ELKS on Laptops

ELKS on Laptops

[Juanjo Marín]

Hi there,

I've found a page about ELKS on 286 laptops. It's on

http://tuxmobil.org/286_mobile.html

I think that maybe it's a god idea to get referenced this link on ELKS pages.

Cheers,

      Juanjo

768k XT?

[Dan Olson]

Hopefully someone knows, I have a Samsung XT clone that has 3 banks of
256k chips, so that would mean a total of 768k or memory.  The BIOS memory
check reports 640k, so I'm wondering if there really is 768k available
somehow, or if it was just cheaper to use 256k chips and leave a few k
unused.  Has anyone ever run into this before?  Is anyone familar with any
other boards that allowed the use of 256k parts in place of the 64k chips
in order to add some upper memory?  Does anyone have any DOS utilities or
ELKS utilities that would test for upper RAM even though the BIOS says
it's not there?  Thanks.

	Dan

Re: 768k XT?

[Chad Page]

	Use DOS debug to see if there's memory between segments a000 and
b000/b800, depending on the video type.  It might also have an MMU of some
sort, but that would be rather unlikely.

	- Chad


On Tue, 10 Jun 2003, Dan Olson wrote:

> Hopefully someone knows, I have a Samsung XT clone that has 3 banks of
> 256k chips, so that would mean a total of 768k or memory.  The BIOS memory
> check reports 640k, so I'm wondering if there really is 768k available
> somehow, or if it was just cheaper to use 256k chips and leave a few k
> unused.  Has anyone ever run into this before?  Is anyone familar with any
> other boards that allowed the use of 256k parts in place of the 64k chips
> in order to add some upper memory?  Does anyone have any DOS utilities or
> ELKS utilities that would test for upper RAM even though the BIOS says
> it's not there?  Thanks.
> 
> 	Dan
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-8086" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: 768k XT?

[Dan Olson]

I could look for documentation I guess, but I'm not familar enough with
DOS debug to know how to test for memory (I presume just writing to that
address and seeing if there's anything there afterward).  I have a VGA
card in it now but could use anything I suppose.  It's most likely that
the memory is linear but that may not be the case.  I was also wondering
if there might be a register somewhere that turn the RAM on/off.

	Dan


On Tue, 10 Jun 2003, Chad Page wrote:

>
> 	Use DOS debug to see if there's memory between segments a000 and
> b000/b800, depending on the video type.  It might also have an MMU of some
> sort, but that would be rather unlikely.
>
> 	- Chad
>
>
> On Tue, 10 Jun 2003, Dan Olson wrote:
>
> > Hopefully someone knows, I have a Samsung XT clone that has 3 banks of
> > 256k chips, so that would mean a total of 768k or memory.  The BIOS memory
> > check reports 640k, so I'm wondering if there really is 768k available
> > somehow, or if it was just cheaper to use 256k chips and leave a few k
> > unused.  Has anyone ever run into this before?  Is anyone familar with any
> > other boards that allowed the use of 256k parts in place of the 64k chips
> > in order to add some upper memory?  Does anyone have any DOS utilities or
> > ELKS utilities that would test for upper RAM even though the BIOS says
> > it's not there?  Thanks.
> >
> > 	Dan
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-8086" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
>
>

RE: 768k XT?

[Riley Williams]

Hi Dan.

 > Hopefully someone knows, I have a Samsung XT clone that has
 > 3 banks of 256k chips, so that would mean a total of 768k or
 > memory. The BIOS memory check reports 640k, so I'm wondering
 > if there really is 768k available somehow, or if it was just
 > cheaper to use 256k chips and leave a few k unused.

I don't know that particular box, so can't comment there, but...

 > Has anyone ever run into this before?

I've run into similar - in my case, a Kyoshui XT with 4x256k
mapped as 640k of normal RAM and 384k of EMS RAM (permanently
in the D0000-DFFFF address range.

Technically, it's possible that one of the 256k banks has one of
the address pins permanently tied either high or low, and thus
that the extra 128k isn't mapped anywhere as a result.

 > Is anyone familiar with any other boards that allowed the use
 > of 256k parts in place of the 64k chips in order to add some
 > upper memory?

Other than the above, no.

 > Does anyone have any DOS utilities or ELKS utilities that
 > would test for upper RAM even though the BIOS says it's
 > not there?

As far as RAM above 1M is concerned, the XT processors don't
support it.

Best wishes from Riley.
---
 * Nothing as pretty as a smile, nothing as ugly as a frown.

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RE: 768k XT?

