Editing Robotron: 2084 (section)

== Development ==
{{multiple image | total_width = 250 | image1 = Eugene Jarvis at CA Extreme 2016.jpg | alt1 = A smiling man wearing a grey polo shirt | image2 = Larry DeMar at CA Extreme 2016.jpg | alt2 = A man wearing a white t-shirt speaking into a handheld microphone | footer = Eugene Jarvis (left) and Larry DeMar (right) created the game for Williams Electronics. The pair drew inspiration from previous games and  George Orwell's novel ''Nineteen Eighty-Four''.}}

''Robotron: 2084'' features [[Beat (acoustics)|monaural]] sound and [[raster graphics]] on a 19-inch [[CRT monitor]].<ref name="KLOV"/> It uses a [[Motorola 6809]] [[central processing unit]] that operates at 1M[[Hertz|Hz]].<ref name="Halcyon"/> Sounds are generated in software, with the same routines as in other Williams games of the era. The game uses a priority scheme to determine which sounds to play on a single channel.<ref name="gamesTM-36"/> A custom [[blitter]] chip generates the on-screen objects and visual effects. It transfers memory faster than the CPU, allowing the game to simultaneously animate a large number of objects.<ref name="Halcyon"/><ref>{{cite book | title = Handbook of Computer Animation | first = John | last = Vince | publisher = [[Springer Science+Business Media]] | page = 4 | isbn = 1-85233-564-5 | year = 2002}}</ref>

The game was developed in six months by [[Eugene Jarvis]] and [[Larry DeMar]], founders of [[Vid Kidz]].<ref name="Halcyon">{{cite book | title = Halcyon Days: Interviews with Classic Computer and Video Games Programmers | editor = James Hague | year = 1997 | chapter = Eugene Jarvis | publisher = Dadgum Games | chapter-url = https://dadgum.com/halcyon/BOOK/JARVIS.HTM | title-link = Halcyon Days (book)}}</ref> Vid Kidz served as a consulting firm that designed games for Williams Electronics (part of [[WMS Industries]]), whom Jarvis and DeMar had previously worked for.<ref name="Ultimate-1">{{cite book | title = [[Ultimate History of Video Games]] | first = Steven | last = Kent | authorlink = Steven L. Kent | pages = 220–222 | chapter = The Fall | publisher = [[Three Rivers Press]] | isbn = 0-7615-3643-4 | year = 2001}}</ref> The game was designed to provide excitement for players; Jarvis described the game as an "athletic experience" derived from a "physical element" in the two-joystick design. ''Robotron: 2084''{{'}}s gameplay is based on presenting the player with conflicting goals: avoid enemy attacks to survive, defeat enemies to progress, and save the family to earn points.<ref name="Fever-2">{{cite book | title = Arcade Fever: The Fan's Guide to The Golden Age of Video Games | chapter = The Creator | first = John | last = Sellers | pages = 52–53 | publisher = [[Running Press]] | date=August 2001 | isbn = 0-7624-0937-1}}</ref> It was first inspired by [[Stern (game company)|Stern]] Electronics' 1980 arcade game ''[[Berzerk (video game)|Berzerk]]'' and the [[Commodore PET]] computer game ''[[Chase (video game)|Chase]]''. ''Berzerk'' is a shooting game in which a character traverses a maze to shoot robots, and ''Chase'' is a [[text-based game]] in which players move text [[Character encoding|characters]] into others.<ref name="Halcyon"/><ref name="Arc-Treasure-1">{{cite video game | title= [[Midway Arcade Treasures]] | developer= [[Backbone Entertainment|Digital Eclipse]] | publisher= [[Midway Games]] | date= 2003-11-18 | platform= [[PlayStation 2]] | level= The Inside Story On Robotron 2084}}</ref>

The initial concept involved a passive main character; the object was to get robots that chased the protagonist to collide with stationary, lethal obstacles.<ref name="Halcyon"/><ref name="gamesTM-36">{{cite journal | journal = [[GamesTM]] | title = Robotron: 2084 Behind the Scenes | issue = 36 | date=October 2005 | author = GamesTM Staff | pages = 146–149}}</ref> The game was deemed too boring compared to other action titles on the market, which led to shooting being added to provide more excitement.<ref name="Halcyon"/><ref name="Retro60">{{cite journal | journal = [[Retro Gamer]] | title = The Making of Robotron: 2084 | first = Craig | last = Grannell | publisher = [[Imagine Publishing]] | issue = 60 | date=March 2009 | pages = 44–47}}</ref> The shooting elements drew inspiration from the 1978 arcade game ''[[Space Invaders]]'', which had previously inspired ''Defender''.<ref>{{cite news | last1=Grannell | first1=Craig | title=Eugene Jarvis on the reality of clones in the games industry | url=http://reverttosaved.com/2008/07/30/eugene-jarvis-on-the-reality-of-clones-in-the-games-industr/ | access-date=19 May 2021 | work=Revert to Saved | date=July 30, 2008}}</ref>

