.TH restorefont 1 "2 Aug 1997" "Svgalib (>= 1.2.11)" "Svgalib User Manual"
.SH NAME
restorefont \- save or restore the SVGA font for textmode.
.SH SYNOPSIS

.BI "restorefont {-r|-w} " filename

.SH DESCRIPTION
The font used by SVGA when in textmode is written to or restored from
.IR filename
using the
.BR vga_gettextfont "(3) and "
.BR vga_puttextfont (3)
functions.

.SH FILE FORMAT
The VGA font file
.I filename
has the following format:

.RS
.BR Offset:
.br
.BR "   0 -   31  " "Character 0"
.br
.BR "    ...      " "    ..."
.br
.BR "8164 - 8195  " "Character 255"
.RE

Each row of a character bitmap is stored as a byte (8 pixels).
The space that is left from the 32-byte buffer for each character
is ignored, e.g. a 16 line font uses only offsets 0 - 15 of each character.

Linux textmode screen resolutions:

.BR 80x25 "    16 line font  400 scanlines"
.br
.BR 80x28 "    14 line font  400 scanlines"
.br
.BR 80x50 "     8 line font  400 scanlines"

The font sizes and resolutions of extended textmodes depend on the
video card type and BIOS:

.BR 132x25 "   14 line font  350 scanlines (ugly)"
.br
.BR 132x25 "   16 line font  400 scanlines"
.br
.BR 132x43 "    8 line font  350 scanlines (use fix132x43 to fix/improve)"
.br
.BR 132x50 "    8 line font  400 scanlines"
.br

Using a font that has less lines per character than the textmode works, but
the characters are smaller. Using a font that is bigger than the textmode
font results in the bottom part of characters being cut off.

The svgalib distribution contains sample fonts with 8, 14 and 16 line characters
in the files
.IR utils/font8 ", " utils/font14 ", and " utils/font16 .

The
.BR convfont
(1) program can be used to convert fonts straightforwardly stored 
character-after-character (i.e. each character only uses 8/14/whatever
bytes), to the 32-byte per character format that
.B restorefont
requires.

The purpose of this program is usually to recover from a crashed console due to an
svgalib, Xfree or other program bug. First save the state of the SVGA card when on a
text console. After the crash restore this state. The
.BR savetextmode (1)
and
.BR textmode (1)
script makes this procedure very easy.

The national/fontpak packages, which include kernel patches, allow different
textmode fonts to be used in different virtual consoles. These have been
superseded by the kbd package (in the kernel since ages). See the
.BR setfont (8)
utility of the kbd package as a starting point.

Recent kernels support up to 2 fonts with 512 chars each. Recent versions
of svgalib take this into account and extend the size of the datafile accordingly.

.SH OPTIONS
.TP
.BI "-w " filename
write the font to the file
.IR filename .
.TP
.BI "-r " filename
restore the font from the file
.IR filename .

.SH SEE ALSO
.BR svgalib (7),
.BR vgagl (7),
.BR libvga.config (5),
.BR setfont (8),
.BR vga_gettextfont (3),
.BR vga_puttextfont (3),
.BR dumpreg (1),
.BR convfont (1),
.BR fix132x43 (1),
.BR restoretextmode (1),
.BR restorepalette (1),
.BR runx (1),
.BR savetextmode (1),
.BR setmclk (1),
.BR textmode (1).
.SH AUTHOR

This manual page was edited by Michael Weller <eowmob@exp-math.uni-essen.de>. The
exact source of the referenced utility as well as of the original documentation is
unknown.

It is very likely that both are at least to some extent are due to
Harm Hanemaayer <H.Hanemaayer@inter.nl.net>.

Occasionally this might be wrong. I hereby
asked to be excused by the original author and will happily accept any additions or corrections
to this first version of the svgalib manual.