Path: utzoo!attcan!uunet!know!news.cs.indiana.edu!ariel.unm.edu!wayback.unm.edu!honeywel From: honeywel@wayback.unm.edu (Honeywell Field Service) Newsgroups: comp.sys.apollo Subject: Re: How to park a disc for shipment. Message-ID: <1990Dec10.170633.4656@ariel.unm.edu> Date: 10 Dec 90 17:06:33 GMT References: <9011302223.AA26346@richter.mit.edu> Sender: news@ariel.unm.edu (USENET News System) Organization: University of New Mexico, Albuquerque Lines: 45 Regarding parking disk drives: The newer technology drives park their heads on power down. Many models also include a solenoid to lock the carriage in place after power down--this solenoid is the clicking you hear when first applying power. Some of the older DN300's did have a manual carriage lock. The way to check is to gently turn the drive on its side (after powering it down!) and look for a hole in the bottom of frame towards the front. If the cutout is present, just look for a slot type screw just inside. If the slot type screw is present, you are the lucky owner of a drive with a manual carriage lock. There were two different models of drives in the 4xx 6xx product lines. If you have a Priam disk, there is a spindle lock (just to keep the platter from rotating during shipment) present which clamps the cooling vanes in the spindle assembly. If you forget to unlock this, the extremely loud sound as the spindle vanes rip the plastic clamp to shreds will jar your memory. I don't remember whether the other model drive was an NEC or Fujitsu, but in any event there was a carriage lock on the drive towards the very front of the unit. It is difficult to get to or even see, but with a flashlight you should be able to spot a lever with red plastic handle. If you forget to unlock this drive after shipment, it won't alert you by any loud noises, but will eventually blow the driver transistors. On another subject, if you lose the badspot list off the media you have a potential serious problem. FBS (Find Bad Spots) will never locate all of the spots that the manufacturer has identified as bad. The manufacturer margins the read write levels to locate badspots, this is option not available to FBS. There are a few customers who have had success using FBS to replace a lost flaw map, but I can guarantee that these are in a minority. If you have destroyed your flaw map inadvertently, check the drive itself for a written record usually attached to the top of the unit. The old CDC 500MB drive usually had one taped to the top and a second was hidden in the HDA next to the motor. The manufacturers used to maintain a file copy of the flaw map which they would send to you for a small fee (CDC used to charge $50). If you can't find a copy of the flaw map, then you could try running FBS over a weekend and pray that it will find enough badspots. What happens is that FBS finds the obvious flaws and then you load all your data on the disk. Everything works fine for 3 to 6 months and then you find one of the other flaws the hard way. OK so you map the new badspot out and you're fine again, until in another 3 to 6 months you find another. If this scenario occurs, its time to ship the disk to the manufacturer or a repair depot for media analysis. Mike Thomas, Honeywell Third Party Services.