Routines
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57773: Copy Attributes To Screen
Used by the routine at CopyBuffersToScreen.
Copies the attributes of the attribute buffer onto the screen, in the same way as CopyPixelsToScreen. The buffer holds 14 rows of 24 bytes, and the top row of the buffer is the bottom row of the playing area.
Point the stack at the last row of attributes.
CopyAttributesToScreen 57773 LD (48046),SP Save the stack pointer, point it at the end of the last row of attributes of the playing area, count 14 rows, and point HL at the end of the first row of the buffer.
57777 LD SP,23037
57780 LD B,14
57782 LD HL,61531
Copy a row and step up the screen.
CopyAttributesToScreen_Row 57785 LD D,(HL) Copy the last twenty bytes of the row from the buffer onto the screen, two at a time.
57786 DEC HL
57787 LD E,(HL)
57788 DEC HL
57789 PUSH DE
57790 LD D,(HL)
57791 DEC HL
57792 LD E,(HL)
57793 DEC HL
57794 PUSH DE
57795 LD D,(HL)
57796 DEC HL
57797 LD E,(HL)
57798 DEC HL
57799 PUSH DE
57800 LD D,(HL)
57801 DEC HL
57802 LD E,(HL)
57803 DEC HL
57804 PUSH DE
57805 LD D,(HL)
57806 DEC HL
57807 LD E,(HL)
57808 DEC HL
57809 PUSH DE
57810 LD D,(HL)
57811 DEC HL
57812 LD E,(HL)
57813 DEC HL
57814 PUSH DE
57815 LD D,(HL)
57816 DEC HL
57817 LD E,(HL)
57818 DEC HL
57819 PUSH DE
57820 LD D,(HL)
57821 DEC HL
57822 LD E,(HL)
57823 DEC HL
57824 PUSH DE
57825 LD D,(HL)
57826 DEC HL
57827 LD E,(HL)
57828 DEC HL
57829 PUSH DE
57830 LD D,(HL)
57831 DEC HL
57832 LD E,(HL)
57833 DEC HL
57834 PUSH DE
57835 LD D,(HL) Copy the first two bytes of the row onto the screen.
57836 DEC HL
57837 LD E,(HL)
57838 PUSH DE
57839 EX DE,HL Keep the buffer address in DE.
57840 LD HL,65526 Move up one row of attributes on the screen.
57843 ADD HL,SP
57844 LD SP,HL
57845 LD HL,45 Move on to the end of the next row of the buffer.
57848 ADD HL,DE
57849 DJNZ CopyAttributesToScreen_Row Loop back until all of the rows have been copied.
57851 LD SP,(48046) Get the stack pointer back and return.
57855 RET
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