Ah, yes doing a step on joystick input would be easy to add. Let me have a look into that. Usually the music driver is running off the system interrupt. I'll have to double check but I think as I don't set the timer speed it'll default to 60fps on both PAL & NTSC systems. The tempo counts X ticks and then moves to the next step. Note lengths are dependent on the oscillator's gate being switched on or off on a step. As it's feeding data into the sound chip registers directly all the settings for a channel can be independent of each other. The downside with this editor is registers can only be set to a fixed value once per step (the left side of the screen) , but their values can be altered per tick using addition/subtraction on the right side of the screen.