jhs@MITRE-BEDFORD.ARPA (04/27/87)
Ray Wong's problem with the erratic disk behavior *COULD* be due to a dirty magnetic pickup head. However, I would think this would show up as an inability to format diskettes properly before it would show up in READ errors. But, as I always say, "Only the Electrons Know for Sure". At least this is consistent with erratic behavior and normal operation on another disk drive. The division into "good" and "bad" classes of disks *COULD* be due to differences in magnetization levels of the different disks. To test this hypothesis, you should obtain a cleaning kit and clean the head. I believe there are cleaning diskettes that wipe off the head. I would probably prefer the tried and true method of isopropyl alcohol and Q-tips, but that may necessitate taking the case apart and you may prefer to avoid that. If it is a dirty head, you'll see a definite improvement right away, especially if you use the alcohol method. Also, if you use a cleaning diskette, I should think you would see a lot of rust-colored residue on it after cleaning. If you open the case and look at the head before cleaning it with alcohol, you will see the iron oxide all over the head (and everything else, probably). If this turns out to be your problem I suggest you change diskette brands, as you should not have that much junk on your head after only a few months. It's probably a good idea for *EVERYBODY* to clean their diskette drive heads once in awhile. The higher the density, the more critical it probably is. -John Sangster / jhs @ mitre-bedford.arpa