1000 GRAPHICS 1+16:POKE 752,1:PRINT " "
1010 DIM DLI$(35)
1020 DL=PEEK(560)+PEEK(561)*256

2000 REM read in assembly code to modify graphics
2010 FOR I=1 TO 35:READ X:DLI$(I)=CHR$(X):NEXT I
2020 DATA 72,152,72,172,0,4,185,2,4,141,10,212
2030 DATA 141,24,208,238,0,4,173,0,4,205,1,4
2040 DATA 144,5,169,0,141,0,4,104,168,104,64

3000 REM modify display list for interrupt
3010 FOR I=2 TO 3:POKE DL+I,PEEK(DL+I)+128:NEXT I
3020 FOR I=6 TO 27:POKE DL+I,PEEK(DL+I)+128:NEXT I

4000 REM point to DLI in memory and enable interrupt
4010 DLIADR=ADR(DLI$)
4020 DLIHI=INT(DLIADR/256):DLILO=(DLIADR-DLIHI*256)
4030 POKE 512,DLILO:POKE 513,DLIHI
4040 POKE 54286,128+64

5000 REM read background color data to page 4
5010 POKE 1024,0:POKE 1025,24
5020 FOR I=0 TO 23:READ X:POKE 1026+I,X:NEXT I
5030 DATA 112,112,112,112,112,112,114,114,114,114,114,114
5040 DATA 116,116,116,116,116,116,118,118,118,118,118,118

10000 GOTO 10000