🚀 go-pugleaf

In article <410@mhuxi.UUCP>, v1b@mhuxi.UUCP (davis) writes:
> 
> For DOS 3.1, an undocumented feature of the SHELL command is used
> in the CONFIG.SYS file:
> 
> shell=drive/pathname_of_command_processor drive/path_to_command_process
>       /p/e:number_of_16_byte_paragraphs
> 
>       where:  10<paragraphs<63
> 
> Example, giving 480 byte environment space:
> 
> shell=c:\command.com c:\/p/e:30
> 
> I'd like the address to patch in DOS 3.1, since the SHELL feature is undoc-
> umented, and hence unsupported.
> 
> Max S. Robin

I don't know where you were looking, but on page 4-25 of the DOS 3.1 manual
(DOS manual, not the Dos Technical Reference) the shell command IS documented.
This was also documented in the 2.1 manual as well.

What isn't documented, is the flags to command.com which are used.  The only
flag documented for command.com is the 'c' option, which is documented in the
section "Executing Commands From Within an Application" in the DOS Technical
reference manual (Chapter 8 for 3.1).  The 'p' option tells command.com to
stay resident, (ignore the 'exit' command, among other things), and I believe
this also tells command to read the autoexec.bat file.  The 'e' option, (which
is only available in 3.x),  sets the default environment size as you have
pointed out.

The second option to the shell command (actually is just passed to command
like the rest of the stuff on this line), tells where command is to re-load
the transient portion from.  This appears in COMSPEC too, so other applications
can use this info.  You should be able to put a path to a ramdisk here,
then command will re-load from the ramdisk. (No guarantees, since I don't use
a ramdisk).

Hope this clears up some confusion.  I prefer to use the 'undocumented'
option in the shell command in place of patching command.com.

If only Microsoft had 'developers' like Commodore does with its Amiga...

-- 

Bill Marsh, Naval Ocean Systems Center, San Diego, CA
{arpa,mil}net: bmarsh@nosc
uucp: {ihnp4,akgua,decvax,dcdwest,ucbvax}!sdcsvax!noscvax!bmarsh

"If everything seems to be coming your way, you're probably in the wrong lane."