xref: /openbsd-src/share/man/man4/vga.4 (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1.\" $OpenBSD: vga.4,v 1.3 2001/03/27 22:44:54 aaron Exp $
2.\" $NetBSD: vga.4,v 1.2.4.1 2000/08/09 07:48:40 drochner Exp $
3.\"
4.Dd March 20, 1999
5.Dt VGA 4
6.Os
7.Sh NAME
8.Nm vga
9.Nd VGA graphics driver for wscons
10.Sh SYNOPSIS
11.Cd "vga0 at isa?"
12.Cd "vga* at pci?"
13.Cd "wsdisplay* at vga? console ?"
14.Sh DESCRIPTION
15This driver handles VGA graphics hardware within the
16.Xr wscons 4
17console framework.
18It doesn't provide direct device driver entry points but makes its
19functions available via the internal
20.Xr wsdisplay 4
21interface.
22.Pp
23The
24.Nm
25driver supports multiple virtual screens on one physical display.
26The screens allocated on one display can be of different
27.Dq types ,
28where a type refers to various display properties.
29The type is determined at the time the virtual screen is created and can't
30be changed later.
31Screens are either created at kernel startup (then the default type is used)
32or later with help of the
33.Xr wsconscfg 8
34utility.
35.Pp
36Currently, the following screen types are supported:
37.Bl -hang
38.It 80x25
39This is the standard VGA text mode with 80 columns and 25 rows.
4016 different colors can be displayed at the same time.
41Characters are 8 x 16 pixels large, and a font consists of 256 characters.
42A built-in font of this size is always present on a VGA card.
43It's also possible to use a downloaded font instead.
44.It 80x25bf
45A modified version of the previous.
46It only allows 8 colors to be displayed.
47In exchange, it can access two fonts at the same time, so that 512
48different characters can be displayed.
49.It 80x40
50A text mode with 80 colums and 40 rows.
51Similar to the standard mode, 16 colors and 256 characters are available.
52Characters are 8 x 10 pixels large.
53For this mode to be useful, a font of that character size must be downloaded.
54.It 80x40bf
55A modified version of the previous.
56It only allows 8 colors to be displayed.
57In exchange, it can access two fonts at the same time, so that 512
58different characters can be displayed.
59.It 80x50
60A text mode with 80 colums and 50 rows.
61Similar to the standard mode, 16 colors and 256 characters are available.
62Characters are 8 x 8 pixels large.
63For this mode to be useful, a font of that character size must be downloaded.
64.It 80x50bf
65A modified version of the previous.
66It only allows 8 colors to be displayed.
67In exchange, it can access two fonts at the same time, so that 512
68different characters can be displayed.
69.It 80x24
70A variant of the
71.Dq 80x25
72screen type which displays 24 lines only.
73It uses the standard 8x16 VGA font.
74This mode might be useful for applications which depend on closer
75DEC VT100 compatibility.
76.It 80x24bf
77A modified version of the previous.
78It only allows 8 colors to be displayed.
79In exchange, it can access two fonts at the same time, so that 512
80different characters can be displayed.
81.El
82.Pp
83The
84.Nm
85driver can display fonts of the original IBM type and ISO-8859-1 encoded fonts.
86As an experimental feature, the
87.Dq higher half
88fonts of the former OpenBSD/i386
89.Xr pcvt 4
90driver distribution can be used too if
91.Em option WSCONS_SUPPORT_PCVTFONTS
92was set at kernel compile time.
93This is only useful with the
94.Dq *bf
95screen types; a font containing the ASCII
96range of characters must be available too on this screen.
97.Sh SEE ALSO
98.Xr isa 4 ,
99.Xr pcdisplay 4 ,
100.Xr pci 4 ,
101.Xr wscons 4 ,
102.Xr wsconscfg 8 ,
103.Xr wsfontload 8
104.Sh BUGS
105Only a subset of the possible text modes is supported.
106.Pp
107VGA cards are supposed to emulate an MDA if a monochrome display is connected.
108In this case, the device will naturally not support colors at all, but
109offer the capability to display underlined characters instead.
110The
111.Dq 80x25bf ,
112.Dq 80x40bf ,
113.Dq 80x50bf ,
114and
115.Dq 80x24bf
116screen types will not be available.
117This mode of operation is not tested.
118