%X;SCREEN SCROLLER ASSEMBLY LISTINGX; (C) 1984 JEFF BRENNER( 7;SETUP2Q><P=&X;---------------------------------A&X;Lines 70-100 store the address ofB!X;the scrolling routine in theC"X;deferred VB interrupt vector.D&X;---------------------------------FQ>STARTPP$ZQ>STARTdP%nQ>@xP;;Re-enable VB:;;Return to BASIC START6-Q;;$CE=timing cntr#δR;;$CE=delay?HRETURN;;If not, end.Q>P,Q;;# of scan lines;scrolled.O>PR>EUP;Before 16 scan;lines, text must;be moved up.P" HRETURN, UPQ>6P;;Reset vertical7;scroll register@=P;;Reset scroll cnt0324 ;-------------------------------EX;Lines 330-450 move entireF X;display upwards by one lineGX;of text (20 bytes).H$X;-------------------------------J,TQX^O>hPrQY|O>P͐%> LOOPQ@7P@X73)> HLOOP RETURN87?7>79;Return from VBI