TDDCLN.THD --- Copyright 1987 by Phil Wheeler An original compilation of Compuserve Model 100 Forum messages for use by Forum members only. With regard to disk drives: "To clean or not to clean, that is the question" (Chalk that up to Summer Silliness, folks!). In this set of messages, the question is asked, and some answers are offered. This "old" THD file has recently been autgmented by some new material. Well, it IS summer again! The new messages include interesting info on the mechanical relationsip of the heads and the media. Message range: 153507 to 153599 and 170053 to 170154 Dates: 7/28/87 to 7/29/87 and 6/15/88 to 6/16/88 1987 Messages ------------- Sb: #TDD Maint Fm: Jon Kaplan 73337,1414 To: Anyone I need some advice on Disk Drive maintenance: i.e. should I be doing any? Like should I clean this thing or the heads or anything? I've been using the hell out of it, and it seems just fine, but it occasionally makes a high pitched whistling noise. Is that normal, or should I take it in for a check up? Fm: Tony Anderson 76703,4062 To: Jon Kaplan 73337,1414 You didn't specify which disk drive. However, there are fanatics on both sides of the question... whether to regularly clean and "maintain" a disk drive, or whether to totally ignore it unless it stops doing what it's supposed to do. Radio Shack (and of course others) has a disk drive head cleaner, in the form of a disk that you simply insert, and access the drive, which causes the head to be cleaned. I have one, and have never used it. High pitched whistling noise may just be vibration, or cheap disks. Don't worry about it unless it causes a disk to become unreadable. It may be that the particular brand of disks you buy don't have enough lubricant built into the magnetic coating. Fm: GARY DAVIS 72256,2551 To: Jon Kaplan 73337,1414 Personal opinion: The noise is normal; I use the Tandy Disk Drive Head Cleaning Kit (26-419). Have had NO problems, but of course that doesn't mean it's because of the cleaning! Maybe would have had no problem WITHOUT the cleaning! Confused? Me too! Fm: Al Pound 75715,1077 To: Jon Kaplan 73337,1414 I clean mine about once a month. Ocassionally, I get whines which sometimes go away by themselves and sometimes are fixed by the cleaning. Fm: Jon Kaplan 73337,1414 To: Tony Anderson 76703,4062 Thanks for the disk info. That pretty well jives with what others I've heard say, i.e. if it ain't busted, don't fix it. It does run contrary to everything I know about audio & video, but I think I'll follow it anyway. (Path of least resistance.) Fm: Tony Anderson 76703,4062 To: Jon Kaplan 73337,1414 Jon, I understand exactly where you're coming from on the head cleaning issue, having developed the technique of frequent cleaning of audio heads myself. But with the disk drive, the disk revolving at 300 RPM, and with a a nominal track diameter of 2.5 inches, a circumfrence of almost 8 inches, you have an effective head-to-media speed of 40 ips. Fast enough, I think, to "knock off" all dust or oxide particles that might accumulate. ... Haven't you ever noticed tape machines operating at 15 ips don't have to be cleaned as often as those operating at slower speeds? Plus that, the disk media is probably a better bonded oxide, and is not as prone to shedding as audio or video tapes, which is really what you're basing your experience on. Dust on the disk surface is unlikely, since the trap door closes upon removal. 1988 Messages ------------- Sb: #TDD cleaning Fm: RANDY HESS 73267,552 To: Tony Anderson Tony, I just purchased a cleaning kit for my TDD and the instructions require the user to "activate the drive for 20-30 seconds but don't suggest how. Since I am certainly not the first user to clean the TDD, I can't help but feel that there's a routine lurking in one of the DL's that will keep the head in contact with the cleaning disk for the right time but have been un successful in finding it. What are your suggestions? Thanks, Randy Fm: Phil Wheeler 71266,125 To: RANDY HESS 73267,552 Actually, Randy, you may be the first. The only two disk drives I've ever had problems with were the two in my old Kaypro -- which I had cleaned ocassionally. I now leave them alone, and they work fine -- and that includes three TDD's. Of course, if your TDD is acting up..... Fm: RANDY HESS 73267,552 To: Phil Wheeler 71266,125 Well, you see, um, Radio Shack is having a big "Tent Sale" and all the M100 stuff is going for .10 on the dollar, and, well, there was this 3 1/2" cleaning kit on sale for half price and,d well, I mean, who could resist ( and besides, the salesman did say he had been waiting for me.) Isn't a pound of prevention worth an ounce of cure (something like that)? Hey, all I'm askin for is a measly 20-30 seconds: my ERRORS usually last longer than THAT! Regards, Randy Fm: Phil Wheeler 71266,125 To: RANDY HESS 73267,552 Hmmm.... Thinking about your question. You could try formatting the cleaning disk, WITHOUT verification if that is an option. Or try reading a file (maybe about 20 files!) from the cleaning disk. Fm: Tony Anderson 76703,4062 To: RANDY HESS 73267,552 You can "activate the drive" by using any normal disk access command, such as reading the directory, or loading a non-existant file. This causes the disk to spin and the head to look for the directory; cleaning the head in the process. There isn't really a "right amount of time" to clean the head; no more than there is a "right amount of wipes with a Q-tip" to clean an audio head. While Denny and I both have a 3.5 inch cleaning disk, purchased on sale at Radio Shack at one of the LA Group meetings, I've never usedmine, and last I heard, Denny hadn't either. It's really a case of emergency preparedness... In case we ever need it; but normally you never do. Excessive or unnecessary cleaning can cause more problems than it solves. Suggest you use sparingly, and only if necessary -- if the drive is not reading data reliably from known good disks. Fm: RANDY HESS 73267,552 To: Tony Anderson 76703,4062 Tony, Thanks for your and Phil's excellent advice. I'll keep it in a drawer 'til I need it. BTW do most disk write programs "checksum" the write by seeing that what was stored was what was sent? Also, does the write head always float a few molecules of air off the disk or actually contact the disk. Is a disk "crash" actually the physical contact of the head with the disk or an electronic/byte phenomenon? Regards, Randy Fm: Paul Globman 72227,1661 To: RANDY HESS 73267,552 The head "float" is strictly for hard drives whose surface would become 'scored' if a fixed object make contact with it's spinning surface. The floppies work like magnetic tape and the read/write head makes direct contact. The floppy surface is quite flexible and makes contact with the polished and properly curved tape head with no damage to the floppy surface. There would be a small cotton pad against the unused surface holding the floppy surface against the read head with a gentle pressure. Fm: RANDY HESS 73267,552 To: Paul Globman 72227,1661 THANKS PAUL! It would seem that, unless the magnetic coating were to rub off the disk, the lubricants in the oxide formula would tend to clean/polish the head as it was used; the only pollutants then would normally be airborne or foreign to the disk itself which eventually collect on the head, resulting in poor read/write operation. With the self-checking disk operation you describe you could see trouble developing rather than all at once. Good Info! Regards, Randy Fm: Tony Anderson 76703,4062 To: RANDY HESS 73267,552 Most disk-oriented data that I've seen has always indicated the head "floats" above the media by a micron or two, and that the "classic" disk crash was a situation where a head had actually gouged out the recording surface of the disk, destroying data in the process. But since "crash" has developed into a sort-of generic term, it's applied to almost any type of system failure. I'd suspect it's more frequently used in the description of disk crashes, though. Fm: Don Zeikel 75775,1430 To: RANDY HESS 73267,552 I have used formatting without verification in the past (as in Phil's answer). Now that Powr-Dos is available here, you can get that option with the FORMAT utility.