Routines
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58485: Set Home To Default Attributes
Used by the routine at 57069.
Home_DefaultAttributes 58485 LD DE,22562 DE=22562 (attribute buffer location).
58488 LD HL,58542 HL=HomeAttributes.
The home block is 4x4 (4 rows of 4 bytes) but not all of it cycles attributes. Only 3x4 is used here.
58491 LD B,4 Set a counter in B for 4 rows.
Home_DefaultAttributes_Loop 58493 PUSH BC Stash the row counter on the stack.
58494 LD BC,3 Copy 0003 bytes from the attribute buffer to HomeAttributes.
58497 LDIR
One full row is 32 bytes, so this is 3 bytes less than one row. Hence this moves down one row, but back to the start of the line.
58499 EX DE,HL Add 0029 to the attribute buffer position.
58500 LD BC,29
58503 ADD HL,BC
58504 EX DE,HL
58505 POP BC Restore the row counter from the stack.
58506 DJNZ Home_DefaultAttributes_Loop Decrease the row counter by one and loop back to Home_DefaultAttributes_Loop until all the rows have been updated.
58508 RET Return.
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