CD ROM Update for Archiving Flow Data

J. Paul Robinson (paul)
Thu, 21 Jul 94 12:20:24 EST

Several months ago I mentioned that we were going to start
using CD ROMS to archive both confocal and flow cytometry
data. Several people requested follow-up. For those
interested, here is a progress report.

CD writer: Philips 521 Cost US$+/-5,800 incl. software
($4,500-$5,000 without software)
Disks: 74 minute (650 meg) writeable CDs $17 ea
Operating systems: CDs can be read on all systems ie. PCs,
MACs, or SG systems

The Philips CD writer was bundled with recording software.
The software is the most critical component of the system.
We have had many problems with a program call CD Producer
which was bundled with the system. At this stage I cannot
recommend this package at all. We paid $1000 for this and it
is currently banished to the unusable software shelf. Bad
mistake to make! We suggest using Corel SCSI version 2 a
$100 package that is great value. I won't discuss CD
Producer software unless someone particularly wants the
details.

ADVANTAGES:
1. The main advantage is 600+ megs of images can be put onto
a disk that is relatively protected and can be read on any
computer with a $200- 300 CD rom reader
2. You can put multiple sessions onto the disk, so you don't
have to fill it up in one go (you do need multisession
capability CD RPM extensions for this)
3. The cost is low, not as low as tapes, but much more
convenient
4. It is really convenient to provide the many users of our
facility their data on a CD rather than them deal with
archival problems

DISADVANTAGES:
1. The cost of the writer is high, but will no doubt come
down significantly in future
2. It takes about 35 minutes to burn a 74 minute disk
(double speed writer)
3. We still make 2 copies of every CD (just being cautious)
4. There are many issues of drivers, setup etc that is not
as easy as one might hope
5. Speed of reading is not nearly as fast as opticals, but
you don't need a special reader to read them
5. We put a 1750 meg drive on the computer to handle a full
CD, plus a mirror image, but using Corel SCSI this is not
necessary. It is important, however, to have a fairly large
amount of disk space available. The best possible situation
is to burn a full 650 megs in one go. We will close off a CD
upwards of 400 megs just for convenience.

CONCLUSIONS:
We have used the system for 6 months now and have made all
(hopefully) of the possible mistakes. We have now a simple
system for making the CDs and feel comfortable with using
them on a routine basis. It is hard to compare with
rewritable opticals which are fast and readily available.
Clearly the issue is universal compatibility, stability (how
long does a CD last - several years at least), and long term
(at least 10-15 years) availability of CD technology.

Paul Robinson
Purdue University Cytometry Labs


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CD ROM Vol 2 was produced by staff at the Purdue University Cytometry Laboratories and distributed free of charge as an educational service to the cytometry community. If you have any comments please direct them to Dr. J. Paul Robinson, Professor & Director, PUCL, Purdue University, West Lafayette, IN 47907. Phone:(317) 494-0757; FAX (317) 494-0517; Web http://www.cyto.purdue.edu EMAIL robinson@flowcyt.cyto.purdue.edu