Can a regular disk be punched to make hard sectored
disc?
It should be possible. One thing I intent to try sometime is to strip
down an old half-height direct-drive 5.25" floppy drive and mount a
punch/die in place of the index sensor and an indexing plate in place of
the rotor on the end of the spindle. It should then be quite easy to
punch the extra holes.
Making the new parts is not a major problem (I have a lathe with milling
facilities and a dividing head...)
-tony