Mega Magazine 5/Mega_Magazine_05_19xx___nl_Side_B.atr/bigscrol.lzh/BIGDLI.ASM

Assembly Source File | 1988-09-01 | 2KB | 1 lines

DLINTERRUPT¢; POINT TO DLI¢     SEI¢     LDA #DLI&255¢     STA $200¢     LDA #DLI/256¢     STA $201¢     LDA #192      ; ACTIVATE¢     STA $D40E     ; DLI¢     CLI¢     RTS¢DLI¢; SAVE REGISTERS¢     PHA¢     TXA¢     PHA¢     TYA¢     PHA¢; MAKE TOP SCROLL COLOURS¢     LDY #0¢     LDX #255¢DOTOP¢     LDA TOPCOL,Y¢     STX $D40A¢     STA $D01A¢     LDA TOPTXT,Y¢     STA $D016¢     INY¢     CPY #31¢     BNE DOTOP¢; MAKE BIG SCROLLER MOVE AND COLOUR IT¢     LDY #0¢     INC OFFSET+1¢     INC OFFSET+1¢; UPDATE SINUS MOVEMENT¢     DEC SINPOINT¢     LDX SINPOINT¢     CPX #255¢     BNE DODLI¢     LDX #180¢     STX SINPOINT¢DODLI¢     TYA¢     CLC¢     ADC OFFSET+1¢     STX $D40A¢     STA $D012¢     EOR #255¢     STA $D014¢     AND #15¢     STA $D013¢     EOR #15¢     CLC¢     ADC #96¢     STA $D015¢¢; MAKE STARS SCROLL¢     LDA STARSCROLL,Y¢     CLC¢     ADC ST2,Y¢     STA STARSCROLL,Y¢     STA $D004¢     BCC NONEWSPEED¢; SET NEW SPEED¢     LDA 53770¢     AND #3¢     ADC #0¢     STA STARSCROLL,Y¢     STA ST2,Y¢NONEWSPEED¢     LDA 53770¢     STA $D019¢¢     LDA TABWAVE,X¢     SEC¢     SBC #38¢     STX $D40A¢     STA $D000¢     CLC¢     ADC #32¢     STA $D001¢     ADC #32¢     STA $D002¢     ADC #32¢     STA $D003¢; KEEP SINUS IN ORDER¢     INX¢     CPX #181¢     BNE KK2¢     LDX #0¢KK2¢     INY¢     INY¢     CPY #150¢     BNE DODLI¢; UPDATE BOTTOM SCROLL¢     STY $D40A     ; WSYNC¢     LDA HPOS+1¢     STA $D404¢; POINT TO CHARSET AT $8000¢     LDA #$80¢     STA $D409¢; MOVE PM'S OFF SCREEN¢     LDY #0¢     STY $D000¢     STY $D001¢     STY $D002¢     STY $D003¢     STY $D004¢; DO BOTTOM SCROLL COLOURS¢     LDX #255¢DOLOW¢     LDA BOTCOL,Y¢     STX $D40A¢     STA $D01A¢     LDA BOTTXT,Y¢     STA $D016¢     INY¢     CPY #26¢     BNE DOLOW¢¢     STY $D40A¢     LDA #0¢     STA $D01A¢; POINT TO CHARSET AT $7C00¢     LDA #$7C¢     STA $D409¢; COLOUR CREDITS¢     LDY #0¢     LDX #255¢DOCRED¢     TYA¢     CLC¢     ADC #112¢     STX $D40A¢     STA $D016¢; MAKE STARS SCROLL LOWER¢     LDA STARSCROLL,Y¢     CLC¢     ADC ST2,Y¢     STA STARSCROLL,Y¢     STA $D004¢     BCC NOLOWSPEED¢; SET NEW SPEED¢     LDA 53770¢     AND #3¢     ADC #0¢     STA STARSCROLL,Y¢     STA ST2,Y¢NOLOWSPEED¢     LDA 53770¢     STA $D019¢¢     INY¢     CPY #28¢     BNE DOCRED¢¢; RESTORE REGISTERS AND EXIT INTERRUPT¢     PLA¢     TAY¢     PLA¢     TAX¢     PLA¢     RTI¢