CompuServe Messages

This is a GREAT queation!! The total life of a CD-ROM is dependant on the reflectivity of a laser from the pit level to a photo sensor. An early test of the robustness of the CD was demonstrated at a press announcement by SONY at the 1980 Audio Engineering Society annual meeting at the Los Angeles Hilton. As the story goes: Sony was going to make an announcement that would revolutionize the audio industry. The announcer was Toshi Doi, the father of digital audio. The announcement was to be given after a formal sit-down dinner. Doi entered the room, sat down at the table, and started on the salad. He poured three different dressings on the salad in a theatrical style. Then, with a gradiose move, proceeded to cut his lettuce voraciously both vertically and horizontally. By now, everyone was watching and waiting for that which was to follow. Doi reached down into the salad bowl and retrieved a dripping compact disc(with knife marks across the read side.) He wiped it off on his coat, put it in the CD reader, and the press was treated to their first playback of the CD. The read side of the disc is almost one disc thickness from the pit plane. The painted side is only 30 microns from the aluminium reflective coating. If Doi had cut the disc on the painted side he would have pulled up the thin Aluminium coating over the pits and caused a reflection failure. If you see someone cutting the read side of a disc to proove its robustness, ask them to turn it over and cut the label side. It won't play if you do this. Cheers, John L. Sands