NAME
vga —
VGA graphics driver for
wscons
SYNOPSIS
vga0 at isa?
vga* at pci?
wsdisplay* at vga?
agp* at vga?
DESCRIPTION
This driver handles VGA graphics hardware within the wscons(4) console framework. It doesn't provide direct device driver entry points but makes its functions available via the internal wsdisplay(4) interface.
The vga driver supports multiple virtual
screens on one physical display. The screens allocated on one display can be
of different “types”, where a type refers to various display
properties. The type is determined at the time the virtual screen is created
and can't be changed later. Screens are either created at kernel startup
(then the default type is used) or later with help of the
wsconscfg(8) utility.
Currently, the following screen types are supported:
- 80x25
- This is the standard VGA text mode with 80 columns and 25 rows. 16 different colors can be displayed at the same time. Characters are 8 x 16 pixels large, and a font consists of 256 characters. A built-in font of this size is always present on a VGA card. It's also possible to use a downloaded font instead.
- 80x25bf
- A modified version of the previous. It only allows 8 colors to be displayed. In exchange, it can access two fonts at the same time, so that 512 different characters can be displayed.
- 80x40
- A text mode with 80 columns and 40 rows. Similar to the standard mode, 16 colors and 256 characters are available. Characters are 8 x 10 pixels large. For this mode to be useful, a font of that character size must be downloaded.
- 80x40bf
- A modified version of the previous. It only allows 8 colors to be displayed. In exchange, it can access two fonts at the same time, so that 512 different characters can be displayed.
- 80x50
- A text mode with 80 columns and 50 rows. Similar to the standard mode, 16 colors and 256 characters are available. Characters are 8 x 8 pixels large. For this mode to be useful, a font of that character size must be downloaded.
- 80x50bf
- A modified version of the previous. It only allows 8 colors to be displayed. In exchange, it can access two fonts at the same time, so that 512 different characters can be displayed.
- 80x24
- A variant of the “80x25” screen type which displays 24 lines only. It uses the standard 8x16 VGA font. This mode might be useful for applications which depend on closer DEC VT100 compatibility.
- 80x24bf
- A modified version of the previous. It only allows 8 colors to be displayed. In exchange, it can access two fonts at the same time, so that 512 different characters can be displayed.
The vga driver can display fonts of the
original IBM type and ISO-8859-1 encoded fonts. As an experimental feature,
the “higher half” fonts of the former
OpenBSD/i386 pcvt driver distribution can be used
too if option WSCONS_SUPPORT_PCVTFONTS was set at
kernel compile time. This is only useful with the “*bf” screen
types; a font containing the ASCII range of characters must be available too
on this screen.
SEE ALSO
agp(4), intro(4), isa(4), pcdisplay(4), pci(4), wscons(4), wsdisplay(4), wsconscfg(8), wsfontload(8)
BUGS
Only a subset of the possible text modes is supported.
VGA cards are supposed to emulate an MDA if a monochrome display is connected. In this case, the device will naturally not support colors at all, but offer the capability to display underlined characters instead. The “80x25bf”, “80x40bf”, “80x50bf”, and “80x24bf” screen types will not be available. This mode of operation is not tested.