Most were copyright infringement oriented .
Most 's function was only tape duplication , but when Sinclair Research launched the ZX Microdrive , copiers were developed to copy programs from audio tape to microdrive tapes , and later on diskettes .
Most were copyright infringement oriented , and their function was only tape duplication , but when Sinclair Research launched the ZX Microdrive , copiers were developed to copy programs from audio tape to microdrive tapes , and later on diskettes .