Thread: Mini (3.5") CDs
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Dave Platt[_2_] Dave Platt[_2_] is offline
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Default Mini (3.5") CDs

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I have problems with a shrink wrapped unprinted pack of CDs. The drive read
and writes other CDs, includin an older pack of 3.5" I know I wrote to these
with an earlier (replaced) drive and I have problems with these CDs on
computers that are not mine. But since I have occasionally succeded, I ask if
it is something I did? Like writing speed?

Varying the burn speed may help... in some cases slower-is-better, in
a few cases faster-is better.

Some newer drives (e.g. combo DVD/CD) don't do as well with CD-R
burning as older drives... some new drives have an uncomfortably-high
_lower_ limit on burn speed (e.g. 4x or even 8x) and won't give a good
burn with some older media that requires a long burn exposure.

It's possible that the discs you've gotten are simply poor-quality or
defective, or have deteriorated in storage. If I recall correctly,
some of the CD-R dyes can deteriorate over a period of a few years and
won't burn well... especially if the CDs have been stored in poor
conditions (too much heat, direct sunlight exposure, etc.). And, some
off-label CD-R manufacturers make products that are best used as
Christmas-tree decorations.

Some CD-R software (e.g. cdrecord/wodim on Linux) can read the
blank-disc information that's encoded in the pre-groove wobble (the
"ATIP" data) and print out a description of what it finds... actual
manufacturer, recommended and acceptable burning speeds, and so forth.

A good drive will read the ATIP data, and then adjust its burning
parameters (laser exposure time, burning speed) to what it finds
there. A good drive will also do a real-time burning-power test
before it starts recording the real data, and optimize the "burn"

Also, check the center hub of the disc blanks to see if there's any
plastic "flashing" or burring around the hole. If the opening isn't
smooth, the debris can prevent the disc from sitting flat on the drive
spindle, and it will "wobble" as it spins. This will make it harder
for the laser focus electronics to keep the laser spot tightly focused
on the dye layer, and can increase the bit-error rate.