Hard Disk Management: Level 2

BATCH FILES
-----------
These are user created files that have the extension .BAT

The file itself contains lines of DOS commands.  Some think of these
files as "macros".  They can be created with an ASCII text editor
including the built in EDLIN editor (see below), or can be created from "the
console" (keyboard) via COPY CON.

These are very useful for program startups.

Use the TYPE command to view the contents of a batch file:

C:\>TYPE 123.BAT

   c:\
   cd\lotus
   123
   cd\
   cls

Use the PRINT command to print out the contents of a batch file:

C:\>PRINT AUTOEXEC.BAT

The PRINT command is like the TYPE command except it is an external DOS
command and send output to the printer instead of the screen.  Another
approach using redirection discussed earlier would be:

C:\>TYPE AUTOEXEC.BAT >PRN


AUTOEXEC.BAT
------------
This user created, optional batch file is sought out by DOS when the
system is BOOTed.  If this file is on the BOOT disk, DOS will
AUTOmatically open it and EXECute it.

This is outstanding way to automate the execution of certain DOS
commands like DATE, TIME, PATH, PROMPT, etc - which should be done
EVERY time the system is booted.

EX:

          date
          time
          path c:\;c:\dos;c:\batch;c:\utility
          subst e: c:\dbase\dbfiles
          prompt $p$g
          cls
                                                                                






CONFIG.SYS
----------
This too is an ASCII file created and viewed like AUTOEXEC.bat.  It
also is optional and is sought out by DOS when the system is BOOTed. HOWEVER,
the command lines that this file uses ARE NOT DOS type commands found in .BAT
files.  Rather, these are special CONFIGuration SYStem commands.

CONFIGuration SYStem commands are needed to define certain hardware
parameters.  For example, if your system uses special size disk drives,
extra printers, extra modems, extra input devices (joysticks, mouse),
RAM disks, etc.

EX:  CONFIG.sys

        FILES = 20
        BUFFERS = 15

In this example, FILES = 20 means that DOS will allow up to 20 files opened
simultaneously.  If this line were not present in CONFIG.SYS, DOS would only
allow up to 7 files.  Do we need up to 20?  Certain programs (dBASE,
Accounting, etc) state early in their manuals that this parameter needs to be
set at 20 for the software to operate correctly.

The BUFFERS = 15 defines a staging area within RAM for portions of files that
are not on the screen yet.  For example, in an Accounting program if you told
the computer to bring up the last 10 invoices entered, it would display these
10 invoices.  However, unknown to you it actually took the last 30 invoices in
anticipation that you would want to see them right away also.  The extra 20
that the system brought into RAM are sitting within the BUFFERS.  DOS allows
this and does this as a way to speed up the system.  Items that are sitting in
RAM can be accessed seemingly instantly versus items that must be sought from
a disk.

If not told, DOS automatically sets BUFFERS to 3.  If BUFFERS are so useful,
why not set them to their maximum of 99?  The reason is that DOS is guessing
which information you will need next.  If it guesses wrong - for example the
next invoice you wish to look at is 1500 ago, it must first check all the
BUFFERS before realizing that it will have to go to the disk to retrieve the
needed information.  It actually slows the process down in this case.  Most
purchased software will note if this command is needed and what to set it to.
BUFFERS = 15 is a common level to operate at.


EDLIN
-----
Edlin is a LINe EDitor supplied with the DOS disks.  It is a very basic word
processor that allows the creation and editing of Batch Files including
AUTOEXEC.BAT and the CONFIG.SYS file.  These files are like documents that the
computer reads and interprets.  Each line of these files contains a single
thought for the computer.  EDLIN is a device to create these documents.
                                                                                





To enter the EDLIN environment you type the word EDLIN followed by the name of
the file you wish to create or edit:

        C:\>EDLIN CONFIG.SYS

An asterisk will appear:

  *

You will type the letter  I  and press enter to go into the Insert mode:

  *I

The computer responds with:

       1:*

This 1 refers to line 1 of the CONFIG.SYS you are now creating.  You will now
just type each line and press enter.  When finished you will press the <F6>
key to return to the furthest left asterisk:

       1:*FILES = 20
       2:*BUFFERS = 15
       3:<F6>
  *

At this asterisk you will now type  E  and press enter to  End the process and
save what you just created:

  *E

C:\>

Other EDLIN commands from the left most asterisk:

  *L      - this would List on the screen the entire contents of the
            file being edited

  *3D     - this would delete line #3 from the file

  *4I     - this would allow inserting a new command beginning at line #4

  *5      - this would allow making changes to line #5


EDLIN is adequate for creating and editing small Batch type files.  We saw
earlier that there is another technique for creating these files utilizing the
COPY CON  command.  It is even more limited than EDLIN.