[Dan Olson]

>  > Has anyone ever run into this before?
>
> I've run into similar - in my case, a Kyoshui XT with 4x256k
> mapped as 640k of normal RAM and 384k of EMS RAM (permanently
> in the D0000-DFFFF address range.

Interesting, it's nice to know that someone else thought of such a thing,
and to know there there is always a chance.  Is there any indication
(durring the memory check or by any other method) that this memory is
present?

 > Technically, it's possible that one of the 256k banks has one
of > the address pins permanently tied either high or low, and thus
> that the extra 128k isn't mapped anywhere as a result.

Sure, that's actually what I suspect to be the case.

>  > Does anyone have any DOS utilities or ELKS utilities that
>  > would test for upper RAM even though the BIOS says it's
>  > not there?
>
> As far as RAM above 1M is concerned, the XT processors don't
> support it.

Sure, I'm just refering to the memory between 640k and 1M, if present.

	Dan

Re: 768k XT?

[jb1]

On Tue, 10 Jun 2003, Dan Olson wrote:

> Hopefully someone knows, I have a Samsung XT clone that has 3 banks of
> 256k chips, so that would mean a total of 768k or memory.  The BIOS memory
> check reports 640k, so I'm wondering if there really is 768k available
> somehow, or if it was just cheaper to use 256k chips and leave a few k
> unused.  Has anyone ever run into this before?  Is anyone familar with any
> other boards that allowed the use of 256k parts in place of the 64k chips
> in order to add some upper memory?  Does anyone have any DOS utilities or
> ELKS utilities that would test for upper RAM even though the BIOS says
> it's not there?  Thanks.
> 
> 	Dan

Alan Cox (and maybe others) actually answered your question about running
ELKS on this machine last November when you were trying to run it on a
512K machine: ELKS is compiled to use exactly 640K; you *might* be able to
use more if you re-compile it. I can assure that ELKS runs properly in a 
machine with more than 640K, it just isn't aware of the additional memory.

It does appear that you have 768K. There are several possible explanations 
for this, among which are:
1. It actually is an AT-class board. If it's a desktop motherboard, check 
the expansion slots for two, rather than one connector per card slot.
2. It's an XT-286. I don't know just what they are, but I've seen  
references to them.
3. A decade or so ago there was a shortage of 64K memory chips. I heard
that some manufacturers changed their boards to accept the more-expensive
256K chips, which were more readily available. I don't know any details.

Some suggestions:
1. The next time you do a cold boot, look carefully at the memory size
message(s). If you see something about extended or expanded memory size,
in additional to the 640K "conventional" memory, then your computer is
almost certainly capable of using the additional memory (with the right
driver).
2. If you have the originals for your computer, check CONFIG.SYS and
AUTOEXEC.BAT for references to something line "himem", "emm", "qemm", or
"loadhigh". Any such lines would probably indicate that your computer can
use memory above the "conventional" 640K, and would indicate their proper
use.
3. ELKS seems to be quite good at identifying the processor. I haven't
tried it on an XT, but I've seen it correctly identify 286, 486, and
Pentium class processors. Check the first few lines printed on the screen
when ELKS boots to see if you actually have a 286. I don't remember if an
XT had an MMU chip, but if so it could probably map additional memory into
an unused area where an expansion-card ROM would otherwise be found (with
the right driver, of course). This area starts at segment C000 and ends
below segment E000 (or is it F000?). If you have a 286 or higher, an MMU,
and the right driver, you could probably map the additional memory above
the 8086's 1-Meg address limit.
4. Someone suggested that you use DEBUG to test memory in the Axxx and
Bxxx segments. That probably won't tell you anything usefull. That area is
reserved for memory on the video card, not on the motherboard. The DEBUG
commands stated were correct, however. Since XT harddrive controllers are
usually jumpered to start at segment C800, the data displayed by the 
DEBUG command:
	d c800:0000
will probably include some plain text indicating the hard drive controller
manufacturer, because almost all expansion card ROM's have some sort of
plain-text signature. Likewise, the "e" command allows you to not only
examine, but try to change memory. Note that, due to the way the circuitry
is usually designed, addresses with no corresponding RAM are likely to
display as "FF"; that is to say:
	Displays as:	Changable?	Is probably:
	FF		No		ROM or unused
	other than FF	No		ROM
	(anything)	Yes		RAM
This might help you identify areas where the right driver could map (or 
already has mapped) additional memory.

Re: 768k XT?

[Dan Olson]

> Alan Cox (and maybe others) actually answered your question about running
> ELKS on this machine last November when you were trying to run it on a
> 512K machine: ELKS is compiled to use exactly 640K; you *might* be able to
> use more if you re-compile it. I can assure that ELKS runs properly in a
> machine with more than 640K, it just isn't aware of the additional memory.

