CFOG's PIP, May 1986, Volume 4 No. 7, Whole No. 43, page 6

BDOS Error on B:

by Hanns Trostli

Believe me, I have had my share of the dreaded BDOS Errors. One of my disk drives behaved erratically and suddenly the disk and especially the directory had bugs in them. I tried many ways to overcome that trouble. Maybe my experience will be helpful to similarly worried Osborners.

First: save your files frequently. Using Smartkey II, I have programmed my <.s> or SuperShift s key to ^K^S^Q^P^M -- WordStar for save and resume editing, return to the cursor's last prior position, enter a <cr> to go to the next line. You can also program a special function key to do that. In the case of a small file, say 3 pages, it takes about 20 seconds.

Second: do make backups, always. This is like taking out insurance -- it costs some but it is invaluable in case of a loss.

Well, all this is old stuff to most readers. But what to do in case of real trouble? I have been using DU and DDT to salvage the undamaged files. This takes quite some time. One can also reconstruct many damaged files this way. Having spent many hours doing that I found two ways that help, at least partly.

If BDOS Error happens suddenly while you are working, try taking your disks out, put a disk containing Findbad.com in one of your drives (I have it on my WordStar disk) and the probably damaged disk in the other drive. Run Findbad and note the bad sector number. Then run Dirmap, using your printer. You will then find which file has the offending sector and if you are lucky you will be able to repair it. If it is a "COM" file, which you can't read, and which is probably quite okay on your backup disk, delete it and copy it again to your bad disk from the backup disk. Run Dirmap again and you will see that the location of the file has been changed, avoiding the now isolated [USED].BAD sector.

The other solution I have found uses a program called Fusa.com, which I have submitted for the CFOG library. [It's on -CFOGUTL.017 - bhc] Fusa is a program by my friend Peter Chirivas, based on Wash.com and works exactly like Nswp. But version 2.07 takes up 12k bytes and Fusa is only 8k bytes. The Fusa setup is much more practical than Nswp, because it shows the names of all the files on the disk at one time. Fusa doesn't do a CRC check when copying files to guarantee the accuracy of the copy, but I find this a minor disadvantage against the otherwise great advantages which you will note as you use it. I have Fusa on all my program disks.

The way I use Fusa for salvaging damaged disks is the following: I put Fusa in drive A: and a new formatted disk in drive B:. I enter Fusa B:<cr>. Fusa finds an empty disk and asks: Relog? Before you answer that question, take the disk out of drive A: and put the damaged disk in. Then type A. Now Fusa will try to log on to the A disk and won't succeed: you will see BDOS Error on A: on your screen. Don't despair.

Push the <cr> key 16 (yes, sixteen) times and then you will suddenly see the directory of disk A -- at least what there is still on it. Now tag all the files and then type M to mass copy to B:. Fusa will now transfer whatever possible to disk B:. Sometimes BDOS Error on B: will appear again while the files are being transferred. Push the <cr> until the transfer is completed. Take note of which files have been giving trouble. I have found this to be the most practical and rapid way to save most of my files spending only minutes instead of hours. If need be, I can still check into the damaged disk with DU.

[Pip.com can be used similarly. Put the bad disk in drive B:. Put a good disk with only Pip.com on it in Drive A:. If you have the revised version with [R]eset and [Q]uick repeat options, you can use any disk with Pip.com, change disks after Pip has been made active, and enter R<cr> to reset the disk. Enter Pip a:=b:*.* [WVOR]<cr>. Keep on hitting the <cr> key until you get too tired to keep it up or you get the A> prompt back. In the meantime you may see BDOS Error on B: dozens of times -- just keep leaning on the <cr> key. The files from many a disk have been recovered by this technique by many CP/M 2.2 users -- sorry, users of CP/M 3.0, the CP/M 3.0 version of Pip.com it's so sophisticated it knows there's a bad sector and quits! -- bhc]

Of course, I use Fusa for many other things: copying files, having a quick look at them with the V command, the mass delete function Q is extremely quick and troublefree, as is the R(ename) function. I call it up from within WordStar whenever needed.