                      .........     ........  ....      ...
                         -===.   -===.        ==o=.   .-=.
 ::|:|||||#|#|#####:  .=***=   .*o*o          ****.  =*=  :####|#|#|||||::
                     =###=    -*##*    o**o   ##** .**-
 :::.... . . .     =*o*-      o**o-   =o*o   -o**o-*-   . . . . ...:.:::::
 ::.... . .      o#@@#-...-=. ##@@*-.=@@@-   =@@@@#-       . . . ...:.::::
               -@@@@@@@@@@*.   o#@@@@@@@o     *@@*
                                

 Zgv v2.2 - GIF, JPEG and PBM/PGM/PPM viewer, for PCs with VGA running Linux

       Copyright (C) 1993,1994 Russell Marks for improbabledesigns


This README covers description and use of the programs. See README.src in
the source distribution, or README.bin in the binaries distribution for
other details. (In fact, you should read those first.) CHANGES describes the
changes made since the most recent publicly released version, and CHANGELOG
describes differences between all versions, so if you are upgrading from an
old version, check those files out too. The file BUGS describes known bugs
which may affect your use of the programs.

NB: All documentation files other than this README and the man pages are in
the 'doc' subdirectory.


Distribution and Conditions of Use (License)
--------------------------------------------

These programs, and any output from them, can be freely used and
distributed. No modified versions of any or all of the programs, or
derivative works, may be distributed unless specifically permitted by the
author, with the following exception; if the modification is reverseable and
intended in good faith to aid distribution (common occurances include
using 'tar', compression software, etc.), then it is permitted.  

I supply each of the programs on an 'as is' basis in the hope that they will
be useful but with absolutely no warranty of any kind, and assume no
liability or responsibility for any ill they may cause whatsoever.  


Description of the Programs
---------------------------

'zgv' is a viewer which views GIF87a, GIF89a, JPEG/JFIF and PBM/PGM/PPM
files on a standard VGA and most SVGAs, with a full-screen file selector
front-end. It can also be used as a simple command, by 'zgv filename', which
bypasses the front-end. There are now other options; check the man page, or
try 'zgv -h' for details.

'tnpic' produces a JPEG file containing small versions (thumbnails) of other
picture files. Once the programs are installed, do 'man tnpic' for more
details. (Or if they aren't installed, you could do 'nroff -man
tnpic.1 | less'.) Tnpic does not yet support P?M files.



You should read the man page and the TeX file 'zgv.tex' for more details -
try 'xdvi zgv.dvi', if that doesn't work, just reading 'zgv.tex' as a text
file isn't too painful. Where the TeX file and the man page differ, the man
page should be assumed to be up to date and correct. I'll try to get the TeX
file up to date sometime, but be warned that adding extra bloat to zgv will
take priority. :)

The file '24bit.txt' describes how the 24-bit handling works, hopefully. (I
apologise in advance for the fairly confusing nature of the documentation.)


A note about the previous note about /dev/tty0
----------------------------------------------

Having /dev/tty0 as world-readable is apparently a security hole. Zgv now
uses /dev/tty, which is world-readable, but this isn't a security hole
(trust me, it makes sense). Svgalib from v1.07 uses /dev/console, so you
should compile with that if possible - the binaries are compiled with it. If
you do, or you are using the binaries, you should be able to restrict the
permissions on /dev/tty0 by doing "chmod go-r /dev/tty0" without problems.


Share and enjoy! 

- Russell Marks (rm1ajy2@gre.ac.uk)
