odd memory issue??

[#1]

I have a toshiba satellite 1130. A while ago it was dropped and the MOBO decided to give up the ghost, after days of searching I eventually found one for the Jap version of the 1130, the dynabook E series. It fit fine but some keys would not work, but English Xp loaded fine, and everything else worked OK, except BIOS in JApanese!!!! A few days ago after some searching, I located an english MOBO, that had a broke power connector. I replaced this, and put this MOBO in the system. Powered Up OK, and I updated the BIOS to the latest version, but I noticed the memory was displayed as 640kb Base memory, 496Mb Extended. I assumed this was for the video memory. I reloaded XP Pro, and the memory is still shown as 496Mb instead of 512, but on further searching, the video RAM is shown as 64Mb, it is an Intel 82852/82855 Gm/GME chipset. I cannot for the life of me figure this out. The system works perfectly, I was just confused as to this, and where this 16Mb of RAM has gone. Its probably something simple and I will feel a complete numpty when its explained, as I should know better, but would welcome advice.

[#2]

the 640kb Base memory, 496Mb Extended is the way memory was shown in good old DOS as 640Kb was the max you could have as base memory anything else had to be extended. All old pc used to report memory in this way.
I would have thought the laptop which is old would have been more advanced than this but its all correct just how its reported

[#3]

Somewhere in my archives I have a 1MB EXPANDED memory board for an IBM compatible PC.
Now, who can explain the difference between Expanded and Extended memory?
PS Samuria, sorry but "anything else had to be extended" isn't correct as there is also expanded memory. Not to mention the "reserved" memory between 640KB and 1MB.....
See http://en.wikipedia.org/wiki/Expanded_memory if you are interested.

[#4]

For expanded memory you need a add on board on the standard MB everything was extended. Then were the days when to format a HD you had to go into debug and type go g800 for a bios routine to low level format the drive.
People dont know what they have missed as once you had low level formated you had to then format again and you had to set up the interleave for the drive to get the best from it. Bring back Quemm and Desqview were you could load 10 programs before windows had started

[#5]

I'm sitting at my desk looking at a noticeboard with an old 286 motherboard pinned to it.
It had 512KB memory which I remember upgrading to 640 by buying the chips and putting them in myself. 6 chips - 4 each of 32K and 2 smaller ones for parity.
It's also got a pair of revised BIOS chips that I think I had blown to support larger capacity hard disk types up to 80MB I think.
The motherboard says NCR '86 (that's 1986).
IIRC it came from a server running Pick for a telesales team system. When it was retired in the early 90's I "upgraded" it to run DOS. 

[#6]

Thanks for the trip down memory lane chaps 
Anyhow, anybody any idea where this memory has gone, or is it just a case of how its displayed in this older laptop?

[#7]

As far as I understand those onboard intel boards the memory is shared between the computer itself and the video card, depending on how much each side needs. I assume at bootup it only needs 16MB (or that that is the minimum that it can be allocated) and as such this is why the memory isn't shown, however if you run something a bit more graphics intensive in windows and check the system properties I suspect you'll find that the amount of available RAM has dropped again.
I may be wrong, but it's how I always understood those cards to work.
Hope that helps,

[#8]

That's not my understanding.
Somewhere in the BIOS you can normally set how much main memory is to be used for graphics but on some systems it is a fixed value which cannot be changed. Once set (or preset by the system), this is all it is able to use and does not 'adjust' as it goes on which is what I think you are saying.
Note to OP: don't confuse the video memory allocation from the AGP aperature size value shown in the BIOS as they are toally different things. The AGP aperature can be different to the actual ram used by the graphics chip.
It does look like the mobo uses a fixed 16MB of main memory for graphics hence why windows reports 496MB.

[#9]

Thanks Chaps, that was the premise I was going on. There appears to be no setting in the BIOS to set VGA memory.  Thing that confused me was, when I look at the graphics card propertys in the advanced tab, of the diplay propertys, its reporting the memory is 64Mb.  System works fine, just wondered about the apparant difference.

[#10]

http://www.intel.com/support/graphics/intel852gm/sb/CS-009069.htm
Seems like I was right.

[#11]

Thanks for the link matt.  I will take a look later at this.
Cheers

[#12]

Just had a look, and you were correct. 64Mb is the max to be used, and 15Mb the minimum.
Thanks for the advice 

[#13]

I sit corrected 
Although it is somewhat unusual in my experience.