Company: Atari
Model #:
Unknown (possibly Brad Stewart)
Year: 1979
Uses stereo sound


When programmer Brad Stewart (of 2600 Asteroids fame) did an interview back in 2001, he mentioned working on two unreleased 2600 games during his time at Atari.  One of these games was Morse Code Tutor and the other was an unnamed Battleship style game.  While Morse Code Tutor finally surfaced in 2014, the Battleship game was thought to be lost as Brad didn't have a copy of it anymore.  Fast forward to 2022 when a previously unknown prototype labeled Sonar was found in the collection of Jim Snyder (who worked in research and development at Atari in the early 80's) by Alvaro Arroyo. 

Once the game was analyzed it was thought to be Brad's missing Battleship game.  However when shown some video of the game in action Brad said while it may have looked like a game he wrote, he didn't recognize the sound and he wasn't sure if it was indeed his lost Battleship game.  Brad also didn't think that his game got much further than some preliminary code and a design document.  So it would appear that either this is Brad's lost Battleship game that someone finished after he wrote some of the code and moved onto another project, or that this is a completely unrelated game that just happened to share the same theme.  In the early hectic history of Atari either theory seems equally plausible.

Although Sonar was originally thought to be a 2600 version of Battleship, it's actually a bit different than that.  In his interview Brad describes it as a "Version of Battleship" which is a bit more accurate.  Since Battleship requires each player to have their own private screen (otherwise each player could see where their opponent has hidden their ships), the programmer had to come up with a different idea for a game where each player shares the same screen.  Their solution?  Have the computer hide the ships and have each player race around the screen to find them in real time.  Each successful hit scores the player 5 points and the player who scores the most points after all the ships have been discovered (as indicated by the blue bar at the top of the screen) wins the game.

If the above description makes Sonar sound like a button mashing action game, you'd be wrong.  Sonar has four different  options to give the game a bit more strategy. 

Limited Charges - In this variation each ship can only drop 5 depth charges (indicated by the dashes on the top of the playfield) before running out.  After they run out they will need to wait until the other player drops all of their depth charges before their supply is refilled.  This variation allows players to take their time in finding ships.

Miss Penalty - Each time a player bombs an empty square it costs them 2 points.

Invisible - The board isn't marked (the square doesn't turn green) when a player drops a depth charge .  This makes it harder to remember if you've already bombed a square or not.  Combined with the Miss Penalty variation, this can be a real score killer.

Mines - Mines are hidden on the board in addition to the ships.  If you bomb a hidden mine you lose 5 points.

The matrix below shows the various rules for all 16 variations

So with all the point penalties in the game, how are players supposed to find ships when mindlessly bombing squares will quickly decrease their scores to zero?  The answer is right there in the title!  When a player is in one square of a ship they'll hear a sonar sound.  This sound helps the player try and pinpoint the location of each ship.  Depending on the position of the difficulty switch, the sonar radius is either a complete square around the ship (position A) or only at the top/bottom/left/right (position B).  But how would each player know which sonar ping was for their ship you ask?  The answer is stereo!  The sound for each player was to come out of separate speakers so they could listen to their own sonar.  In fact Sonar is one of only three games that was programmed with stereo sound (Combat and Air-Sea Battle are the other two).  This is because the 2600 was originally supposed to have two speakers in the console itself where sound would come out instead of going through the TV (Heavy Sixer models still have mounts for the speakers inside the case).  Atari decided to change this shortly before the 2600 launched, which would explain why only the two launch titles were programmed with this in mind.  However this doesn't explain why a game programmed in 1979 would make use of stereo as the sound would come out mono on the TV anyway (unless the system was specifically modded to play stereo).  Not only that, but unless the speakers were sufficiently far enough away from each other it would almost be impossible to tell which sonar sound belonged to which player.  This may mean that programming on Sonar started much earlier than 1979.

Although Sonar is an almost complete prototype, there are still a few bugs and missing features in the game.  The biggest bug is that if the player has the difficulty switch in the A position (full sonar scan) the screen will briefly roll due to the kernel using up too much CPU time.  The display will quickly fix itself but the constant flickering makes the game hard to play.  The second issue is that the ships and mines are not randomized.  There is only one pre-programmed map that is always used.  by looking at the game code it would appear that randomized boards were planned but that the feature had not yet been implemented when game development was stopped.

So why was Sonar never finished?  No one is quite sure, but the most obvious explanation is that the sonar gimmick relies on the 2600 being able to produce stereo sound which was removed from the system before it shipped.  Other theories are that the programmer was pulled off the game to work on higher priority projects or that it simply wasn't considered fun enough for Atari to publish.  No matter what the real reason is for Sonar's untimely demise, it's a fun little game that deserves a second look.

Special thanks to Alvaro Arroyo for finding, dumping, and sharing this prototype and to Thomas Jentzsch for helping figure out how to play the game!

Version Cart Text Description
?/??/79 Sonar
Almost complete


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