Set shared video memory in xorg.conf

["David R. Litwin" <presently42@gmail.com>]

Hello, list.

I recently acquired a 512 MB of ram to bring my laptop to a grand total of 1024. With this amount, I would like to increase the memory of my shared video card form 128 to 256, the max, in order to speed up graphics et cetera.

Since I have edited the xorg.conf file, I ran the suggested dpkg-reconfigure -phigh xserver-xorg. Then, running dpkg-reconfigure xserver-xorg, I input the amount of memory I wanted shared in kB. Well, it didn't work; 
xorg.conf was not updated.

So, what do I have to put in to the file to get 256 mB of ram for my shared video card?

Thanks much.

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