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-
- BD BAD DISK PROGRAM
- ===================
- 11 May 1987
-
- Irv Hoff
-
- NOTE: BD04 works with either CP/M v.2.2 or v3.0
-
- GENERAL:
- -------
- 'BD' stands for "bad disk". It reads the records on a disk (floppy or
- hard) and finds those that are unacceptable. It then makes a file named
- [LOCKED].OUT containing those records. This prevents them being used in
- any new files, thus allowing normal use of the disk. It also shows the
- names of any files that might be defective. It works with CP/M v2.2 or
- v3.0 (often called CP/M+). It is 5-1/2k in length.
-
- Small floppies usually have 1k blocks, larger floppies 2k blocks. Most
- hard disks use 4k blocks although a few have 8k blocks. 'BD' counts the
- blocks in increments of 5. A disk with 360k would thus show 180 blocks.
- A hard disk partitioned for 8 Mb per drive and using 4k blocks will show
- 2048 blocks (etc.)
-
- If a block has one or more bad records, this informaion overwrites the
- progress report. It then resumes the progress report on the following
- line.
-
- This gives an attractive display.
-
-
- TO USE:
- ------
- Any of the following three will work. The first permits removing the
- disk from the current drive and replacing with the disk to be checked.
- Useful for only one drive or if you want to check a disk in any drive.
- (For floppies, it is often beneficial to check the same disk in every
- drive you have, they occasionally act differently in different drives.)
-
- A>BD activates pgm, will ask what drive
- A>BD B activates pgm, checks drive B:
- A>BD B: activates pgm, checks drive B:
-
- NOTE: The program can be aborted at any time, but
- but in a somewhat unusual manner. Just type
- type CTL-S to stop the display and then CTL-C.
-
-
- EXAMPLE 1:
- ---------
- If the disk already has a [LOCKED].OUT file from a previous check, the
- results might look like this:
-
-
- BD v04 - bad disk blocks/files
-
- check drive: A (automatically logs in that drive)
- checking....
-
- prior check: 127
- prior check: 148
- prior check: 149
- prior check: 160
- this check: 162
- prior check: 204
- this check: 225
-
- 494 (total data blocks checked)
-
- bad blocks: 7
-
- bad files:
-
- A:CRT ASM
- A:LIST DOC
-
- A>
-
-
- As it checks the file, if the current block has previously been reported
- as bad, that is shown as "prior check", and if not previously reported,
- it shows as "this check". Thus you can see if the disk has new problems
- since the prior check. You can manually erase the [LOCKED].OUT file if
- you wish and rerun the program to see what it will report "this time".
- (If results vary more than slightly, you may have a bum drive that is
- giving erratic results, or that initially did a poor job formatting the
- disk.)
-
- When showing 'bad files' it may show the same file name more than one
- time, indicating that particular file has multiple bad areas and will be
- difficult to rebuild into a normal file.
-
- NOTE: 2k blocks have 16 records. Thus a bad
- block could have from 1-16 bad records.
- 4k blocks have 32 records. Thus a bad
- block could have from 1-32 bad records.
-
- EXAMPLE 2:
- ---------
-
- This is what you are hoping to see, for a normal disk:
-
-
- BD v04 - bad disk block/files
-
- check drive: B
- checking....
-
- 494
-
- bad blocks: 0
- bad files : 0
-
- B>
-
- OPTIONS:
- -------
-
- 1) 0103h sets the user area for [LOCKED].OUT file.
-
- 00 = user area zero
- 0F = user area 15
-
-
- 2) 0105h turns progress reports on/off. You may want a
- version with them turned off, so you can use the
- printer to display the results.
-
- 00 = no progress reports
- FF = progress reports shown (anything but 00)
-
- (then save 22 pages if using DDT or SID, etc.)
-
- - Irv Hoff W6FFC
-
-