xref: /netbsd-src/share/man/man4/vga.4 (revision 997634fe1470bb1edef8e5d52fc996f52c9c958f)
1.\" $NetBSD: vga.4,v 1.15 2009/03/09 19:24:28 joerg Exp $
2.\"
3.\" Copyright (c) 1999, 2000
4.\" 	Matthias Drochner.  All rights reserved.
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright
10.\"    notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\"    notice, this list of conditions and the following disclaimer in the
13.\"    documentation and/or other materials provided with the distribution.
14.\"
15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25.\" SUCH DAMAGE.
26.\"
27.Dd May 4, 2003
28.Dt VGA 4
29.Os
30.Sh NAME
31.Nm vga
32.Nd VGA graphics driver for wscons
33.Sh SYNOPSIS
34.Cd options VGA_CONSOLE_SCREENTYPE="??x??"
35.Cd options VGA_CONSOLE_ATI_BROKEN_FONTSEL
36.Pp
37.Cd "vga0 at isa?"
38.Cd "vga* at pci?"
39.Cd "wsdisplay* at vga? console ?"
40.Sh DESCRIPTION
41This driver handles
42.Tn VGA
43graphics hardware within the
44.Xr wscons 4
45console framework.
46It doesn't provide direct device
47driver entry points but makes its functions available via
48the internal
49.Xr wsdisplay 4
50interface.
51.Pp
52The
53.Nm
54driver supports text-mode hardware acceleration on the
55.Tn VGA
56hardware.
57Currently, the driver runs the display with a 720\(mu400 pixel resolution.
58The
59.Tn VGA
60text-mode accelerator divides the display into fixed-size
61character cells.
62The size of the character cells specifies the number of characters available
63on the screen and the resolution of the font.
64The wsdisplay screen
65.Dq types
66supported by the
67.Nm
68driver are described by the number of character cells available
69on the screen.
70See below for a complete list of supported screen modes in the
71.Nm
72driver.
73.Pp
74Each screen mode requires a suitable font to be loaded into
75the kernel by the
76.Xr wsfontload 8
77utility, before the screen can be used.
78The size of the font
79and the screen mode must match for use on the 720\(mu400 display.
80For example, a screen mode with 80 columns and 40 rows requires
81a font where each character is 8 pixels wide and 10 pixels high.
82The
83.Nm
84driver can display fonts of the original
85.Tn IBM
86type and ISO-8859-1 encoded fonts.
87A builtin font of 256 characters and 8\(mu16 pixels is always
88present on the
89.Tn VGA
90hardware.
91.Pp
92The colour
93.Tn VGA
94hardware supports the display of 16 different colours at the same
95time.
96It is possible with
97.Tn VGA
98colour systems to use fonts with 512 characters at any one time.
99This is due to the fact that with VGA adapters one can specify an
100alternate font to be used instead of bright letters
101(used for highlighting on the screen).
102As an experimental feature, the
103.Dq higher half
104fonts of the former
105.Nx Ns /i386
106.Nm pcvt
107driver distribution can be used too if the kernel option
108.Dq WSCONS_SUPPORT_PCVTFONTS
109was set at compile time.
110This is only useful with the
111.Dq *bf
112screen types; a font containing the
113.Tn ASCII
114range of characters must be available too on this screen.
115.Pp
116Currently, the following screen types are supported:
117.Bl -hang
118.It 80x25
119This is the standard
120.Tn VGA
121text mode with 80 columns and 25 rows.
122Sixteen different colors can be displayed at the same time.
123Characters are 8\(mu16 pixels, and a font consists of 256 characters.
124.It 80x25bf
125is a modified version of the previous.
126It only allows 8 colors to be displayed.
127In exchange, it can access two fonts at the same time, so that
128512 different characters can be displayed.
129.It 80x40
130A text mode with 80 columns and 40 rows.
131Similar to the standard mode, 16 colors and 256 characters are
132available.
133Characters are 8\(mu10 pixels.
134For this mode to be useful, a font of that character size must
135be downloaded.
136.It 80x40bf
137is analogously to
138.Dq 80x25bf
139a version with 512 displayable characters but 8 colors only.
140.It 80x50
141A text mode with 80 columns and 50 rows.
142Similar to the standard mode, 16 colors and 256 characters are
143available.
144Characters are 8\(mu8 pixels.
145For this mode to be useful, a font of that character size must
146be downloaded.
147.It 80x50bf
148is analogously to
149.Dq 80x25bf
150a version with 512 displayable characters but 8 colors only.
151.It 80x24
152is a variant of the
153.Dq 80x25
154screen type which displays 24 lines only.
155It uses the standard 8x16 VGA font.
156This mode might be useful for applications which depend on closer
157.Tn DEC VT100
158compatibility.
159.It 80x24bf
160Analogously, like
161.Dq 80x24
162but with 512 character slots and 8 colors.
163.El
164.Pp
165If you have an Ati videocard and you are experiencing problems with
166fonts other than 80x25, you can try to set
167.Cd options VGA_CONSOLE_ATI_BROKEN_FONTSEL
168in you kernel configuration and see if it helps.
169.Pp
170The
171.Nm
172driver supports multiple virtual screens on one physical
173display.
174The screens allocated on one display can be of different
175.Dq types .
176The type is determined at the time the virtual screen is created
177and can't be changed later.
178Screens are either created at kernel startup
179(then the default type is used) or later with help of the
180.Xr wsconscfg 8
181utility.
182.Sh SEE ALSO
183.Xr isa 4 ,
184.Xr pcdisplay 4 ,
185.Xr pci 4 ,
186.Xr wscons 4 ,
187.Xr wsconscfg 8 ,
188.Xr wsfontload 8
189.Sh BUGS
190Only a subset of the possible text modes is supported.
191.Pp
192.Tn VGA
193cards are supposed to emulate an
194.Tn MDA
195if a monochrome display is connected.
196In this case, the device will naturally not support colors at
197all, but offer the capability to display underlined characters
198instead.
199The
200.Dq 80x25bf ,
201.Dq 80x40bf ,
202.Dq 80x50bf
203and
204.Dq 80x24bf
205screen types will not be available.
206This mode of operation has not been tested.
207