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1979-12-31
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****************************************
* DATA DIET DEMO *
* Program by Keith Gerdes *
* *
* Copyright 1991 Double Click Software *
* *
* You may order Data Diet now for only *
* $59.95 *
* (Introductory offer expires 12/1/91) *
* *
* Call us at (713)977-6520 to order. *
* Or send: *
* $62.95 (in US) *
* $64.95 (outside US no personal cks) *
* (includes shipping and handling) *
* *
* Double Click Software *
* PO BOX 741206 *
* Houston, Texas 77274-1206 *
****************************************
=================================================================
The following is a brief excerpt from our DATA DIET manual. This
will give you an idea on how to use the complete package.
Data Diet Demo is configured to use drive C only. If you are
using a floppy based system, you will need to setup a RAMdisk as
drive C.
=================================================================
Welcome to Data Diet
DC Data Diet is a unique product for the family of Atari TOS-
based computers that will save you megabytes of disk space
efficiently and silently using a seamless and transparent
integration into GEMDOS.
We have designed Data Diet to be as fast as possible, using a
proprietary compression method which provides excellent
compression at an astounding speed. In fact, speed was one of
the most important factors behind Data Diet's design. Compared
to similar programs on other platforms (Macintosh and IBM), Data
Diet blows them away hands down! We are certain you will be
equally thrilled by the substantial data storage savings.
Data Diet uses a unique method for solving the question: How do
you perform realtime data compression?
Basically, several different methods could be used to provide
realtime data compression:
1) Create a single file which acts like the disk drives. All
data is read from and written to this file, being compressed as
it goes into the file, decompressed as it comes out.
2) Make a single partition act like multiple disk drives,
basically use the entire partition as one huge file, similar to
#1.
3) Run through a "shell" program, decompressing any files you
wish to use before the shell runs the specified application,
recompressing the files after you have exited back to the shell.
4) Use the Data Diet method.
Numbers one and two above have severe restrictions, namely that
the file system must be completely rewritten to make the "file
disk drive" look like a real drive, and you must completely back
up your hard disk, repartition your hard disk, then restore all
the files back into the "file disk drive." Additionally, every
disk write requires compression, thereby really slowing your
system down.
Additionally, should the file become corrupted or attacked by a
virus, then all of your programs and data can be lost.
Number three is extremely limited in scope; you'd need to know
what files you will be using before you run the shell, and
launching a program from a shell can cause compatibility problems
with some software.
Briefly and without going into too much confusing detail, once
installed, DC Data Diet waits until a file operation is performed
before it goes to work. If the file is dietized, it is
decompressed and stored in a temporary working directory. When
the application accesses the file, it is actually accessing the
temporary file in the work directory. Using the decompressed
temporary file has the added benefit of allowing all disk
operations on that file to be full-speed. When the application
writes to the file, it again is writing to the temporary file,
not the original. Finally, when you exit the application, the
file is compressed and saved back to the original location.
Data Diet Method Best?
What advantages do you get using the Data Diet method over the
others? Several, in fact.
You don't have to treat your hard disk special in any way. To
install Data Diet you don't have to reformat, repartition or even
backup your hard disk (although you should always keep a backup
of your data).
You get a big difference in speed. First of all, Data Diet uses
a proprietary compression method which is lightning fast (we
guarantee it's the fastest on the Atari computers), secondly, the
data compression usually occurs when you run or exit a program.
Therefore data access while you are using your favorite program
is completely full-speed with absolutely no slowdown.
Data Diet will also compress files to a remote network drive (can
any other realtime programs do that?).
Additionally, Data Diet gives you a lot of flexibility. You can
exclude files, folders and drives you don't want compressed,
choose between two compression methods and specify the use of one
compression method for files over a given size
Data Diet Tools allows you to compress, decompress and get
statistics about a single file, groups of files, directories,
or your whole drive, using any file mask.
The All-Important Work Directory
Almost nothing is as important to Data Diet as the work
directory. The work directory is a temporary storage place for
your decompressed diet files.
When you open and use a dietized file, you are actually
manipulating a temporary file which is kept in the work
directory. The original file doesn't get touched until you
actually exit the current application (this may vary slightly
based upon your configuration and use).
** Data Diet Demo **
Data Diet Demo will create and use the work directory on drive C,
as the folder C:\DATADIET.WRK
The Data Diet Front End
The program/desk accessory DATADIET.APP/DATADIET.ACC is the
front-end to the actual Data Diet handler, which does all the
work. The Data Diet front-end is not required to be installed
unless you want to change the configuration of Data Diet or you
wish to 'keep tabs' on what Data Diet is currently doing.
From the Data Diet front-end you can get information about the
files currently accessed, change the current configuration or
call up Data Diet Tools to manipulate files.
The Data Diet Front-End Main Menu
The Data Diet front-end main menu is composed of several parts:
File information lists the files in use by the current
application. Information displayed in the main menu is the name
of the file and its current compression type. A crossed box
under the compression type of OFF, A, or B and RO (read only)
indicates the current setting.
Clicking on the filename in the main menu will display additional
information about the file.
You will see the complete path and filename for the file
selected, the original file size (ORIGINAL), the Data Diet file
size (DIETIZED), the compression percentage (%) (how much it is
compressed from the original size) and the time required to
perform the compression (SECONDS). Note that the SECONDS field
will only be filled in if you FLUSH the file or are in the
REALTIME compression mode (see the following explanations for
configuration details).
** Data Diet Demo **
Data Diet Demo operates in Realtime mode only. This means you're
going to get more of a slowdown than the method we suggest using,
which is Terminate mode (a real bummer - it's a demo!).
Additionally, the two boxes below the file size statistics
indicate the current state of the file. DECOMPRESSED selected
indicates that the file is a Data Diet file and is current