Chris M wrote: Just curious how, or even if, old design drawings and such were preserved in the old days. I could barely venture a guess as to when the first optical recording drives became "useful", all I remember is a friend obtaining one of the first (locally) cd players for his auto in ~the summer of '87. I was in contact with a few of the people who were involved w/the Mindset computer, and had hoped I would obtain info on the custom vlsi chips it used, in any form of course. This just lead me to ponder when this stuff started *appearing* on cd's and such. Can anyone name the different optical CD formats that modern readers can't work with? I know there must be a few... ------------- Billy answers: There are two parts to your question. The first is how old design drawings were preserved. In all the companies I have worked for in the last 45 years, the drawings were destroyed. Some individual copies survived. And patent applications remain. But all design drawings were destroyed as a matter of policy. That way there was no way support obligation coming up long after it was cost effective. And it makes patent challenges difficult, especially prior art arguments. Even today, most of the design archives where I work have a very limited life time. The second question is a little more logical. Early on, CDs were not well accepted. One reason was that they were rigidly defined by a document called the "Red Book" which precisely described the format, the media, the recording method and so on. To get access to the Red Book, you have to sign a conformity and privacy agreement. The technology is much more complex than that used on magnetic recording. The huge base of vendors building according to the spec has very much limited the variation of formats. And this rigidity has been kept up on the DVDs. I have seen modern readers demostrate this compatibility by modern devices reading some of the very first CDs made in the labs at Philips. While there may be some odd formats, I'm not familiar with any of them. The start up costs to create the media and OPUs prevent any but the most brave of souls Whereas a unique floppy or hard drive format was easy to do. Any engineer with a "better idea" could throw together a circuit and be shipping in a few months. His costs often were only one small media formatter. You can see this effect if you try to list all the different floppy formats for 8" and 5.25". There were dozens of different formats. At MPI, I remember a wall chart showing the relationship of more than 50 formats that we were shipping. Things settled down a little with the 3.5" floppies, but there were still variations floating around. And a few odd ball experiments like the 3 inch drive. MPI had a 1.6" floppy in the lab, but fortunately it died. IOmega continued to play with floppy media for years. A wonderful example is their Cricket drive - every PC collection should have one. An optimist would say the CD people learned from the floppy fiasco. A cynic would say nobody could afford to be an indiviualist. Billy