Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site decwrl.DEC.COM
Path: utzoo!linus!decvax!decwrl!dec-rhea!dec-comet!fulton
From: fulton@comet.DEC (Cathy Fulton, CXO Technical Training)
Newsgroups: net.micro.pc
Subject: MS-DOS Environment Size
Message-ID: <1107@decwrl.DEC.COM>
Date: Thu, 13-Feb-86 02:36:26 EST
Article-I.D.: decwrl.1107
Posted: Thu Feb 13 02:36:26 1986
Date-Received: Fri, 14-Feb-86 06:38:01 EST
Sender: daemon@decwrl.DEC.COM
Organization: Digital Equipment Corporation
Lines: 36

Over the last six weeks or so I have seen several questions on both usenet
and ARPANET about DOS environment size.  This subject was very important to 
me, as I run MANY different applications under MS-DOS which require much use
of SET and PATH in autoexec.bat.  I frequently had to play games in order to
pare my environment size down to the default 160 bytes.

Well, thanks to the Feb 26, 1986 edition of PC Magazine, I no longer have
to worry about receiving the "Out of environment space" error message.  Here is
the info I was so glad to get:

   "...PC-DOS 3.1 does have a way to enlarge the environment.  What you must
   do is use a CONFIG.SYS file to specify COMMAND.COM as a SHELL.  This is done
   with a line in the CONFIG.SYS file that reads

      SHELL=COMMAND.COM /P /E:62

   Without the /P parameter, COMMAND.COM would not execute the AUTOEXEC.BAT
   file.  (This is something that goes back to DOS 2.0.)  The /E parameter is
   new with Version 3.1.  The value following the colon is the number of 16-byte
   paragraphs reserved for the environment.  The default is 10 paragraphs
   (160 bytes) and the maximum is 62 (992 bytes). (If you set the value below 10
   or above 62, COMMAND.COM will use the default of 10.)..."

As noted above, this only works with DOS 3.1.  If you are running version 2.x
and want to upgrade to 3.1:

   "...boot up the machine with the 3.1 DOS diskette in drive A:, run the SYS
   command [ex.- "SYS C:"], copy over COMMAND.COM, and copy all the other DOS
   files..."

I successfully accomplished both of the above tasks (MS-DOS 2.1 to 3.1, and
increase of environment size to 992 bytes) today on my Zenith Z-151.


...decvax!decwrl!dec-rhea!dec-comet!fulton
fulton%comet.DEC@decwrl