Demo mode starts immediately on program start

$1547 after demo player dies
9 bytes available

$9E8 after user hits any key in demo mode
6 bytes available

$09E8: 20F2098D47.. -> AD88C06CFCFF
$1547: 20A61120BF12 -> AD88C06CFCFF
$6B22: 30 -> 00 to disable sound
$084C: 20 -> 00 to disable cassette sound
