Magneto-optical driveThe magneto-optical drive was a brief attempt to sell people on the idea of re-writable cd-roms before such technology was practical or available. Sealed in a dust-proof plastic case, the "cd" was actually an odd mix of magnetic material sealed beneath a plastic coating. Each write-cycle required both a pass for the laser to heat the surface, and another pass for the magnet to write the information. Suffice it to say it took twice as long to save any data vs the retrieval time. The NeXT computer was the first to offer this technology, but Canon evenually provided it to other customers. Aside from being slow, the technology also sufferred from the same price problems that plaugued other removable technologies at the time like Syquest et-al.