Hi. I have two S3 Virge DX on a PC system, as well as a mono card (a total of three monitors: two color (17" and 14"), and other mono. The resources shown by W98 are: Virge #1 Memory intervals: 000A0000 - 000AFFFF 000B0000 - 00BFFFFF E0000000 - E3FFFFFF 00C00000 - 00C7FFFF 06000000 - 0600FFFF E0000000 - E3FFFFFF I/O intervals: 03B0-03BB 03C0-03DF IRQ11 Virge #2 Memory intervals: 06010000 - 0601FFFF 08000000 - 0BFFFFFF IRQ11 W98 ignores the mono card, except for LPT1; as long as I use it only for text there is no problem, in spite of Virge #1 showing it occupies 0B000-0B7FF. Also, although it shows IRQ11 is used by both, in fact #INTA on both cards is unused unless connecting something to its expansion connector. It is surprising that Virge #2 is correctly programmed, even not showing i/o ports. Now, a simple experiment: open a DOS window on Virge #2 (so on second monitor, so its pixels come from #2 card). Press Alt+Enter to maximize it: it maximizes on first monitor!!! (so its pixels now come from Vige #1). This confirms use of range 0B800-0BFFF. W98 supports fairly well several video cards. For example, a window partly in both monitors seems to be maximized on the monitor in which it has more pixels. However, it seems that only first monitor has screen protector, although energy savings turn of both monitors. RealAudio messes a bit with two monitors (I posted something about this some time ago, with no feedback). ************************************ Javier Vizcaino. Ability Electronics. [log in to unmask] http://www.automodelismo.com http://ability53.hypermart.net Starting point: (-1)^(-1) = -1 Applying logarithms: (-1)*ln(-1) = ln(-1) Since ln(-1) <> 0, dividing: -1 = 1 (ln(-1) is complex, but exists) ----- Mensaje original ----- De: David Gillett <[log in to unmask]> Para: <[log in to unmask]> Enviado: martes 30 de marzo de 1999 0:10 Asunto: Re: [PCBUILD] Multiple video cards > On 28 Mar 99, at 15:36, Max Timchenko wrote: > > > How exactly can 2 cards live in one system? they compete for same > > address space ($a000:0 and up), won't it cause conflicts? > > All VGA cards have to provide modes where the video RAM can be mapped > into the A000 segment (64K at a time) in order to be accessible from > DOS programs. That is true. > > However, constantly mapping and re-mapping this address space is > ugly, time-sonsuming, and pretty boring. Most modern video cards > *also* map their entire RAM to space at a high (non-swappable) virtual > address, where protected-mode software can read and write it directly; > the drivers for the card know where this mapping is, or how to find it. > > So there's only a conflict at A000 if both cards are trying to > provide real-mode (DOS-compatible) access to video RAM. As long as at > least one of them has this mapping suppressed, there's no conflict. > [Actually, under NT and 9x, this mapping is generally done by the OS, > and used to connect to a "DOS window" on the screen, instead of > connecting directly to the video RAM. So it's "extremely normal" for a > video card under Win32 not to map to A000 at all. > > [There is a secondary issue that two VGA/SVGA cards would normally > want to use the same range of I/O port numbers and IRQ (if any); > solving that part of the problem seems like a natural extension of PnP, > which would I think be why this feature is only supported by fairly > recent cards.] > > > David G Do you want to signoff PCBUILD or just change to Digest mode - visit our web site: http://nospin.com/pc/pcbuild.html