DiskOpti
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JOHNBEST NOTE
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A very under used utility, a floppy disk optimiser but it really makes
a difference - give it a try.  I always optimise a disk when I think Ive
finished adding files.

AUTHORS NOTES
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The purpose of this program is to copy an entire disk in a way which will
allow the files to be read faster by rearranging the data blocks. When the
system writes files on a disk, chances are the data blocks allocated for this
file won't be contiguous and be spread all over the disk. This is the reason
why we hear the disk drive's head go back and forth when the file is reread.
It then takes more time to read the file and adds wear and tear to the disk
drive mechanism. This program will copy all the files on a disk making sure
that the data blocks for each file are consecutive. Depending on the number
of directories and files on a disk, the process can take up to 6 minutes to
complete.

Usage of the program is straight forward, place the disk to be optimized in
one disk drive and a formatted disk in another drive, then select the
appropriate menu selection, for example df0: -> df1:, this means the source
disk is df0: and the destination disk is in df1:. Then  wait until the
process is complete.

In the Project menu you will find the List and the Save options;

List: Will make a list of all files, directories and headers of the source
      disk. No copying is done.
Save: Save the list either on the prt: device or on a file.

You can also do a save after the disk as been optimized.

The list is divided in 8 columns:

  1- Header block number of the file or directory.
  2- Root block number.
  3- Block number of a file with the same hash code of the current file.
  4- If the file has more than one header block (uses more than 72 blocks),
     block number where the block list continues.
  5- File or directory header block position in the parent directory
     (between 24 and 308).
  6- Total number of blocks used for this file, including the header block.
     This number is always 1 for a directory.
  7- 0: if its a directory or 1: for a file.
  8- Name.

All this information can be useful for those of you who like to take a look
at the data directly on the disk's blocks.

Try this test to check the improvement of an optimized disk.
  1- Select a disk that has a number of drawers with icons.
  2- Open all the drawers after you make sure the write protect tab of the
     disk is off (very important).
  3- Do the same with the optimized copy of the disk.
  4- Now measure the time it takes for the icons to appear when you open the
     disk icon of the original disk.
  5- Do the same for the optimized disk.
  6- Compare both timings. The more icons are on a disk, the more the gain.
     Some times as much as 100%.

This program works either from the Workbench or the CLI. It is entirely
written in assembler for faster operation and smaller size. You can also use
the included DiskView program to look at the position of the file and
directory blocks on the disk.

Conclusion:
I still have to work on the program to make the Dir command faster while
keeping the other timings the same. For the rest I will let you make your own
conclusions.

All comments, questions and suggestions are welcome.


                           Claude Abraham
                           1999 Place Jules Léger
                           St-Bruno, QC, Canada
                           J3V 5M6