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Routines |
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Used by the routine at E396.
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| E66A | LD DE,$5822 | DE=5822 (attribute buffer location). | ||
| E66D | LD HL,$E6A3 | HL=HomeAttributes. | ||
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The home block is 04x04 (04 rows of 04 bytes) but not all of it cycles attributes. Only 03x04 is used here.
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| E670 | LD B,$04 | Set a counter in B for 04 rows. | ||
| E672 | PUSH BC | Stash the row counter on the stack. | ||
| E673 | LD BC,$0003 | Copy 0003 bytes from the attribute buffer to HomeAttributes. | ||
| E676 | LDIR | |||
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One full row is 20 bytes, so this is 03 bytes less than one row. Hence this moves down one row, but back to the start of the line.
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| E678 | EX DE,HL | Add 001D to the attribute buffer position. | ||
| E679 | LD BC,$001D | |||
| E67C | ADD HL,BC | |||
| E67D | EX DE,HL | |||
| E67E | POP BC | Restore the row counter from the stack. | ||
| E67F | DJNZ $E672 | Decrease the row counter by one and loop back to E672 until all the rows have been updated. | ||
| E681 | RET | Return. | ||
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