Unable to control a20 line - MHDD

[furacao]

Hi,

I am trying to run MHDD from a bootable CD in my HP Elitebook laptop but I have an error message indicating that the Memory extender cannot load along with the error "Unable to control a20 line".
Any idea how to fix it?

Thanks,

[HaQue]

wow, a blast from the past.
This is usually due to your boot config not quite right for the system. IIRC related to memory, possibly the Highmem.sys driver. Im sure if you google that you will find whats up with your system.
BTW is it the downloadable image you used or did you create it?

[furacao]

I used the bootable image from HDDguru website:
http://hddguru.com/download/software/mh ... 4.6iso.zip
When you mention that I must change my boot config, could you please confirm which one it is: in the boot CD or the PC?
Sorry if my question seems akwards but when I use the boot CD, I think I saw some info stating "Windows 98" OS and I have "Windows XP" on the PC, so I imagine I use files from the boot CD, and I do not know how to change any, as the only file I am able to see in the Boot CD is "readme.txt", where there is 1 line stating that this CD must be used as a boot one...

[HaQue]

Hi,
I didn't say "must" change it, I was saying it is possible.

What it looks like is the bootable CD is not fully compatible with your system.

What you may need to do is create a bootable CD that works on your system, and then add the MHDD program files to the image of the CD you created. There are various tutorials around the net for bootable cd creation.

some resources:
http://malthus.zapto.org/viewforum.php?f=89

post any follow-up to issues you have doing this.

cheers

[furacao]

Just tried your suggestion...
With Nero, I have created a Boot CD, using nt5boot.bin file as the boot sector and added the files contained in my XP CD, and the MHDD files.
The PC effectively boots with the CD, and Windows setup process loads files but when it gets to "Setup is starting windows", nothing happens, and I can hear that the CD drive is not accessed anymore: the only solution is to switch off the PC...
So looks like I am doing something wrong, any idea how to move forward?

[HaQue]

Hi,
Did you try the floppy version? http://files.hddguru.com/download/Software/mhdd32ver4.6floppy.exe

I am guessing you added the files from"mhdd32ver4.6archive.zip" ?

I think you should create a stand alone DOS floppy Boot disk, copy the above files to it, and in Config.sys add the line :

Code:

DEVICE=C:\DOS\HIMEM.SYS /M:1

You might need to change the number after the "M:" but probably not.. valid numbers are 1-14 and 16.

another option may be to disable Fast A20 Display and Fast Gate A20 in your BIOS.

[fzabkar]

I think you should create a stand alone DOS floppy Boot disk, copy the above files to it, and in Config.sys add the line :

Code:

DEVICE=C:\DOS\HIMEM.SYS /M:1

You might need to change the number after the "M:" but probably not.. valid numbers are 1-14 and 16.

FWIW, the HIMEM options are listed here:
http://support.microsoft.com/kb/135485

[furacao]

Hi,

Just to let u know what I have done to make it work, in case somebody faces the same issue.
I followed the procedure described here:
http://www.sevenforums.com/tutorials/46 ... reate.html,
which allowed me to create an DOS bootable USB key.
Then I just copied the unzip contents of "mhdd32ver4.6archive.zip", and launch MHDD with the /ENABLEPRIMARY option, after booting using the USB key.
Quite simple as I didn't even touch the config.sys file, the line with Himem.sys was "device=HIMEM.SYS /testmem:off".

Thanks for your help, as it pointed me in the right direction.

Cheers

[HaQue]

great news, I remember having a few fun times booting some systems with various things back in the day, Just have to try various things until something sticks