eMac Monitor Tool

This tool allows you to configure an emac monitor using i2c. I'm using the interface detailed here:

https://en.wikibooks.org/wiki/How_to_modify_an_eMac_to_use_as_an_external_monitor

It turns out this is available on /dev/i2c-0. It lets you set horizontal/vertical position/size, etc. 
It isn't entirely clear what all the controls do, but it's good for centering your display.

It turns out that you can't read the values back, so I have had to take a guess at roughly "OKish"
initial values. As a result the revert button takes you back to these OKish values, which could 
look a bit odd. 

I also found that you can read a bunch of other registers from device 0x53 on the bus.. address 0x0 
to 0x1d have values that are not 0xff, but I don't know what they are for. They aren't the initial 
values for the monitor config and changing them doesn't have any noticeable effect.

TODO is to allow saving/loading of the settings, and I guess it might be nice to automatically set 
the config at boot. But as long as I can set the horizontal/vertical position and size I am not too 
worried about this at present.

BSD licensed. See the code.

Installation

Dependencies are i2c-dev and gtk+3.0. On debian (and probably debian based) systems these can be installed with:

apt-get install libi2c-dev i2c-tools libgtk-3-dev 

Then you can just run:

make
sudo make install

The binary generated is called "emt" and will be install in /usr/sbin.