[Grub4dos-devel] A20 gate cannot be turned off with 0.4.2pre11 and later on newer Laptops

[Quinn Plattel]

I have been testing grub4dos with dos based images utilising himem.sys.

On Dell D610's, IBM ThinkPad T23/T30/T41, the A20 gate is successfully
turned
off with any version of grub4dos.

On IBM ThinkPad T43/T60/T60p, the A20 gate fails to turn off with version
0.4.2pre11 onwards. This fails even when using the --disable-a20 switch on
the chainloader command.

A temporary workaround is to either use or chainload 0.4.2pre10 or earlier.

I've looked at the source differences between 0.4.2pre10 and 0.4.2pre11 and
it looks like there is a section where the programmer decides to leave the
A20 gate on permanentely. I don't know for sure if that is the problem.

Are there any fixes/patches for this problem?

Quinn
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[Bean]

The 0.4.2 series is too old, please try the latest version at:

http://download.gna.org/grub4dos/

The 08-27 version may have some bug, if it fails, try ealier versions.

--
Bean

[Quinn Plattel]

I started out with 0.4.3 r52 (2003-08-23) - that's where I started
seeing the problem. I then
tried different versions until I found a version that worked.
It looks like it broke between 0.4.2pre10 and 0.4.2pre11. the later
versions I tried were 0.4.2 and 0.4.3 r52 (2003-08-23).

Suggestions?

Quinn

[Bean]

You mean none of the 0.4.3 versions work ?

On 8/31/07, Quinn Plattel <qie...@gmail.com> wrote:
> I started out with 0.4.3 r52 (2003-08-23) - that's where I started
> seeing the problem. I then
> tried different versions until I found a version that worked.
> It looks like it broke between 0.4.2pre10 and 0.4.2pre11. the later
> versions I tried were 0.4.2 and 0.4.3 r52 (2003-08-23).
>
> Suggestions?
>
> Quinn

_______________________________________________

[Quinn Plattel]

Of the 0.4.3 versions, I have only tested the r52 version. I will try
more of the 0.4.3 versions to see if any of them worked and let you
know the test results.

Quinn

[Quinn Plattel]

Ok,

After a weeks sick leave, I managed to take a day and test the various
versions of grub4dos 0.4.3 on an IBM Thinkpad T43.
I have tested every single version of grub4dos that was available
on this site: http://download.gna.org/grub4dos/

Every single version of the 0.4.3 series as well as the official 0.4.2
and 0.4.2pre11 fails turning off the A20 gate on this machine.
But again, if I test versions 0.4.2pre10 and before, the A20 gate
turns off properly
and himem.sys is able to control the A20 line.

The 0.4.3 series also fail turning off the A20 gate on IBM ThinkPad
T60, T60p and X60s machines, but not on IBM ThinkPad T30, T23, and T41
machines.

0.4.2pre10 seems to be the last version that is able to turn off the
A20 gate on all the machines I have access to.

I hope these tests help you debug the problem and I am willing to help
you do more testing if need be.

Quinn

[Quinn Plattel]

Ok,

After a weeks sick leave, I managed to take a day and test the various
versions of grub4dos 0.4.3 on an IBM Thinkpad T43.
I have tested every single version of grub4dos that was available
on this site: http://download.gna.org/grub4dos/

Every single version of the 0.4.3 series as well as the official 0.4.2
and 0.4.2pre11 fails turning off the A20 gate on this machine.
But again, if I test versions 0.4.2pre10 and before, the A20 gate
turns off properly
and himem.sys is able to control the A20 line.

The 0.4.3 series also fail turning off the A20 gate on IBM ThinkPad
T60, T60p and X60s machines, but not on IBM ThinkPad T30, T23, and T41
machines.

0.4.2pre10 seems to be the last version that is able to turn off the
A20 gate on all the machines I have access to.

I hope these tests help you debug the problem and I am willing to help
you do more testing if need be.

Quinn

On 01/09/2007, Quinn Plattel <qie...@gmail.com> wrote:

[Bean]

Hi,

Thank you very much for your testing, i will look into this problem
when i get time.

--
Bean

[Quinn Plattel]

Hi,

I have now tested 2007-10-12 to 2007-10-17 versions. The A20 gate
problem seems to have gone away now on the IBM T60 laptops. The
2007-10-17 version freezes though before showing menu.lst.

Good job!

I'll let you know if the IBM T43 laptops have also been fixed when I
get the time.

Quinn

[Quinn Plattel]

It looks like IBM Thinkpad T43's also show success but only when I use
the "map --a20-keep-on=0" command.
The same goes for the IBM Thinkpad T60's.

Quinn