dennisg@fritz.UUCP (02/25/87)
Well, it finally happened. I've got a dead disk. Here's what I tried to recover it. Perhaps you can offer some suggestions? The corpse is a 400K (single-sided) MFS. It contains mostly MacWrite documents, with a few MacPaint documents thrown in for good measure. Inserting the disk while in the Finder yields a dialog box that says "This disk is damaged", and offers EJECT and INITIALIZE. No offer is made to repair the disk. I'm using Finder 5.3, 1986 System 3.2, 2-Jun-86. Then I tried to make a sector copy using Copy II Mac (4.2, 1984-85). This produced messages that blocks 3, 8, and 18 had errors. I invoked the bit-copy on tracks 0 and 1. This should result in an identical copy of the gronked disk. Actually, I made a couple bit-copies of the bad disk. In the subsequent steps, a copy was used. The original bad disk is safely locked away. I tried the built-in scavenger by booting the Mac with the bad disk while holding down "option"/"clover". The system has Original skinny-mac ROMs. Mac churns briefly and spits out the disk. I expected that, it has no system folder. After rebooting with a good disk, the damaged one is still bad. So I got out Mac Repair 1.0, 1984. This one made some promises, in exchange for a Shareware fee of 10 Francs the first time it saved a disk for me. At least, that's what I think it said, as all of the messages were in French. This tool works by moving salvaged data to a virgin disk. It churned for awhile, then asked me to hit the mouse. Then it rebooted the machine. The result of this operation was another bad disk. Inserting the disk while in the Finder yields a dialog box that says "This disk is damaged", and offers EJECT and INITIALIZE. So I pulled out MacTools 4.0, 1984-85. When I fed the disk in, I got a dialog box that said that the disk was bad and offered REPAIR, EJECT, MOUNT, INIT, (something else). I picked REPAIR. Things cranked for awhile, and I got a dialog proclaiming that the repair failed. The copy of the bad disk was left malformed. It had only one file, 0K long, but it was recognized as a valid disk by the Macintosh (with a new name like "RepairedDisk"). I tried MacTools again. This time hitting MOUNT. The first screen of boot block info came up. I clicked on the arrows, reading a block at a time. When it hit the first bad block, I got a dialog that called the disk bad. It suggested that I try another one. Thanks fellas. My last try involved Patch Disk 1.0, Mar 18 84. This one turned out to be a generic sector editor. I used Copy II Mac to sector-copy all of the good sectors to a virgin disk. Then I used Patch Disk to read the bad sectors, one at a time, and write them on the destination disk. This should turn sectors with bad CRC into good sectors on the copy. If a couple of bits of data were corrupted, instead of the checksum itself, at least some of the files should be retreivable. The result was the same as Mac Repair, causing me to speculate that all that tool did was format a target, and copy from source to destination ignoring read errors. Any ideas, gang? Responses to me, please. I will digest for the net.
dilvish@dartvax.UUCP (03/05/87)
If people would like, I could post my mac disk recovery manual. It's fairly up to date, as I wrote it this Fall while consulting here at Dartmouth. And believe me, I fixed a lot of disks. Unfortunately, I have no info on double-sided disks -- none of the tools I used would let me fix them. But what I have is fairly useful in most cases. Anyway, if you're interested, send me mail, and I'll decide whether to post or what. Oh, yeah. I didn't write the whole thing. Dave Green, the previous consultant, began writing it. I just finished it off. So credit where credit is due.
keeshu@nikhefk.UUCP (Kees Huyser) (03/06/87)
In article <5777@dartvax.UUCP> dilvish@dartvax.UUCP (Jim Van Verth) writes: If people would like, I could post my mac disk recovery manual. Please do! -- Kees | UUCP : keeshu@nikhefk.uucp or : {[wherever]!seismo}!mcvax!nikhefk!keeshu | FIDO : kees huyser at 28/9 or 500/11 | BITNET : u00212@hasara5.bitnet | SNAIL : kees huyser, NIKHEF-K, PO Box 4395, 1009 AJ Amsterdam, Netherlands