whb@castle.ed.ac.uk (H Bruce) (05/29/91)
We have some Elonex 386SX AT clones that have an integrated IO card (ie disk, serial, parallel and video I/O). The VGA chip is a Chips & Tech 82C451 with 256K of RAM. It only seems to support a 800x600x16 SVGA video mode and ignores attempts to switch it into the 640x480x256 mode. However there is space on the card for another 256K of RAM - if this is installed with the 640x480x256 mode work ? The suppliers say they won't do the upgrade and if we do it'll void the warranty !! Futhermore the "Programmer's Guide to VGA Cards" does not explicity say that the card will or will not support the 256 colour SVGA mode. Any help greatly appreciated, Henry Bruce
dj@ctron.com (DJ Delorie) (05/30/91)
In article <10654@castle.ed.ac.uk>, whb@castle.ed.ac.uk (H Bruce) writes: > The VGA chip is a Chips & Tech 82C451 with 256K of RAM. > It only seems to support a 800x600x16 SVGA video mode and ignores attempts to > switch it into the 640x480x256 mode. > However there is space on the card for another 256K of RAM - if this is > installed with the 640x480x256 mode work ? > The suppliers say they won't do the upgrade and if we do it'll void > the warranty !! Futhermore the "Programmer's Guide to VGA Cards" does > not explicity say that the card will or will not support the 256 > colour SVGA mode. I used to work with C&T and this chip at a previous job, and the info I got back then is that the '451 can do 800x600x16 (and maybe 640x400x256 - I don't recall), but the '452 is required to do more than that. DJ dj@ctron.com