To program the Apple II in Basic you need to be looking at a screen with the ] prompt blinking on it. From there you simply type the line number and whatever basic programming the line contains. Unfortunately the Apple II doesn't do automatic line numbering in Basic, to get something like that you'll need something like Beagle Bros Program Writer program or one of several other programs that will help you write a Basic program.

As far as code to access the drives hopefully someone else on the forum who knows more than I do about programming the Apple II will chime in.

Hope this hels,

Dean