At 05:57 PM 11/17/2014, Don Hills wrote: So far, no luck on that front. I think it would require a tweak in firmware. At 06:07 PM 11/17/2014, drlegendre . wrote: Adding a reflective layer to the back was a first and obvious idea, but upon deeper reflection I don't think it's the right answer. The pits receive the sputtered aluminum. If adding a backing layer was the answer, you'd think CD-ROMs would've been made that way in the first place, as it's easier. It's not a matter of boosting reflectivity in general, it's about accentuating the difference between pits and lands. (I tried Krylon "Looking Glass" spray paint on a couple test discs. Although this paint does a wonderful job of mirror-izing glass, it turns out more gray on plastic.) If the anecdote about early CD drives being able to read non-aluminized discs is true (and I believe the stories) then it would seem the answer would be to find a drive that used the old Phillips read heads and somehow ask it to dump a raw image of the bits it finds, in order to allow another system to interpret the image. High Sierra wasn't adopted until late 1986, and ISO-9660 after that. The CM100 apparently only works on PC and XT era hardware. I saw mentions on the web that even a 25 Mhz PC is incompatible. At 02:51 PM 11/17/2014, Mouse wrote: I'm not quite sure what you mean here. Wikipedia has an explanation of the process: http://en.wikipedia.org/wiki/Compact_Disc_manufacturing The pits surface is normally aluminized and then covered with some sort of acrylic or lacquer. I too wondered if there's not some optical characteristic of that boundary that could work like aluminum. But as you mentioned, detection normally uses the phase shift, and that's dependent on the frequency of the light. You'd need to develop an entirely different optical path. - John