Listing of file='SCROLL.MAC;02' on disk='vmedia/forutil_1-sector.ccvf'
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ; SCROLL PATCH ; ; CALLING SEQUENCE: ; CALL SCROLL(X,Y,H,W,C) ; ALL VALUES ARE BYTES ; SEE COMPUCOLOR SCROLL PATCH FOR DESCRIPTIONS ; ; RETURNS: ; NOTHING ; ENTRY SCROLL EXTRN XYADDR SCROLL: PUSH D PUSH H LDAX B MOV E,A INX B LDAX B MOV D,A INX B LDAX D DCR A STA NOLINS LDAX B MOV E,A INX B LDAX B MOV D,A INX B LDAX D MOV H,A MVI A,128 SUB H SUB H STA ENDADR XRA A STA DOUBLE MOV A,H ADD H STA WIDTH LDAX B MOV E,A INX B LDAX B MOV D,A LDAX D ORA A JNZ SC05 MVI A,23H ;'INX H' STA DOUBLE MOV A,H STA WIDTH SC05: POP H POP D MOV B,M XCHG MOV C,M CALL XYADDR SHLD STADR DB 21H ;LXI H,STADR STADR: DW 7000H DB 06H ;MVI B,NOLINS NOLINS: DB 4 SC10: DB 0EH ;MVI C,WIDTH WIDTH: DB 128 SC20: LXI D,128 DAD D MOV A,M LXI D,-128 DAD D MOV M,A INX H DOUBLE: NOP ;POKE AN 'INX H' IN HERE DCR C JNZ SC20 DB 11H ;LXI D,ENDADR ENDADR: DW 08H DAD D DCR B JNZ SC10 RET END