1000 REM ONE-D MAP SEARCH (With Sound)
1100 SND% = 1                   'Turn sound on

2310    IF SND% = 1 THEN GOSUB 3500     'Produce sound

2490 Q$ = INKEY$: IF LEN(Q$) THEN GOSUB 3600        'Respond to user command

3500 REM Produce sound
3510 FREQ% = 220 * 2 ^ (CINT(36 * (XNEW - XL) / (XH - XL)) / 12)
3520 DUR = 1
3540 SOUND FREQ%, DUR: IF PLAY(0) THEN PLAY "MF"
3550 RETURN

3600 REM Respond to user command
3610 T% = 0
3630 IF ASC(Q$) > 96 THEN Q$ = CHR$(ASC(Q$) - 32)
3770 IF Q$ = "S" THEN SND% = (SND% + 1) MOD 2: T% = 3
3800 RETURN