Routines
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63242: Colour-Cycle Main Menu Logo
Used by the routines at MainMenu, MainMenu_SelectOptions and Print_ControlKeyLabels.
Cycle attributes across the eight logo cells at Table_MainMenuLogoAttributes. Picks a fresh paper value via PseudoRandom (avoiding a repeat of the scratch byte at Font_MainMenuLogo), then paints a 6×9 attribute block at each cell. Used after Draw_MainMenuLogo and as a menu acknowledge flash from MainMenu_SelectOptions.
logo-cycle
Walk all eight logo cells with a new random attribute.
ColourCycle_MainMenuLogo 63242 LD IX,63174 Point IX at Table_MainMenuLogoAttributes.
63246 LD D,0 Clear D (row-step high byte stays 0).
63248 LD B,8 There are 8 logo cells to recolour.
Recolour one of the eight logo cells with a fresh random paper attribute.
ColourCycle_MainMenuLogo_CellLoop 63250 PUSH BC Stash BC on the stack.
63251 LD HL,63296 Point HL at the logo-font scratch byte.
63254 LD A,5 Load A with 5 (random range for the attribute pick).
Pick a paper value that differs from the previous pick at Font_MainMenuLogo.
ColourCycle_MainMenuLogo_PickAttr 63256 CALL PseudoRandom Call PseudoRandom to pick a pseudo-random value.
63259 CP (HL) Does it match the previous pick at Font_MainMenuLogo? If so, jump to ColourCycle_MainMenuLogo_PickAttr to pick again.
63260 JR Z,ColourCycle_MainMenuLogo_PickAttr
63262 LD (HL),A Store the new pick at Font_MainMenuLogo.
63263 ADD A,2 A+=2.
63265 ADD A,A Multiply by 8 to form a paper attribute.
63266 ADD A,A
63267 ADD A,A
63268 LD L,(IX+0) Fetch this cell's attribute address into HL.
63271 LD H,(IX+1)
63274 LD C,6 There are 6 attribute rows to paint.
Paint one attribute row of the 6×9 logo cell.
ColourCycle_MainMenuLogo_RowLoop 63276 LD B,9 There are 9 attribute cells in a logo row.
Write one attribute cell of the colour-cycled logo row.
ColourCycle_MainMenuLogo_ColLoop 63278 LD (HL),A Write the attribute at HL.
63279 INC HL Advance along the attribute row.
63280 DJNZ ColourCycle_MainMenuLogo_ColLoop Decrease the column counter and jump to ColourCycle_MainMenuLogo_ColLoop while columns remain.
63282 LD E,23 Load E with 23 (bytes from row end to the next logo row).
63284 ADD HL,DE Step HL onto the next attribute row.
63285 DEC C Decrease the row counter.
63286 JR NZ,ColourCycle_MainMenuLogo_RowLoop Jump to ColourCycle_MainMenuLogo_RowLoop while rows remain.
63288 INC IX Move IX to the next attribute address in the table.
63290 INC IX
63292 POP BC Restore BC from the stack.
63293 DJNZ ColourCycle_MainMenuLogo_CellLoop Decrease the cell counter and jump to ColourCycle_MainMenuLogo_CellLoop while cells remain.
63295 RET Return.
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