Routines
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60939: Calculate Attribute Cell Address
Used by the routines at Initialise_Display_And_Border and Adjust_Score_Field_Cursor.
Looks up a character index in the word table at 17920 to find its pixel row address, then converts that address to the corresponding attribute cell in the range 22528-23551 by shifting the screen row right by 3 and combining with 88. Called by Adjust_Score_Field_Cursor to position score entry highlight attributes.
Input
A Character index
Calculate_Attr_Cell_Address 60939 LD H,70 Look up the character index in the word table at 17920 and load the pixel row address into HL.
60941 LD L,A
60942 ADD HL,HL
60943 LD E,(HL)
60944 INC HL
60945 LD D,(HL)
60946 EX DE,HL
60947 LD A,H Convert the pixel row address to the attribute cell address in the range 22528-23551.
60948 RRCA
60949 RRCA
60950 RRCA
60951 AND 3
60953 OR 88
60955 LD H,A
60956 RET Return.
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