[Lancaster] X config query

[Andy Baxter]

I've been setting up a machine for use in the resource centre under single 
step, and I've been having a problem with the X configuration. The trouble 
is, it only does 640x480 at 15 or 16 bpp when I want it to do 800x600. I 
don't think it's because of the graphics card's memory, because it does 
1024x768 at 8bpp perfectly happily, and usually if it will do that, it can do 
the next lower res mode at full colour.

I've done the maths for the raw memory requirements of the different modes 
(i.e. excluding any memory the card needs for its own operations), and it 
works out like this:

mode		mem at 8bpp	mem at 16bpp
640x480	300k		600k
800x600	469k		937k
1024x768	768k		1536k

>From this, it could just be that the card's memory is somewhere between 768 
and 937k, but this seems odd as I thought most older cards had at least 1M of 
memory (the 486SX I bought ten years ago did, anyhow). Is there any way in 
software to query the card to find out how much memory it actually has? (It's 
a cirrus)

Another possibility, is if there is only 768k of memory on the card, it 
should be possible to run it at 724x543 at 16bpp, but I don't know if Linux 
supports non-standard video modes and how you would set them up in the config 
file.

Andy.