Subject: Re: Another request From: dempson@actrix.gen.nz (David Empson) Date: Tue, Jan 5, 1999 5Ç17 Message-id: <1dl6mz7.12q3ta11xcac6yN@dempson.actrix.gen.nz> Julian P Watson wrote: > I would appreciate some help. Recently, my 3.5" disk drive > (the one which came with my IIgs) died. I replaced it with a > UniDisk 3.5" drive. Since installing the latter, it seems to > want to run, the red light comes on as if it is looking for a > disk to run. This happens once a second. This does not happen > when I use ProTERM and/or AppleWorks 5.1,..only while the Finder > is on the desktop or any other GS/OS program is running. This is easy to explain. Finder regularly polls all removable devices to see whether the disk has been changed. An exception is the 5.25" drive, which has no reasonably quick and quiet method of detecting this. The same applies to the Standard File selection dialog boxes ("Open..." and "Save As..." commands). 8-bit software doesn't usually care whether a disk has been changed until you actually go to use it. An exception would be Apple II Desktop, since it has a Finder-like display that needs to be updated immediately if a disk is removed. For an Apple 3.5 Drive, you can hardly even notice this polling, as the drive select light goes on for something like 50 milliseconds (one twentieth of a second), but you can see it if you look very carefully. The method used to poll a UniDisk 3.5 is somewhat slower, due to the way the drive operates. This means that you get a very noticeable pulse on the drive select LED every time the drive is polled. Don't worry about it. There isn't anything you can do about it, other than replacing the drive with an Apple 3.5 Drive (which is a good idea, if you can locate one - it is considerably faster than the UniDisk 3.5). -- David Empson dempson@actrix.gen.nz Snail mail: P.O. Box 27-103, Wellington, New Zealand