[net.micro] CD-ROMS -- access times

munck@MITRE-BEDFORD.ARPA (07/21/85)

  I don't understand exactly what the problem is; maybe a bad choice
of technology?  I saw a demonstration in 1976 of a great graphics display
built by Charles Lang at Cambridge U.  It used voice-coils and mirrors to
point a laser with tremendous accuracy and speed at a 5 cm square target,
writing with a resolution of 4000 line pairs. It was aimed by splitting
off a bit of the laser beam and counting interference fringes, giving 
essentially digital aiming with (I think) 24 bits of resolution.  I saw it
draw a street map of London in about 30 seconds, and then redraw it with no
visible thickening of the lines.  (The little square was being projected
on a 1m square screen.)

  So why not build a CD-ROM player that works that way?  Assuming that 
it's also capable of audio, you could use the high-res D-A converters
to drive the voice coils. (Or single voice coil, assuming a spinning
disk.)  Sounds pretty cheap to build, and more than fast enough.
            -- Bob Munck, MITRE Corp.
               (..linus!munck.UUCP)