BACKUP and RESTORE
------------------
Periodically the entire hard drive or at least the subdirectories
containing data files should be BACKed-UP onto floppies or tape for
safe storage in the event of a hard drive crash or accidental erasure.

Should that happen, the files are then simply RESTOREd.
                                                                                





DOS provides two commands to accomplish this - BACKUP and RESTORE
commands.  Unfortunately, these are slow and problematic.  The world is
full of third party alternatives that are far superior in speed, ease
of use, data compression, and ability to incorporate into batch files
so the operator only need to "kick-off" a batch file and have a supply
of floppies nearby to complete.

EX: Using DOS commands:

     C:\>BACKUP C:\lotus\*.wks A:  /S  /M

"A" is the DESTINATION drive
 C:\lotus  is the SOURCE directory
 *.wks   specifies any files with an extension  .wks  (worksheet files)

 /S      specifies any Subdirectories beneath \LOTUS directory
         (that contain *.wks files)

 /M      only the files that have been Modified since Last BACKUP (using the
         same disk set as last used during the BACKUP)


NOTE: Have a supply of disks for the "A" drive ready.  These floppies do not
have to be formatted.  If more than 1 is required, be sure to number in
sequence.  This process will erase whatever used to be on the disk.

Now, if the files need to be restored to the hard drive due to failure
or erasure:   Start out with "disk #1" in the "A" drive.

     A:\>RESTORE A: C:\lotus\*.wks  /S  /M

"A" is now the SOURCE

 /M     only files Modified or Deleted since they were backed up


These commands were designed for emergency situations.  It is better than
nothing.  Many wish to use them as a way to transfer a large group of files
from one machine to another.  This will only work if the version of DOS on
each machine is identical.

Another problem is that you end up with a very large number of disks.  There
is no data compression (which most competing products provide) which results
in up to 50% fewer backup disks.

A final hazard:  If you end up with 20 disks, and disk number 10 is lost or
destroyed, you may never be able to access disks 11-20 or 1-9.  The 20 disk
set is like one continuous floppy disk.  By destroying 1 disk, it is like you
destroyed the giant continuous floppy.  This is not true of competing products
like FASTBACK, PCTOOLS or NORTON UTILITIES.
                                                                                





XCOPY
-----
Beginning with DOS 3.2, the XCOPY command is a useful hybrid of the COPY
command and the BACKUP/RESTORE mess.  It addresses the issue that COPY cannot
copy more files than a disk can hold.  But, XCOPY cannot copy a single file
that is larger than a single disk like the BACKUP command can.


C:\>XCOPY C:\*.* a:  /S /M /D:mm-dd-yy


The options:   /S    - includes all subdirectories hung from the current one
                       (in the case shown we are in the root directory)

               /M    - includes only files that have been modified since the
                       last XCOPY was performed

               /D:mm-dd-yy   - include only files with a date greater or
                               equal to the one specified


XCOPY is:   - Faster than the COPY or BACKUP commands
            - Able to transfer entire directories like BACKUP can
            - Copy files selectively by modification status or date
            - Able to use the COPY command (which is DOS version independent)
              to copy individual files at a later date - unlike BACKUP
            - Unable to copy single files that are larger than a single disk
              (BACKUP is able to do this - remember the 1 continuous disk
               concept)
            - Target disks must be formatted


HARD DISK ORGANIZATION PRINCIPALS
---------------------------------

     1. Put only directories in the Root directory except;
        Command.com, Config.sys, Autoexec.bat

     2. Use many batch files.  Put them in a \BATCH subdirectory

     3. Keep the PATH command short in autoexec.bat
        PATH = c:\DOS;c:\BATCH;c:\UTILITY

     4. Keep the directories sorted (use third party software tools)

     5. Defragment files on a regular basis - use some third party
        software; PC-TOOLS, NORTON UTILITIES, VOPT, etc



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