Building this project requires a few prerequisite tools that stem from the GNU/Linux world, such as:

• gcc (c compiler)
• make (used to execute Makefile targets/recipes to perform various build-related tasks)
• ghdl (vhdl simulator)
• ophis (8-bit cross compiler)
• git (the version-control tool used by this project, and by several of its prerequisite projects)

So if you are predominantly a windows developer and want to contribute to the project, but feel a bit overwhelmed at the thought of jumping ship to Linux, then installing Cygwin in your Windows environment can be a good compromise.

This walkthrough will try guide you through how it's done.

• Download Cygwin from their web-site:
  • https://cygwin.com/install.html
• I picked the 32-bit installer for my 32-bit winxp VM (setup-x86.exe), but you may prefer to use a 64-bit install (setup-x86_64.exe)
  • NOTE: Please remember the path where you download this file on your pc, as you can re-run the setup exe multiple times to install additional packages later on.
  • 
• Run the setup exe, the wizard begins, click “Next”
  • 
• Stick with the default option of “(x) Install from Internet”
  • Then click “Next”
  • 
• Stick with the default install directory (“C:\cygwin”) and click “Next”
  • 
• Stick with the defaults on this page too:
  • 
• Use whatever style internet connection suits your situation.
  • For most home users, “(x) Direction Connection” should be sufficient
  • If you are installing from work and your workplace has a proxy, you might have to use the other options.
  • Then click “Next”
  • 
• pick out a suitable mirror to download from
  • I was lazy and chose the first one on the list ;)
  • You might prefer to use a mirror closer to your geographic location
  • Click “Next”
  • 
• In the “Search” bar at the top, type “make”
  • Expand the “Devel” group
  • In the search results, mouse-click the item called “make: The GNU version of the 'make' utility”
  • A little “[X]” box should appear, indicating that it will be installed
  • This is a good time to search for install any other nice gnu/linux tools you like (openssh, vim, etc… perhaps even git, git-gui and gitk, if you like)
  • If you realise you want more later, just re-run the setup exe again, go through the wizard and add more at this step
  • I will provide a more definitive list of required packages in a section below later
  • Click “Next”
  • 
• Stick with the default “(x) Select required packages (RECOMMENDED)”
  • then click “Next”
• Patiently wait for it all to install… :)
• On the final screen:
  • check the “(x) Create icon on Desktop” checkbox
  • check the “(x) Add icon to Start Menu” checkbox
  • click “Finish”
• 

You can now run cygwin from “Start Menu » Programs » Cygwin » Cygwin Terminal”:

This refers to Michael Martin's Ophis Assembler.

It is a cross-compiler for the 6502-family of processors. Paul has tweaked it so that it can also support his new 4502 processor.

• You'll need to grab it from Paul's github fork of Ophis:
  • “Ophis @ 98ffd2a”
    • https://github.com/gardners/Ophis/tree/98ffd2af95d1a4a1b9dac180c0bdf681f815d47a
• It also needs to be housed in a path that relates to where your mega65 code is located, so that mega65 code can see it.

TODO: Provide more detailed steps for this, just placeholder stuff for now.

GHDL is a vhdl simulator, allowing you to assess how the vhdl code behaves without having to wait an hour or so for the bitstream to build/synthesise.

It also needs to be built from the source, so here are some steps for getting it done.

Run the cygwin setup exe and install the following:

• gcc-g++
• gcc-ada
• gmp-devel
• mpfr-devel
• libmpc-devel
• wget
• git

• cd ~/Downloads
• wget http://mirror.aarnet.edu.au/pub/gnu/gcc/gcc-4.9.3/gcc-4.9.3.tar.gz
• mkdir gcc
• cd gcc
• tar xvf ../gcc-4.9.3.tar.gz
  • (wait patiently for it all to decompress)

• cd ~/Downloads
• git clone http://git.code.sf.net/p/ghdl-updates/ghdl-updates.git ghdl-updates
• cd ghdl-updates
• ./configure –with-gcc=$HOME/Downloads/gcc/gcc-4.9.3
• make copy-sources

• cd ~/Downloads/gcc/
• mkdir gcc-objs; cd gcc-objs
• ../gcc-4.9.3/configure –prefix=/opt/gcc-4.9.3 –enable-languages=c,vhdl –disable-bootstrap –disable-lto –disable-multilib
• make -j2
• make install
• rm /usr/bin/ghdl
• ln -s /opt/gcc-4.9.3/bin/ghdl.exe /usr/bin/ghdl
• As a test, try typing “ghdl –disp-config”
• take a look at the output, and assure that there's no text anywhere that says “ghdl: installation problem:”. If not, your ghdl exe is good to go! :)

• cd “$HOMEPATH/My Documents/mega65”
• make simulate
• this churns away at quite a lot of *.vhdl files this time, no errors given
• then you will get a “cpu_test.exe” file
• Then give Paul's suggestion a try, of:
  • ./cpu_test.exe 2>&1 | grep gs4510 | grep MAP

You should start seeing cpu instructions being outputted to the screen as they are executed.