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⌂ ∞ Elite on the BBC Micro and NES

PPU: UpdateHangarView

[NES version, Bank 7]

       Name: UpdateHangarView                                        [Show more]
       Type: Subroutine
   Category: PPU
    Summary: Update the hangar view on-screen by sending the data to the PPU,
             either immediately or during VBlank
  Deep dive: Views and view types in NES Elite

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * HALL calls UpdateHangarView




.UpdateHangarView

 LDA #0                 ; Page ROM bank 0 into memory at $8000 (this isn't
 JSR SetBank            ; strictly necessarily as this routine gets jumped to
                        ; from the end of the HALL routine in bank 1, which
                        ; itself is only called via HALL_b1, so the latter will
                        ; revert to bank 0 following the RTS below and none of
                        ; the following calls are to bank 0)

 JSR CopyNameBuffer0To1 ; Copy the contents of nametable buffer 0 to nametable
                        ; buffer

 JSR UpdateScreen       ; Update the screen by sending data to the PPU, either
                        ; immediately or during VBlank, depending on whether
                        ; the screen is visible

 LDX #1                 ; Hide bitplane 1, so:
 STX hiddenBitplane     ;
                        ;   * Colour %01 (1) is the visible colour (cyan)
                        ;   * Colour %10 (2) is the hidden colour (black)

 RTS                    ; Return from the subroutine