Commodore VIC-20 User Manual page 202

188
The VIC 20 User Guide
lee OOSUB 413131313
21313 CR=15
31313 CC=2
41313 POKE
SB+CC+CR~22,e
51313 POKE 37139,128
1131313 IF xs()e AND TI)XT THEN CC=CC+SGN(XS):XT=TI+6e/ABS(XS)
111313 IF Ys()e AND TI)YT THEN CR=CR+SGN(YS):YT=TI+6e/ABS(YS)
11213 IF Cc(e OR CC)21 THEN 4131313
11413 IF CR(e OR CR)22 THEN 413013
11513 POKE BA, 32
121313 BA=SB+CC+CR*22
13013 TO=PEEK(BA)
14130 IF TO()0 AND TO()32 THEN 51300
151313 POKE BA,0
161313 IF TT)TITHEN 113813
171313 TT"'TI+313
17513 POKEV2,129
1800 OOSUB 63131313
18513 POKEV2,e
19013 XS=XS+XI:Y$=YS+YI
213013 00TOlee0
4131313 IF Cc(e THEN CC=13
411313 IF CC)21THEN CC=21
421313 IF CR(0 THEN CR=0
4300 IF CR}22THEN CR=22
451313 BA=SB+CC+CR*22
5131313 POKE BA,e
5100 FOR I=lT03513:NEXTI
521313 POKE BA,32
531313 FOR I=lT03513:NEXTI
54130 OETA$: IFA$() " "THENlee
551313 00T050130
413131313 PRINT":,]";
41313113 SB=256*PEEK(648)
41313213 CB=38413e
41313313 IF SB(>76813THENCB=37888
41131313 REMFORI=SBTOSB+5eS:POKEI,32:NEXTI
42131313 FORI=CBTOCB+5e5:POKEI,6:NEXTI
51313213 xs=e:YS=0:XT=13:YT=e
5130313 RS=37152:RD=37154:LS=37137:V2=36875
51313413
LMr.=16:RMr.=128:UM~=4:DMr.=8:ML~=127
51313513
LM~=16:RM~=128:UMr.=4:DM~=8:ML~=127
51313613 POKE36878,15
5131130 PR I NT"
Ei iIllllliIl!IIIII!!I!I!I!I!111 i!IIiIB" ;
5131213 PRINT". _ .";
5131413 PRINT". . .
I";
513160 PRINT"
iI • . ,
I";
FIGURE
6-5.
Racetrack program
(continued)