View the most recent changes for the atari800 port at: atari800.darwinports.com/diff
Scroll down toward the bottom of the page to get installation instructions for atari800.
The raw portfile for atari800 2.1.0 is located here:
http://atari800.darwinports.com/dports/emulators/atari800/Portfile
Find related portfiles with the unique DarwinPorts.com search feature.
Check for any related Fink projects here: pdb.finkproject.org/pdb/package.php/atari800

# -*- coding: utf-8; mode: tcl; tab-width: 4; truncate-lines: t; indent-tabs-mode: nil; c-basic-offset: 4
The atari800 Portfile 58210 2009-09-24 06:56:08Z ryandesign macports.org $
# vim: set fileencoding=utf-8 tabstop=4 shiftwidth=4 softtabstop=4 noexpandtab filetype=tcl :

PortSystem 1.0

Name: atari800
Version: 2.1.0
Revision: 2
Platform: darwin
Category: emulators
Maintainers: krischik
Description: Atari 800 emulator
Long Description: atari800 is an emulator of the classic Atari 800 8bit computer.

Homepage: http://atari800.sourceforge.net/
Master Sites: sourceforge::prog macports:atari800:appbundles

set patchversion 52737
set prog atari800-${version}.tar.gz
set rom xf25.zip
set appbundles atari800-appbundles-r${patchversion}.tar.gz
set share atari800-share-r${patchversion}.tar.gz

distfiles ${prog}:prog ${rom}:prog ${share}:appbundles ${appbundles}:appbundles

extract.only ${prog} ${share} ${appbundles}

Checksums: ${prog} md5 53fdbaad6cb7752fb35895c6375ac9a7 sha1 3888ad49718bb5e1232fb544375bb635654b5ca5 rmd160 c793855b27843975fcf04fea47c49499909b49ee ${rom} md5 4dc3b6b4313e9596c4d474785a37b94d sha1 e65923fd3a4845c1c72d1677db0fda969187eb42 rmd160 e3960898223dd4d1b9a9cc5cfb1251bd726ea5a7 ${share} md5 ed8858c0588f9cdf0fc0f9115192b2b2 sha1 270ca8cccb0295bfe3189530687234c1368ec189 rmd160 d8ef85ece43ac90aa966eb0bb3e811c02f0db64d ${appbundles} md5 b1328ea5cacb72745fbbb93823a1d2c5 sha1 b9ffbdfc14810fc211250b716f318a30a6adf632 rmd160 f6a98b558f01e4c4fd078c106e6862436094fa3d

depends_lib path:lib/pkgconfig/sdl.pc:libsdl port:libpng port:libsdl_image port:libsdl_sound

configure.args --target="sdl" --mandir='\${prefix}/share/man' --datadir='\${prefix}/share/atari800' --sysconfdir='\${prefix}/etc/${name}'
configure.cxxflags-append "-I${prefix}/include"
configure.env-append CFLAGS="-O2 -I${prefix}/include -I${prefix}/include/SDL -D_GNU_SOURCE=1 -D_THREAD_SAFE"

worksrcdir ${name}-${version}/src
use_parallel_build yes

post-extract {
system "unzip -q ${distpath}/${rom} -d ${workpath}/xf25"
}

post-destroot {
xinstall -m 775 -d ${destroot}${prefix}/share/atari800

xinstall -m 444 -W ${workpath}/xf25 ATARIBAS.ROM ATARIOSB.ROM ATARIXL.ROM DEMOS1.XFD DEMOS2.XFD DOS25.XFD MYDOS45D.ATR ${destroot}${prefix}/share/atari800
xinstall -m 444 -W ${workpath}/share-r${patchversion} Setup.command Sparta32g.XFD ${destroot}${prefix}/share/atari800
reinplace s| PREFIX |${prefix}|g ${destroot}${prefix}/share/atari800/Setup.command
}
platform macosx {
post-destroot {
xinstall -d ${destroot}${applications_dir}/Atari-800
foreach comp { Atari-130XE-Basic Atari-130XE-MyDos Atari-1400XL-Basic Atari-1400XL-MyDos Atari-320XE-Basic Atari-320XE-Sparta Atari-800-Basic Atari-800-Dos Atari-800XL-Basic Atari-800XL-Dos} {
copy ${workpath}/appbundles-r${patchversion}/${comp}.app ${destroot}${applications_dir}/Atari-800
reinplace s| PREFIX |${prefix}|g ${destroot}${applications_dir}/Atari-800/${comp}.app/Contents/MacOS/Start.command
}
}
}

If you haven't already installed Darwin Ports, you can find easy instructions for doing so at the main Darwin Ports page.
Once Darwin Ports has been installed, in a terminal window and while online, type the following and hit return:

%  cd /opt/local/bin/portslocation/dports/atari800
%  sudo port install atari800  
Password: 

You will then be prompted for your root password, which you should enter. You may have to wait for a few minutes while the software is retrieved from the network and installed for you. Y ou should see something that looks similar to:

--->  Fetching atari800
--->  Verifying checksum for atari800
--->  Extracting atari800
--->  Configuring atari800
--->  Building atari800 with target all

--->  Staging atari800 into destroot

--->  Installing atari800

- Make sure that you do not close the terminal window while Darwin Ports is working. Once the software has been installed, you can find further information about using atari800 with these commands:

%  man atari800
%  apropos atari800
%  which atari800
%  locate atari800

 Where to find more information: