * TT210 calls TT27_b2
             * TT213 calls TT27_b2
             * TT25 calls TT27_b2
             * TT60 calls TT27_b2
             * TT66 calls TT27_b2
             * TT67 calls TT27_b2
             * TT68 calls TT27_b2
             * TT70 calls TT27_b2
             * TT73 calls TT27_b2




.TT27_b2

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

 LDA currentBank        ; If ROM bank 2 is already paged into memory, jump to
 CMP #2                 ; bank24
 BEQ bank24

 PHA                    ; Otherwise store the current bank number on the stack

 LDA #2                 ; Page ROM bank 2 into memory at $8000
 JSR SetBank

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

 JSR TT27               ; Call TT27, 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

.bank24

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

 JMP TT27               ; Call TT27, which is already paged into memory, and
                        ; return from the subroutine using a tail call