ORIGINALLY PUBLISHED IN LIMA NEWSLETTER APRIL 1990 FIXING DISKS By: Andy Frueh, Lima UG We've all seen them. Those horrible little disk errors. For example, having 4394 free sectors on a SS/SD disk or when the computer refuses to find a file you just know is there somewhere. Some people throw these disks away saying they're useless. DON'T! Althogh these situations may look hopeless, a blown disk can be repaired. Blown or glitched disks come in three major categories. Physically altered, blown disk header, and blown file header(s). The first type is not repairable. Doing things such as cutting the disk or finding that a small child has fingered it (after eating chocolate chip cookies of course) effectively destroy both the contents of the disk and the actual media itself. Throw it away. Of course if the disk was in its envelope when not in use, it should be fairly safe. The seond type, blown disk headers, are slightly more complex. These usually have to do with the first sector or the directory map. You almost always need to use a special disk fixer program to set things straight. Although a skilled programmer may not need to use such a program, I feel it's a lot safer. The third type, blown file header(s) are very easy. Suppose you catalog a disk and it looks like this: FILEA FILEB FILET FILEC FILED Obviously, file FILET is out of order, which shouldn't happen. Let's also suppose that you can't manipulate FILED in any way (delete, copy, load, ect.). Using a cataloger, list all the files on the disk and place them in alphabetical order. Next, use a sector editor to inspect sectors 1-x. The value for x depends on the number of files. Keep looking until you have found each filename. As you spot the filename, put a small check by it as well as the sector number the name is found in. Next, edit sector 0001. Enter the hexadecimal mode. Every four characters equals one file header. Since your list is in alphabetical order, type each number of the sector header. For example if FILED has its header at sector 2, I would enter 0002 for the first four digits and so on. When you are done, write the sector and try cataloging and manipulating the files. The easiest way to do this is catalog then protect/unprotect all the files. If you can, you are in the clear. If not, more work will be required. Before you give up, try repeating this procedure, or find someone with lots of disk skill. .PL 1