Task: Find Easter eggs in several Atari home computer games
Needed: Dig Dug and/or Donkey Kong cartridges
Time: 15-60 minutes
Introduction
There are several Atari home computer games that have Easter eggs left by the programmers. I list here three of these that I personally verified on my own Atari 800 system. The first one, Dig Dug, is super easy and quick. The second one, Super Breakout, takes just a few seconds. The third one, Donkey Kong, took me at least 30 minutes with about 5-6 tries to get it. It requires a relatively complex set of steps compared to Dig Dug. The Donkey Kong egg was only discovered in 2009 after 26 years and required someone digging through the source code to piece it together. Here is an Engadget article about it.
Instructions
Dig Dug
This one is super easy and only takes a few seconds. First, plug your joystick into port #4. Second, press the Option key while holding down the fire button. You will see “The Secret Message” appear on the screen. This one only works with the original release of the Dig Dug cartridge. I have two Dig Dug cartridges in my collection and fortunately one of them was an original.
Super Breakout
This one is also super easy. Simply press shift-control-I from the main screen to view the egg. You will see “I love Susie and Benjy too” at the bottom of the screen.
Donkey Kong
The first thing you need to do for the Donkey Kong Easter egg is attain a score of 33,XXX and for it to be the high score. Scores of 37,XXX, 73,XXX, and 77,XXX are also supposed to work but I didn’t verify these. Don’t worry about the hundreds and tens. They can be anything (X). Next, you need to kill off your remaining Marios. The key here is that the last death needs to be due to falling. When the title screen comes back press the option key three times to set it to difficulty four. Wait for the cut scene with Donkey Kong jumping on the beams. When this is over the title screen will reappear with the initials LMD at the bottom. These are the initials for the programmer Landon M. Dyer. This is the egg! I will list a tip in the comments below for accomplishing this. If you want to figure out how to do this yourself then skip that section. Below is a photo the title screen with the initials LMD at the bottom. This photo is of a Sakata monitor connected to my Atari 800.

Comments (Spoiler)
What I learned is that you need to sandbag your score on Donkey Kong in the first several levels. In other words, let the time run down on a few of them and maybe avoid some of the prizes. If you don’t do this you will likely end up with 33,XXX points on the pie factory level and this one is difficult to finish on. By sandbagging your score you can get by this one and hit 33,XXX on the elevator level which is next. This is the ideal one to end on because it is really easy to kill Mario off by falling.
As an addition note, here is Landon Dyer’s blog and Facebook page. Also, he was interviewed by Kevin Savetz in 2016 for the Antic podcast.