[comp.sys.ibm.pc] COMMAND.COM

john@moncol.UUCP (John Ruschmeyer) (12/14/86)

Forgive the cross-posting, but I've seen a similar question from a PCjr
user ont comp.sys.ibm.pc and hopefully this will answer both.

In article <159@ole.UUCP> yanagida@ole.UUCP writes:
>       I have  two problems  with  command.com on  my ATT  6300  running
>       MS-DOS v2.11.
>
>       First, I want to have command.com  load from my C: drive  instead
>       of A:.  I have tried putting the line:
>
>       SHELL=C:\COMMAND.COM /E:512 /P
>
>       in my config.sys file.  I also put the line:
>
>       SET COMSPEC=C:\COMMAND.COM
>
>       in my autoexec.bat file.   However, all that  does is give me  an
>       error message "Command search directory not found", or  something
>       like that, when I reboot.

Yes, it appears you are missing a parameter to the SHELL= line in
config.sys. You need to add C:\ to the line to tell command.com where to
look when it needs to reload tiself from disk.

In your case, the chrrect line from config.sys should be:

	SHELL=C:\COMMAND.COM C:\ /P

or even

	SHELL=A:\COMMAND.COM C:\ /P

since you are booting from A:. BTW, Is C: a hard disk or a ramdisk? It
would seem to me that if it were a ramdisk, you couldn't set the SHELL in
config.sys since there wouldn't be a copy of command.com in C:\ yet. On the
other hand, it C: is an HD, why boot from A:?

Note on COMSPEC under MS-DOS 2.x-
 
There is a bug in DOS 2.x which often clobbers the COMSPEC variable. This
will cause DOS to ask for a valid command.com in drive A:, even though you
have set COMSPEC=C:\COMMAND.COM in your autoexec.bat.
 
PC Tech Journal (and others) have developed programs to get around this
problem. Try checking local BBS's for a program called (I think) COMFIX.

>       Second, I would really like to increase my environment space so I
>       can set a reasonable PATH variable.  Has anyone else  tried this?

Yes, but if you're running 2.11, you can't do it the way you are trying to.
The /E parameter to command.com was not added until DOS 3.1. For DOS 2.x,
you need to patch command.com (sorry I don't have the address handy) or use
one of the programs which dynamically expands the environment size.
(Someone posted a program named ENVSIZE.COM a few months back.)

Hopefully, this is of some help.

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figlik@ihlpl.ATT.COM (Jim Figlik) (12/28/88)

In article <2856@aplcomm.jhuapl.edu> you write:
>
>	Just out of curiosity, has anyone experienced the error:
>
>	"Invalid COMMAND.COM
>	
>	COMMAND.COM Not found - System Halted"
>
>	on their PC's?  I have a Tandy 1000 myself.  I think it is a
>	hardware problem, however, since I have and OLD 1000, (not
>	an SE/TX/ etc, but before them) and have made modern modifications.
>	COMMAND.COM is on my hard drive, and COMSPEC IS set to find
>	it, but I get the error anyway.  I also have an accelerator card,
>	to make it a 286 machine, and I believe this to be the problem,
>	but I can't be sure.  The error only occurs when I leave
>	some programs, and try to return to MS-DOS.  
>	It happens in one other game, too, Leisure Suit Larry II,
>	in the middle of the game.  The screen blanks out, and the error
>	message comes up.
>
>	Any ideas of where this error might come from, or how to 
>	fix it?

I believe that you have two problems here. The first is "Invalid
COMMAND.COM". This occurs if you've booted off of one version of 
DOS and then try to execute another version.

The second problem is DOS' inability to find COMMAND.COM. The
version pointed by COMSPEC is giving you the above error. Thus,
my opinion is that you are booting from a COMMAND.COM that is
different from the  one pointed to by the COMSPEC variable. The
obvious solution is to find where the boot version of COMMAND.COM
is. You can force it to be the same as COMSPEC by using the SHELL
variable in your "config.sys" file (e.g. SHELL=C:\DOS\COMMAND.COM /P).

While I'm not familiar with the Tandy accelerator card, I have
seen some accelerator software interfere with "normal" use of a
machine. Have you tried running the applications that have the
problem without the accelerator card? Check the software (if any)
that the accelerator uses and any startup parameters.

Jim
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