A654: C0 -> D0 to disable sound
A665: C0 -> D0 to disable sound
9494: C0 -> D0 to disable sound
ABD9: C0 -> D0 to disable sound
1F36: C0 -> D0 to disable sound
1F3E: C0 -> D0 to disable sound
9998: C0 -> D0 to disable sound


A7B4 jmp a686 - end of demo cycle


a253 jmp 100 to exit on keypress

