[comp.sys.tandy] command.com in RAM drive...

oolidjr@hubcap.UUCP (Joe Moll) (05/18/88)

Sorry to send so much, but I needed to straighten this one out.


>>From article <26530@clyde.ATT.COM>, by meb@floyd.ATT.COM:
>> What I have:      Tandy 1000EX
>>                   1-720K Floppy
>>                   1-360K Floppy
>>                   DOS 2.11
>> 
>> What I want to do:  I would like to copy command.com into a ramdrive and
>>                     have DOS look for it there instead of in drive A.
>>                     I have looked through my DOS manual and several DOS
>>                     books but I can't seem to find anything that covers
>>                     this topic.


Eric Wickberg writes in responce ...


>From: eric@umb.umb.edu (Eric Wickberg)
>Newsgroups: comp.sys.ibm.pc


>Looks like you are gonna have some problems in doing that.  The main
>problem is that when dos loads in (when you boot the A drive), it loads an
>image into memory, and, unfortunately, molds itself around the boot drive.  If
>you have noticed, the machine will access the A drive when exiting from some
>programs, and if it doesn't find the command.com in the drive it booted from,
>it tends to get very upset.  Now, in copying the command.com to the ramdrive
>AFTER dos boots, DOS is still gonna look for command.com in the A drive.  Now,
>you can't boot to the ramdrive, because DOS creates it.  So, as I see it, you
>have a pretty interesting catch-22.

>Lemme know if you find a solution to the problem..

>Good luck,

>Eric Wickberg

Well, I'm glad to say that you can copy COMMAND.COM into a RAM drive and
use it from there after boot.  I have done this on my Tandy
1000sx up until I recently bought my Hard-Card.

The trick is DOS's environment.  If you just type 'set' from a dos
prompt, it will report to you the current environment settings.  Setting
the environment variable 'COMSPEC' (yes, in CAPS) to the path where
your new copy of COMMAND.COM is now (i.e. C:\COMMAND.COM if your RAM drive is
drive C, which was my case) will cause DOS to make all accesses to
COMMAND.COM on the RAM drive, just as if you had booted from there.

Example:

In your autoexec ...

---
copy command.com c:
set COMSPEC=C:\COMMAND.COM    	<--	_Must_ be in caps.  DOS's Initial
					setting is in caps.  Will not overwrite
					if new one is in lowercase.
---

That is essentially what I had.  Worked great.  RAM drives are soooo
fast!!


Sorry Eric ....


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pkopp@potpourri.UUCP (Paul Kopp) (06/04/88)

in article <1653@hubcap.UUCP>, oolidjr@hubcap.UUCP (Joe Moll) says:
> Xref: gould comp.sys.ibm.pc:12923 comp.sys.tandy:640
>>>From article <26530@clyde.ATT.COM>, by meb@floyd.ATT.COM:
> Eric Wickberg writes in responce ...
>>From: eric@umb.umb.edu (Eric Wickberg)
>>Newsgroups: comp.sys.ibm.pc

[ all kinds of stuff deleted about command.com on a ram disk.]

I tried this too.  Well, actually, I was trying to move command.com out of
my root directory (same kind of thing).  To move this file, I had to do
TWO things.

1)   set COMSPEC = c:\dos\command.com      <---- in autoexec.bat  and

2)   command = c:\dos\command.com /p       <---- in config.sys (from
                                                 memory; I'm pretty sure
                                                 this is right.

Everything worked fine until I tried to format a floppy with the sys
option (format a:/s).  I kept getting prompted to place a disk with
command.com in drive a:.  I found the solution to this problem.  It
seems that in order to format a floppy with the "sys" option, the two
hidden files (msdos.sys and io.sys) needed to be in the same directory
pointed to by the above statements.  After I copied the two files over,
everything worked "as advertised." Now I'm not sure (because I haven't
tried it), but you're probably going to run into the same problem when
you move command.com to a ram disk.

-------------------------------------

Paul Kopp                                   The opinions (if any) expressed
Gould Inc., Computer Systems Division       are my own.
Fort Lauderdale, Florida
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