bradley.grigor@canremote.uucp (BRADLEY GRIGOR) (12/16/89)
Re: INVALID COMMAND.COM SYSTEM HALTED U>I run PCDOS 3.3, and this happens for me too. But very seldom, maybe U>once every other month. I suppose it has to do with the non-resident U>part of command.com (in high memory) being written over by an U>application, which necessitates it to be reloaded from disk. For some This is my suspicion too. U>reason, DOS seem not to find it. I haven't looked into this, because U>it's no big problem for me. Could it have something to do with U>redefining SWITCHAR to '-'? I do that on my machine. Maybe it means U>DOS cannot find the path given by the COMSPEC env. variable? I have not redefined the SWITCHAR but I have added 64K and patched my system for 704K. I first noticed the "INVALID COMMAND.COM" after making that change. Any clues here? Brad Grigor Mainline Technologies bradley.grigor@canremote.uucp --- ~ EZ-Reader 1.21 ~ Give me a good 84-key keyboard anyday!
bl@infovax.UUCP (Bj|rn Larsson) (12/19/89)
In article <89121614031714@masnet.uucp> bradley.grigor@canremote.uucp (BRADLEY GRIGOR) writes: >Re: > INVALID COMMAND.COM > SYSTEM HALTED >U>it's no big problem for me. Could it have something to do with >U>redefining SWITCHAR to '-'? I do that on my machine. Maybe it means >U>DOS cannot find the path given by the COMSPEC env. variable? > > I have not redefined the SWITCHAR but I have added 64K and patched > my system for 704K. I first noticed the "INVALID COMMAND.COM" after > making that change. Any clues here? > I do that too, using QEMM (Quarterdeck Extended Memory Manager). How- ever, I had this problem long before I started to use the 386 memory mapping features (at least I'm 98.5% certain about this). ON the other hand it sounds interesting - those re-mapped 64k, above 640k, is where the memory resident copy of COMMAND.COM will be. But the fact that the error is 'cannot find it' indicates it is not found *on the disk*. Not finding it in memory is normal, and causes the re-load from disk. For what it's worth...:-> Bjorn -- ====================== InfoVox = Speech Technology ======================= Bjorn Larsson, INFOVOX AB : ...seismo!mcvax!kth!sunic!infovax!bl Box 2503 : bl@infovox.se S-171 02 Solna, Sweden : Phone (+46) 8 735 80 90
Devin_E_Ben-Hur@cup.portal.com (12/20/89)
The problem with "INVALID COMMAND.COM -- SYSTEM HALTED" does have to do
with attempting to reload the transient portion of COMMAND.COM from disk.
The problem is that the resident portion of COMMAND.COM *ignores* the COMSPEC
environment variable. If your shell is loaded from other than the root
directory of the boot drive, the transient reload will fail unless you
specify the correct re-load path as a parameter to COMMAND.COM in the initial
SHELL= line of CONFIG.SYS. So, if your COMMAND.COM is located in a
directory named DOS on drive C, your CONFIG.SYS should have a line like:
SHELL=C:\DOS\COMMAND.COM C:\DOS /P <other switches>
^^^^^^ -- this tells it where to reload from.
Note that, when the reload path is specified in the shell= line, there
is no need to set comspec in your autoexec.bat, command.com will automatically
make "COMSPEC=<load-path>\COMMAND.COM" the first line of your environment.
Devin_Ben-Hur@Cup.Portal.Com
...ucbvax!sun!portal!cup.portal.com!devin_ben-hurleonard@bucket.UUCP (Leonard Erickson) (12/24/89)
Devin_E_Ben-Hur@cup.portal.com writes:
<The problem with "INVALID COMMAND.COM -- SYSTEM HALTED" does have to do
<with attempting to reload the transient portion of COMMAND.COM from disk.
<The problem is that the resident portion of COMMAND.COM *ignores* the COMSPEC
<environment variable. If your shell is loaded from other than the root
<directory of the boot drive, the transient reload will fail unless you
<specify the correct re-load path as a parameter to COMMAND.COM in the initial
<SHELL= line of CONFIG.SYS. So, if your COMMAND.COM is located in a
<directory named DOS on drive C, your CONFIG.SYS should have a line like:
<
<SHELL=C:\DOS\COMMAND.COM C:\DOS /P <other switches>
< ^^^^^^ -- this tells it where to reload from.
<Note that, when the reload path is specified in the shell= line, there
<is no need to set comspec in your autoexec.bat, command.com will automatically
<make "COMSPEC=<load-path>\COMMAND.COM" the first line of your environment.
I must disagree with you. Some versions of DOS may act this way, but not all.
I ran a two disk system for *months* with comspec pointing to a copy of
COMMAND.COM in a ramdisk. And none of the reloads failed. There was no SHELL
line in my CONFIG.SYS, just a SET COMSPEC=C:\COMMAND.COM in my
AUTOEXEC.BAT. I know that reloads were occuring, because I'd had to set up
the ramdisk so I didn't get prompted for "inesrt disk with COMMAND.COM"
all the time.
Do note that DOS will cheerfully use a copy of command.com in the *current*
directory for reloading. So it pays to make sure that you only have *one*]
copy on your HD!
--
Leonard Erickson ...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters." -- Solomon Short