Using Multiple Monitors with SPM

These notes include information that has been kindly provided by Ron Labbe and Werner Bloos.

Win98 onwards has supported multiple monitors, up to nine video adapters for Win98/ME and up to ten for Win2000/XP.
(Some video card manufacturers support multiple displays on Windows 95 & NT 4.0).
Some video adapters can have 2,4 or 8 outputs so potentially very large 'wall' configurations are possible.
The operating system sets up a 'virtual display' in video-memory and maps parts of it to individual monitors.
This allows you to drag windows to any monitor, except the primary monitor which is always at top-left in the 'virtual display'.
You can mix AGP (one card only) and PCI video cards but ISA is not supported.
Adapters are also available to drive a monitor from a USB port.
One of the cards will be used as the BIOS primary video card and this is the card which is active during system startup.
It displays BIOS messages and the Windows boot progress, and it is also the card which will be used for fullscreen DOS applications.
The BIOS primary card is either the AGP card or the first PCI video card (the one in the lowest-numbered slot, nearest to the AGP slot).
To choose whether AGP or PCI should be primary, enter the BIOS setup during booting and look for a setting called 'Initialize First', 'Init Display First' or similar.
On Windows 2000/XP, you can set any card as primary in Display Properties, but DOS applications will still use the BIOS primary display.
You should check that a proposed PCI card will work correctly as a secondary, especially if it is an ATI.
Old PCI video cards (S3 Trio, ATI Rage, etc) need to be primary in BIOS in order to work with Windows 2000/XP.
Because only a single card can be primary in BIOS, this means that you're limited to a single card of this type per system.
With multiple monitors, you may have to disable secondary monitors before starting OpenGL applications on the primary, it depends on the driver.
Once the OpenGL application has started, you may enable the secondary monitors.
Because Windows 2000/XP use different display drivers than Windows 98/Me, some configurations that work with 98/Me might not work with Windows 2000/XP.
Again, because new chipsets, updated drivers, and combinations of display adapters are a continuous issue for multiple-monitor support when separate video cards are used, there can be difficulties setting-up a multimonitor system, especially for stereo.

The following links provide useful information :-

In the standard Windows 98 multimonitor support, the desktop area is spread across both displays.
The refresh rate, color depth, and resolution may be independently set for each display

. In addition to the standard Win98 multimonitor support, Win2000/XP have 'Dualview' (Extended desktop) mode that treats two displays as separate devices.
Maximizing the window in the first display does not maximise the window in the second display.
Windows XP is pre-configured to use Dualview mode with multiple monitors (Win2000 is not).
Graphic-card vendor's support other modes such as NVidia's horizontal/vertical Span ('Big desktop') and Clone.
NVidia nView supports Dualview(Extended Desktop), clone and span modes.
Dualview is a 'native' windows mode that can be used with separate graphics cards, 'Span' and 'Clone' are only supported on certain multi-output graphics cards.
For separate cards, NVidia recommend that the same GPU be used and the same driver MUST be used.
Under Win2000/XP, NVidia also strongly recommend that Dualview is used with multiple monitors.

Dualview Mode

The above dialog-boxes show a dual-output FX5200 graphics-card setup for Dualview.
From version 2.32 onwards, SPM supports Dualview using windowed, fullscreen or dual fullscreen modes.

You may choose the left (Alt+Enter) or right (Ctrl+Alt+Enter) device as SMM's 'primary'.

The primary monitor on the left can extend its desktop onto the right-hand monitor.
The taskbar only appears on the primary monitor and each monitor has its own background.
SPM has been opened in a window on the primary monitor.

Here SPM's window has been maximized.

... and here fullscreen mode has been selected.

By selecting the menu-option 'Dual Fullscreen' or pressing 'Alt' + Enter' keys, the left/right views are displayed fullscreen on separate monitors (or projectors).

Span Mode

In the above screenshot, each monitor is set to 1024x768 resolution and the reported resolution of the 'single' display is 2048x768.

Horizontal Span Mode is like one double width monitor with the desktop and taskbar stretched over both of them.
Here, SPM has been opened in a window

... and its window has been maximized.

... and here fullscreen mode has been selected.

... and here dual fullscreen (which is obviously unsuitable for our purposes).

Clone Mode

In clone mode, the two monitors display exactly the same image. Here, SPM is opened in a window.

... the window is maximized

... and here fullscreen is chosen.

... and here dual fullscreen is chosen.