2 .\" Copyright (c) 1994 Joerg Wunsch
4 .\" All rights reserved.
6 .\" This program is free software.
8 .\" Redistribution and use in source and binary forms, with or without
9 .\" modification, are permitted provided that the following conditions
11 .\" 1. Redistributions of source code must retain the above copyright
12 .\" notice, this list of conditions and the following disclaimer.
13 .\" 2. Redistributions in binary form must reproduce the above copyright
14 .\" notice, this list of conditions and the following disclaimer in the
15 .\" documentation and/or other materials provided with the distribution.
16 .\" 3. All advertising materials mentioning features or use of this software
17 .\" must display the following acknowledgement:
18 .\" This product includes software developed by Joerg Wunsch
19 .\" 4. The name of the developer may not be used to endorse or promote
20 .\" products derived from this software without specific prior written
23 .\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
24 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 .\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 .\" $FreeBSD: src/usr.sbin/pcvt/vgaio/vgaio.8,v 1.6.2.7 2003/03/11 22:31:30 trhodes Exp $
35 .\" $DragonFly: src/usr.sbin/pcvt/vgaio/Attic/vgaio.8,v 1.2 2003/06/17 04:29:59 dillon Exp $
36 .\" -hm updated 31.12.94
43 .Nd perform input/output on a Video Graphics Array
52 is used to perform register-level input/output on a Video Graphics Array.
53 Since some of the sequences required to access those registers are very
56 cares of all the things necessary and allows the user to access the
57 registers of several register groups with their symbolic names.
59 .Bl -tag -width 10n -offset indent
61 Turn on the grammar parser debugger.
64 The command language of
66 constitutes of some very simple tokens and rules.
68 line by line as they are entered.
69 Each line may contain any number of
70 semicolon-separated input/output commands.
72 Symbolic register names look like:
74 .D1 Ao Em reggroup Ac Ns Aq Em regnumber
78 being any hexadecimal number
91 .Em Attribute controller ,
93 .Em Graphics controller ,
94 .Em Miscellaneous Output Register ,
96 .Em Timing sequencer ,
99 An input instruction has the form
101 .D1 Ao Em regname Ac \&?
105 to output a line like
106 .Bd -ragged -offset indent
108 .No = 0x Ns Aq Em number
111 An output instruction looks like
112 .Bd -ragged -offset indent
117 Spaces or Tabs between the
121 or any of the other tokens are ignored.
122 They are not required anyway.
126 needs a single unused argument to satisfy the syntax :-) (-hm).
128 The caller must have uid 0 in order to gain the required access to
131 This program is considered
133 It has been developed in order to simplify the process of developing other
134 software that needs to program the Video Graphics Array.
136 Remember, to use this program, your kernel has to be compiled with XSERVER
139 The program has been contributed by
142 .Aq joerg_wunsch@uriah.sax.de .