I understand that ELKS is compiled for 640k memory, my real question is
exactly what you mentioned, has anyone tried to recompile with more than
640k?  I get the impression that there is little chance of a) this working
and b) this being useful, though.

> It does appear that you have 768K. There are several possible explanations
> for this, among which are:
> 1. It actually is an AT-class board. If it's a desktop motherboard, check
> the expansion slots for two, rather than one connector per card slot.

It has 8 bit slots.

> 2. It's an XT-286. I don't know just what they are, but I've seen
> references to them.

I'm 99% sure I saw an 8088 in there.  I believe the XT-286 looks like an
XT to the outside world, using an XT keyboard and lacking space for a full
AT size expansion board.  Basicly IBM squeezed a 286 board in an XT case
:)

> 3. A decade or so ago there was a shortage of 64K memory chips. I heard
> that some manufacturers changed their boards to accept the more-expensive
> 256K chips, which were more readily available. I don't know any details.

This could very well be, and also, this board lacks room for two banks of
64k chips and instead has one bank of 256k chips.  It's very possible they
only intended to use 128k of that memory.

> Some suggestions:
> 1. The next time you do a cold boot, look carefully at the memory size
> message(s). If you see something about extended or expanded memory size,
> in additional to the 640K "conventional" memory, then your computer is
> almost certainly capable of using the additional memory (with the right
> driver).

Nope, it just lists the 640k.

> 2. If you have the originals for your computer, check CONFIG.SYS and
> AUTOEXEC.BAT for references to something line "himem", "emm", "qemm", or
> "loadhigh". Any such lines would probably indicate that your computer can
> use memory above the "conventional" 640K, and would indicate their proper
> use.

I picked this computer up second hand with no software.

> 3. ELKS seems to be quite good at identifying the processor. I haven't
> tried it on an XT, but I've seen it correctly identify 286, 486, and
> Pentium class processors. Check the first few lines printed on the screen
> when ELKS boots to see if you actually have a 286. I don't remember if an
> XT had an MMU chip, but if so it could probably map additional memory into
> an unused area where an expansion-card ROM would otherwise be found (with
> the right driver, of course). This area starts at segment C000 and ends
> below segment E000 (or is it F000?). If you have a 286 or higher, an MMU,
> and the right driver, you could probably map the additional memory above
> the 8086's 1-Meg address limit.

I *suspect* it's just a cheap 8088 with the minimal hardware, I would have
noted seeing a 286 while the cover was off.

> 4. Someone suggested that you use DEBUG to test memory in the Axxx and
> Bxxx segments. That probably won't tell you anything usefull. That area is
> reserved for memory on the video card, not on the motherboard. The DEBUG
> commands stated were correct, however. Since XT harddrive controllers are
> usually jumpered to start at segment C800, the data displayed by the
> DEBUG command:
> 	d c800:0000
> will probably include some plain text indicating the hard drive controller
> manufacturer, because almost all expansion card ROM's have some sort of
> plain-text signature. Likewise, the "e" command allows you to not only
> examine, but try to change memory. Note that, due to the way the circuitry
> is usually designed, addresses with no corresponding RAM are likely to
> display as "FF"; that is to say:
> 	Displays as:	Changable?	Is probably:
> 	FF		No		ROM or unused
> 	other than FF	No		ROM
> 	(anything)	Yes		RAM
> This might help you identify areas where the right driver could map (or
> already has mapped) additional memory.

This is my next step.  There is no hard drive controller, just a VGA board
and it's RAM/BIOS, and the system BIOS.  I'll report back with what I
find.

	Dan

Re: 768k XT?

[jb1]

On Tue, 10 Jun 2003, Dan Olson wrote:

> Hopefully someone knows, I have a Samsung XT clone that has 3 banks of

I ran across:
 	http://www.classiccmp.org
yesterday, but didn't look for your computer there because you didn't
specify the model. They discuss some of my "good old junk", so maybe
someone on that mailing list can help you.

Re: 768k XT?

[Dan Olson]

Thanks for the pointer, I'll take a look.  It's a SPC3000V made by
Samsung.

	Dan


On Sun, 15 Jun 2003 jb1@btstream.com wrote:

> On Tue, 10 Jun 2003, Dan Olson wrote:
>
> > Hopefully someone knows, I have a Samsung XT clone that has 3 banks of
>
> I ran across:
>  	http://www.classiccmp.org
> yesterday, but didn't look for your computer there because you didn't
> specify the model. They discuss some of my "good old junk", so maybe
> someone on that mailing list can help you.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-8086" in
> the body of a message to majordomo@vger.kernel.org
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>