💾 Archived View for mirrors.apple2.org.za › archive › apple.cabi.net › FAQs.and.INFO › DiskDrives › … captured on 2023-01-29 at 07:48:02.
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Newsgroups: comp.sys.apple2 Path: news.uiowa.edu!chi-news.cic.net!newsfeed.internetmci.com!news.sprintlink.net!news.uoregon.edu!waikato!comp.vuw.ac.nz!actrix.gen.nz!dempson From: dempson@atlantis.actrix.gen.nz (David Empson) Subject: Re: SuperDrive HD-notch detection Message-ID: <DGs9pC.823@actrix.gen.nz> Sender: news@actrix.gen.nz (News Administrator) Organization: Actrix - Internet Services Date: Sat, 21 Oct 1995 05:24:47 GMT References: <20OCT199520034610@vax2.concordia.ca> X-Nntp-Posting-Host: atlantis.actrix.gen.nz Lines: 47 In article <20OCT199520034610@vax2.concordia.ca>, Mitchell Spector <spector@vax2.concordia.ca> wrote: > > Quite a few of my Double-Density disks were unreadable by the > SuperDrive, both a mix of ProDOS 800K and MS-DOS 720K. [snip] > Later I noticed all these disks had something in common -- a square > imprint on both sides where the High-Density detection hole is normally > cut in the plastic. There is _not_ a hole here, just a small imprint in > the plastic. I took a piece of masking tape and covered the imprint, then > all those disks read fine! So it would seem the SuperDrive is being super > sensitive about the detection hole, when in fact there is _none_! Is this > at all normal? No. Mine works fine with DD disks that have an indentation in the top and bottom of the disk where a hole would be for a HD disk. The SuperDrive uses a small vertical microswitch (black base and white post) to detect the presence of a disk, write protect slider and disk size hole. It sounds like the disk size switch is being overly sensitive. (Earlier Apple 3.5 Drives use a standard microswitch with a metal arm to detect the disk presence and write protect switch.) If I look into the front right side of the disk slot in the drive, I can see two of these switches on the right side. One is visible just under the edge of the disk guide bracket (when the disk is in the drive, this bracket moves down, closing the microswitch). The second one is about seven millimetres to the right, in line with a hole in the disk guide bracket. This is the switch that detects the disk size. It is noticeably taller than the disk detection microswitch. This switch may have been worn down, or may not be extending to its full height. You may be able to identify this by pressing down on the switch with a small screwdriver, and see if it easily returns to its full height, or if its progress seems to be impeded. The switch base may have some dust or other gunge in it. One possibility would be to replace the microswitch, but it may be difficult to get access to the circuit board, and to find a replacement. A better solution might be to use a touch of glue to extend the height of the pin (make sure it is dry before putting a disk in!) -- David Empson dempson@actrix.gen.nz Snail mail: P.O. Box 27-103, Wellington, New Zealand