IBM Personal Computer Disk Operating Sysetm (DOS) Environmental Variables
@ECHO OFF
SET THIS_VARIABLE_IS=EXACTLY_38_BYTES_LONG
IF NOT '%THIS_VARIABLE_IS%'=='EXACTLY_38_BYTES_LONG' GOTO ERROR
SET THIS_VARIABLE_IS=
SET DOS=IBM_PC_33
SET MON=VGA
SET ADRV=1200
SET BDRV=1440
GOTO NEXT
:ERROR
ECHO * ERROR * * * ERROR * * * ERROR * * * ERROR *
ECHO ---------------------------------------------
ECHO Your system does not have enough environment space available 
ECHO to execute this batch program.
ECHO ---------------------------------------------
ECHO If your DOS version is 3.0 or less, you will have to patch 
ECHO COMMAND.COM to get a larger environment.  DOS versions 3.1 
ECHO and up can enlarge the environment with a CONFIG.SYS line:
ECHO.
ECHO     SHELL=C:\COMMAND.COM /P /E:###
ECHO.
ECHO For DOS 3.1, replace ### with the number of 16-byte paragraphs
ECHO you want in the environment.  For 3.2 and up, replace ### with
ECHO the actual number of bytes you want.  If your COMMAND.COM is
ECHO not in the root directory of C:, replace C:\COMMAND.COM with
ECHO the actual location of COMMAND.COM.  The change will take effect
ECHO after you reboot your computer.
ECHO.
GOTO END
:NEXT
SET
ECHO Environment variables OK -- rest of batch program goes here.
:END