Routines
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33115: Clear the menu screen
Used by the routines at 32825, 33021 and 33069.
Input
A Colour/attribute value (second routine only)
Two routines used in both menus - one routine to clear screen pixels, the second to clear the screen colours.
Clear the screen (pixels):
33115 LD HL,16384 Top left of screen display
33118 LD DE,6144 Number of bytes to clear
33121 LD (HL),0 Clear screen pixels
33123 INC HL Move to next screen byte position
33124 DEC DE Decrement byte counter
33125 LD A,E
33126 OR D
33127 JR NZ,33121 Keep clearing until counter = 0
33129 RET
Clear the screen (colours):
33130 LD HL,22528 Top left of (attribute) screen display
33133 LD DE,768 Number of bytes
33136 LD C,A Retrieve attribute/colour value to use
33137 LD (HL),C Put colour on screen
33138 INC HL Advance to next screen square
33139 DEC DE Decrement byte counter
33140 LD A,E
33141 OR D
33142 JR NZ,33137 Keep colouring until counter = 0
33144 RET
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