Date: Sat, 24 Oct 1998 08:43:10 +0930 From: Greg Lehey <grog@lemis.com> To: Nick Hibma <nick.hibma@jrc.it>, FreeBSD hackers mailing list <hackers@FreeBSD.ORG> Subject: Re: multi-user: multiple consoles in FreeBSD Message-ID: <19981024084310.O28824@freebie.lemis.com> In-Reply-To: <Pine.GSO.3.95q.981023093009.18824e-100000@elect8>; from Nick Hibma on Fri, Oct 23, 1998 at 09:32:27AM %2B0200 References: <199810230127.SAA02423@dingo.cdrom.com> <Pine.GSO.3.95q.981023093009.18824e-100000@elect8>
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On Friday, 23 October 1998 at 9:32:27 +0200, Nick Hibma wrote: > On Thu, 22 Oct 1998, Mike Smith wrote: > >>>> Jason's gripe was that you con't have more than one video card because >>>> the second wants its VGA-compatibility registers mapped in the same >>>> place as the first. >>> >>> Right, but there are ways to disable it. >> >> Yes, although they're not in our hands. >> >>>> Unless there's something really odd going on, it's relatively >>>> trivial to simply map the I/O ranges for display cards other than >>>> the first somewhere else; you just need the smarts in your system to >>>> do this. >>>> >>>> Video chipsets not supporting this would be in violation of the PCI >>>> spec. I wouldn't expect this to be too common. >>> >>> Hmmm. How would you go about doing it? It would have to be in the >>> BIOS setup, and I can't see anything there that allows it. I suppose >>> you could start up with one video BIOS disabled, and then enable it >>> programmatically during the boot. >> >> There are several components which need to play "nice" for it to work. >> >> The system BIOS has to do the "right thing" when it's setting the >> PCI interfaces on the cards up; it needs to deal with the case where >> it's got more than one device that says it's a VGA adapter, and only >> map one of them in. If it's stupid it may crash or map them both >> (which would probably hang the bus). >> >> Then the BIOS on the card that doesn't have the compatibility mappings >> has to realise the fact. If it doesn't, it will try to talk to the >> registers as though they were for it, which would be bad. It might be >> less bad if all the cards were identical. >> >> Since Jason claims to have tested this and failed, while I know that you >> have at least one well-behaved card, it seems to be a bit of a mixed >> bag. I wonder if the current crop of ATI cards still work? I've got a >> pair of Rage 3DII's here I could try it with. > > Greg, if you could give me/the list (probably more than me alone who > might have a spare monitor somewhere to play with) a hint on which cards > you have been able to do this with, I could appreciate a hint. The same > brand is needed for all the cards or does that not matter? The boards don't have to be the same; here's the dmesg output I posted yesterday: vga0: <Matrox MGA 2064W graphics accelerator> rev 0x01 int a irq 10 on pci0.10.0 vga1: <ATI Mach64-CT graphics accelerator> rev 0x09 on pci0.11.0 My "list" is way out of date, up to several years. I basically went by what the XI Graphics server could support, and that kept changing with the release (one of the reasons I won't upgrade to a newer version; I'll keep my current version 1.3 (!) until XFree86 4.0 is available, and then I'll switch to that. But XI Graphics do specify which boards their multi-head server supports; check out http://www.xig.com/board/mx/bdindex.html. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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