10 'Sosuu:Sieve of Eratosthenes
20 CLV:CLS
30 FOR C=0 TO 9:FOR B=0 TO 7
40 A=C*8+B
50 POKE #780+A,~PEEK(#180+A)
60 NEXT:NEXT
70 FOR I=0 TO 660 STEP 30
80 FOR J=1 TO 30
90 ?J%10;
100 NEXT
110 ?
120 NEXT
130 LC 0,0:?"*";
140 S=2
150 '@SLOOP
160 LC 0,23:?S;" É ÊÞ²½³";
170 M=1
180 '@NLOOP
190 M=M+1:N=S*M
200 IF N>690 GOTO 230
210 GSB 510:LC X,Y:?"*";
220 GOTO 180
230 '@NEND
240 GSB 530
250 IF S<346 GOTO 150
260 LC 0,23:?"           ";
270 N=2
280 '@VLOOP
290 V=0:GSB 580
300 IF BTN(LEFT) GSB 390
310 IF BTN(RIGHT) GSB 460
320 IF BTN(UP) GSB 370
330 IF BTN(DOWN) GSB 440
340 V=1:GSB 580
350 WAIT 10
360 GOTO 280
370 '@NUP
380 N=N-29
390 '@NLEFT
400 N=N-1:IF N<1 N=N+690
410 GSB 510
420 IF SCR(X,Y)=42 GOTO 390
430 RTN
440 '@NDOWN
450 N=N+29
460 '@NRIGHT
470 N=N+1:IF N>690 N=N-690
480 GSB 510
490 IF SCR(X,Y)=42 GOTO 460
500 RTN
510 '@XY
520 X=(N-1)%30:Y=(N-1)/30:RTN
530 '@SNEXT
540 S=S+1:IF S>345 RTN
550 N=S:GSB 510
560 IF SCR(X,Y)!=42 RTN
570 GOTO 530
580 '@VSUB
590 GSB 510
600 LC X,Y:?CHR$(48+V*192+N%10)
610 LC 0,23:?N;"  ";
620 RTN