Path: utzoo!utgpu!water!watmath!clyde!att!ttrdc!ttrde!kad
From: kad@ttrde.UUCP (Keith Drescher)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Shell command question
Keywords: shell msdos autoexec.bat
Message-ID: <616@ttrde.UUCP>
Date: 2 Jun 88 13:38:11 GMT
References: <1102@cod.NOSC.MIL>
Reply-To: kad@ttrde.UUCP (Keith Drescher)
Organization: AT&T End User Organization,  Skokie, Ill.
Lines: 54

In article <1102@cod.NOSC.MIL> desmond@cod.NOSC.MIL (J. Desmond) writes:
>I've noticed that using the shell= command in the config.sys file
>inhibits execution of the autoexec file on my Zenith 248.  Is this
>true of other clones?  Is there a way to inhibit the inhibition?
>Even shell=command.com does it.
>-J M Desmond
>desmond@nosc.mil

I boot with "shell=command.com /E:1024 /P" and it reads autoexec.bat.
I tried leaving the /P off, and it did not.

My MS-DOS manual (AT&T version 3.2) says 
"The /P option tells MS-DOS to make the processor permanent."

No mention of the executing autoexec.bat thing.  HOWEVER, I checked
two PC-DOS manuals:

PC-DOS 3.2 says:
"/P causes COMMAND.COM to execute AUTOEXEC.BAT once it gets installed."

PC-DOS 3.3 says:
"/P causes COMMAND.COM to remain loaded and to execute AUTOEXEC.BAT
once it is installed."

I noticed that saying "exit" to the first loaded version of command.com
causes the pc to crash when /P is not specified (as would  be expected,
it exited, as told.  The /P flag tells command.com to ignore that
command.

The MS-DOS manual also mentions that the /E and /P options may not work
with other command processors.

To wrap it up, to boot with a larger environment AND execute command.com
you need to say:
shell=command.com /E:xxxxx /P
where xxxxx is a decimal number specifying the environment size in bytes.
You don't need to modify command.com to get this effect.


Hope this helps someone, somewhere.

Keith Drescher

P.S.  Prior to MS-DOS version 3.2, (at least my 3.1 manual doesn't mention it)
      the /E flag didn't exist, so the only way to increase the environment
      size was to modify command.com.  Just like prior to 3.3, there was no way
      to have ECHO OFF be the default unless you hacked it.  

      
-- 
Keith Drescher (kad@ttrdc)          	   | ... You can check out any      
AT&T                                       | time you like - but you can
Computer Systems Division, Skokie, Il.     | never leave ...              
PATH: ...!ihnp4!ttrdc!kad                  |          - Hotel California