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Elite on the BBC Micro and NES

Drawing the screen: DOVDU19

[BBC Master version]

Name: DOVDU19 [Show more] Type: Subroutine Category: Drawing the screen Summary: Change the mode 1 palette
Context: See this subroutine in context in the source code Variations: See code variations for this subroutine in the different versions References: This subroutine is called as follows: * HALL calls DOVDU19 * LOOK1 calls DOVDU19 * TITLE calls DOVDU19 * TRADEMODE calls DOVDU19 * TT22 calls DOVDU19 * TT23 calls DOVDU19

This routine updates the VNT3+1 location in the IRQ1 handler to change the palette that's applied to the top part of the screen (the four-colour mode 1 part). The parameter is the offset within the TVT3 palette block of the desired palette.
Arguments: A The offset within the TVT3 table of palettes: * 0 = Yellow, red, cyan palette (space view) * 16 = Yellow, red, white palette (charts) * 32 = Yellow, white, cyan palette (title screen) * 48 = Yellow, magenta, white palette (trading)
.DOVDU19 STA VNT3+1 \ Store the new colour in VNT3+1, in the IRQ1 routine, \ which modifies which TVT3 palette block gets applied \ to the mode 1 part of the screen RTS \ Return from the subroutine