Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!njin!princeton!udel!gatech!uflorida!umd5!vrdxhq!daitc!otishq!guardian
From: guardian@otishq.UUCP (Harry Skelton)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Another twist on DOS environment sizes.
Summary: Environment differs between dos versions
Message-ID: <111@otishq.UUCP>
Date: 3 Jun 88 14:51:30 GMT
References: <3057@crash.cts.com>
Organization: American Automobile Assc., Falls Church, Va
Lines: 40

In article <3057@crash.cts.com>, rgale@pnet01.cts.com (Ryan Gale) writes:
> > Because, as mentioned in an earlier article today, specifying
> >   shell=command.com /e:nnnn
> > in config.sys prevents execution of autoexec.bat.
> 
> Oh?  My CONFIG.SYS includes the line
>         SHELL=C:\COMMAND.COM /E:1024 /P
> and AUTOEXEC.BAT runs just fine.  [This is PC-DOS 3.3.]
> 

If you have dos version 3.1, you will have to specify a maximum size of
2k only.  beyond that you will crash your system.  (specs below).  3.2
has the limit removed but still has problems with some programs and 
utilities trying to read the environment (command.com will crash with a
+2k environment.  3.3 is fine but some programs don't understand the
environment size.

summary:

3.0: Have to fix an offset in command.com MKS's init.exe with a login of
dos can fix this but I have not tested it with many programs.

3.1: environment set in blocks of 16bytes.  Max is 2k w/possible 1k on
generic versions of MS-DOS 3.1 (tandy and wyse is bad for this).

3.2: environment size fixed (most versions of MS-Dos - depends on bios).
Buff size is 16bytes (i.e. /E:10 = 160 bytes).  Sometimes command.com
gets confused beyond 25 if a tsr is loaded prior to command.com.

3.3 environment size correct. Buff size is in BYTES!  /E:2048 = 2k environment.

I think this is correct and has worked for my machine.  I run IBM-DOS versions
and have had no problems with the above.
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