Version 1.0 of the VESA Super VGA Standard (#VS891001) is supported.“Super VGA” (SVGA) does not describe a standard display adapter. Instead, it refers to any VGA-compatible video adapter that also provides higher resolution modes. SVGA adapters made by different manufacturers may support different extended resolution modes.
Summary: Microsoft C graphics libraries support the VESA interface.
To allow your programs to take advantage of different SVGA adapters, the Microsoft C graphics libraries support the interface defined by the Video Electronics Standards Association (VESA). VESA has defined a standard interface for accessing the extended features of different SVGA adapters, and this interface is widely supported by video hardware manufacturers. This allows your graphics program to run with virtually any adapter that is VESA-compliant.
The _setvideomode function supports eight extended resolution modes, some or all of which are available on VESA-compliant SVGA adapters: _ORES256COLOR, _VRES256COLOR, _SRES16COLOR, _SRES256COLOR, _XRES16COLOR, _XRES256COLOR, _ZRES16COLOR and _ZRES256COLOR. (These modes represent BIOS numbers 0x0100 through 0x0107, respectively, in the VESA standard.) Consult the owner's manual to see which modes your adapter supports.
Note that having an SVGA adapter is not sufficient for using one of these extended modes. You must also have a display monitor that supports the higher resolution. Only the first two of the extended modes can be displayed on a standard VGA analog monitor. The other extended modes require special monitors.
Warning:
Do not attempt to use any of the _SRES, _XRES, or _ZRES modes unless your display monitor supports them. Otherwise, you risk damaging your display monitor. If you use one of the extended modes in a program intended for use by others, inform the program's users of its monitor requirements. This is especially important with software intended for resale or for wide distribution. Microsoft assumes no responsibility for damage to video monitors resulting from use of this software. Consult your owner's manual for details.
You can also use _setvideomode to select a nonstandard graphics mode that is specific to a particular manufacturer's adapter, if the adapter is VESA-compliant. Consult your adapter's owner's manual for the BIOS number of a given mode, and pass that number as the argument to _setvideomode. The BIOS number must be between 0x15 and 0x7F. Typically, these additional modes differ from the eight modes listed above only in resolution, not in number of colors. The _setvideomode function may not support all of an adapter's extended modes.
Some SVGA adapters provide the VESA interface in ROM. Other adapters require that you install a TSR (Terminate-and-Stay Resident) program. Microsoft C/C++ includes TSRs for several adapters (see the file PACKING.LST for a list of TSRs supplied). If the TSR for your adapter is not included, contact your dealer or video adapter manufacturer.
These TSRs are executable programs with names of the form xxxVESA.COM or xxxVESA.EXE. You install the TSR by running the program. You must install the TSR before you run a graphics program that uses one of the VESA extended modes. If you don't install the TSR, your SVGA adapter behaves like a standard VGA adapter.
NO WARRANTY:
These drivers are provided on an as-is, unsupported basis, without any claim as to their correctness or suitability. Neither Microsoft nor the TSR vendor makes any representations or warranties regarding the capabilities or performance of the TSR software. Should you want to distribute any of the supplied TSRs with a software program developed using Microsoft C/C++, it is your responsibility to obtain permission from VESA and/or the TSR vendor.
The graphics libraries may not work with all hardware and TSR combinations. Furthermore, VESA support has the following limitations:
Version 1.0 of the VESA Super VGA Standard (#VS891001) is supported.
Only color graphics modes are supported.
Output functions must be supported by the BIOS.
Only single window systems, as defined in section 5.2.1 of the VESA Super VGA Standard, are supported. The single window (window A) must be both readable and writeable.
The only window size (WinSize) supported is 64K. Some adapters have an option of using either a 64K single-window, or a 32K double-window mode. Your adapter must be configured for 64K mode.
The window granularity (WinGranularity) must be a power of 2.
The memory model must be either 4-plane planar (16-color) or packed pixel (256-color).
Consult the VESA Super VGA Standard and your adapter's owner's manual for details. For a copy of the Super VGA Standard, write to the Video Electronics Standards Association (VESA) in San Jose, California.