10 REM Test speaker via OUT (PIT + PPI)
20 OUT &H43, &HB6
30 OUT &H42, &HD3
40 OUT &H42, &H04
50 OUT &H61, INP(&H61) OR 3
60 REM Speaker on briefly
70 OUT &H61, INP(&H61) AND &HFC
80 PRINT "SPEAKER OK"
90 SYSTEM