Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sun, 31 Mar 1996 18:44:36 -0500 (EST) | From | Antoine Reid <> | Subject | Two (S)Vga at the same time (PCI System) |
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On Sun, 31 Mar 1996, Tom May wrote:
> Date: Sun, 31 Mar 1996 15:10:01 -0800 > From: Tom May <ftom@netcom.com> > To: dpates@cavern.nmsu.edu > Cc: fluke@mlink.net, linux-kernel@vger.rutgers.edu > Subject: Re: Dual Monitor > > Derrik Pates <dpates@cavern.nmsu.edu> writes: > > >If you have a PCI-based system, 2 (S)VGA cards is not a problem. > > It has at least the following problems: > > 1. You've got to initialize all the VGAs you want to use. On system > startup only one VGA gets initialized, and the code that does the job > is in the VGA BIOS. All other VGAs are disabled. Initializing a VGA > is chip-specific and non-trivial.
What if we talk about a (s)vga [either isa, vesa or pci] and a mono [isa..] hercules/mda card? Do you think the mono card is init'es at bootup? mine is usable in mess-dos so I guess it is ... (?)
> 2. If you are using the VGA I/O registers (0x3C4, etc.) and memory > ranges (0xA0000, etc.), you will only be able to access one chip > at a time.
This could be resolved, I guess ... well at least it would be doable, but if we're dealing with mono card, it is using 0xB800 (if memory's good...) and registers won't be much used either ...
> 3. Assuming point 2 is not a problem, you still have to manage to get > the VGA I/O and memory accesses forwarded to the PCI bus that the VGA > you are currently using is located on. You can't assume all the VGAs > are on the same bus.
not relevant to mono ?
> I've had to deal with these problems, so I know what I'm talking > about.
would you be interested to be part of the coding team for that? would you even coordinate the work?
thanx for reading Antoine
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