Subject: Re: is ANYONE running multiple vga cards right now.
To: Todd Whitesel <toddpw@best.com>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: current-users
Date: 08/27/1999 17:34:09
On Fri, 27 Aug 1999 17:26:03 -0700 (PDT) 
 Todd Whitesel <toddpw@best.com> wrote:

 > > Also, isn't VGA's video RAM always at 0xa0000? I even see that address
 > > hardcoded in sys/dev/ic/vga.c. Makes it sound like it might be pretty
 > > tough getting multiple cards running in text mode :(
 > 
 > You're right -- for ISA video cards.
 > 
 > But I'm talking about PCI video cards, which have to use address ranges
 > assigned to them by the BIOS.
 > 
 > There's a reason the i386 GENERIC config file does it like this:
 > 
 > 	vga0 at isa?
 > 	vga* at pci? device ? function ?
 > 
 > You get one ISA card, but as many PCI/AGP cards as you have slots for.

Not quite.

If the card reports itself as "PCI VGA", then, per the spec, it maps
itself into legacy ISA VGA space, too.

Obviously, only one board can do that.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>