Hi, On Tue, 24 Jul 2001 Jerome Fine wrote: If you get a chance, check out a later-generation MO drive. Seek times and transfer rates are much quicker. I assume a similar accelerated-aging regime to testing CD-R discs would work; high temperature and humidity. What you can do (and this applies to CD-R discs as well) is check the block/bit error rate. After writing to a new disk, use the SCSI READ LONG command to read the raw data from each sector (this consists of the sector data and error correction info). For each sector, see whether there is a correctable error. End up with a figure for the percentage of sectors with correctable errors. Do the same thing in a few years time, and see whether there is any difference. A more accurate variation would be to record how many "bad" bits are in each correctable sector. Depending on the drive, you may be able to get it to automatically log the number of times it has to use error correction. You could establish a proportion of the maximum possible correctable bit errors, and reject a disk if its maximum goes over that. (E.g., if up to 80 bit errors in a sector are correctable, you might reject a disk which has a maximum of 50.) Before evaluating error rates, make sure the disk's surface is clean; if you have been using a particular disk heavily for years in a polluted/dusty environment, dirt on its surface will probably affect the error rate. You're interested in the "real" error rate, not errors which go away after cleaning. Also make sure your drive's lens is clean. You can probably leave data alone for much longer than 5 years. Various MO media manufacturers quote media lifetimes of 30, 50 or 100 years. Of course they probably all use different criteria to come up with a lifetime figure... Pretty much any ISO standard 5.25" MO drive will work with the 600/650MB disks that the SMO-S501 uses; you are not restricted to that particular drive. -- Mark