The dual-joystick design was developed by Jarvis, and resulted from two experiences in Jarvis's life: an [[Traffic collision|automobile accident]] and playing ''Berzerk''. Prior to beginning development, Jarvis injured his right hand in an accident—his hand was still in a cast when he returned to work, which prevented him from using a traditional joystick with a button. While in rehabilitation, he thought of ''Berzerk''.<ref name="Ultimate-1"/><ref name="Arc-Treasure-1"/> Though Jarvis enjoyed the game and similar titles, he was dissatisfied with the control scheme; ''Berzerk'' used a single joystick to move the on-screen character and a button to fire the weapon, which would shoot in the same direction the character was facing.<ref name="Ultimate-1"/><ref name="Retro60"/> Jarvis noticed that if the button was held down, the character would remain stationary and the joystick could be used to fire in any direction.<ref name="Halcyon"/><ref name="Retro60"/> This method of play inspired Jarvis to add a second joystick dedicated to aiming the direction projectiles were shot.<ref name="Retro60"/> Jarvis and DeMar created a prototype using a ''[[Stargate (1981 video game)|Stargate]]'' [[arcade system board]] and two [[Atari 2600 hardware#Controllers|Atari 2600 controllers]] attached to a control panel.<ref name="Halcyon"/><ref name="Ultimate-1"/> In retrospect, Jarvis considers the design a contradiction that blends "incredible freedom of movement" with ease of use.<ref name="gamesTM-36"/>

The developers felt a rescue theme similar to ''[[Defender (video game)|Defender]]''—one of their previous games—was needed to complete the game, and added a human family as a method to motivate players to earn a high score.<ref name="Arc-Treasure-1"/><ref name="Retro60"/> The rescue aspect also created a situation where players had to constantly reevaluate their situation to choose the optimal action: run from enemies, shoot enemies, or rescue humans.<ref name="gamesTM-36"/><ref name="Fever-2"/> Inspired by [[George Orwell]]'s ''[[Nineteen Eighty-Four]]'', Jarvis and DeMar worked the concept of an [[Orwellian]] world developed into the plot. The two noticed, however, that 1984 was approaching, but the state of the real world did not match that of the book. They decided to set the game further in the future, the year 2084, to provide a more realistic timeframe for their version of "[[Big Brother (Nineteen Eighty-Four)|Big Brother]]". Jarvis, a [[science fiction]] fan, based the Robotrons on the idea that computers would eventually become advanced entities that helped humans in everyday life. He believed the robots would eventually realize that humans are the cause of the world's problems and revolt against them.<ref name="Ultimate-1"/>

Jarvis and DeMar [[playtest]]ed the game themselves, and continually tweaked the designs as the project progressed.<ref name="gamesTM-36"/> Though games at the time began to use [[scrolling]] to have larger levels, the developers chose a single screen to confine the action.<ref name="Retro60"/> To instill panic in the player, the character was initially placed in the center of the game's action, and had to deal with projectiles coming from multiple directions, as opposed to previous shooting games such as ''[[Space Invaders]]'' and ''[[Galaxian]]'', where the enemies attacked from a single direction. This made for more challenging gameplay, an aspect Jarvis took pride in.<ref name="Ultimate-1"/> Enemies were assigned to stages in different groups to create themes.<ref name="Halcyon"/> Early stages were designed to be relatively simple compared to later ones. The level of difficulty was designed to increase quickly so players would struggle to complete later stages. In retrospect, Jarvis attributes his and DeMar's average player skills to the game's balanced design. Though they made the game as difficult as they could, the high end of their skills ended up being a good challenge for expert players.<ref name="gamesTM-36"/> The graphics were given a simple appearance to avoid a cluttered game screen, and object designs were made distinct from each other to avoid confusion. Black was chosen as the background color to help characters stand out and reduce clutter.<ref name="Retro60"/>

=== Enemy designs ===
Each enemy was designed to exhibit a unique behavior toward the character; random elements were programmed into the enemies' behaviors to make the game more interesting.<ref name="Halcyon"/><ref name="gamesTM-36"/> The first two designed were the simplest: Electrodes and Grunts. Electrodes are stationary objects that are lethal to the in-game characters, and Grunts are simple robots that chase the protagonist by plotting the shortest path to him.<ref name="Halcyon"/><ref name="Retro60"/> Grunts were designed to overwhelm the player with large groups.<ref name="gamesTM-36"/> While testing the game with the new control system and the two enemies, Jarvis and DeMar were impressed by the gameplay's excitement and fun. As a result, they began steadily increasing the number of on-screen enemies to over a hundred to see if more enemies would generate more enjoyment.<ref name="Halcyon"/><ref name="Retro60"/>

Other enemies were created to add more variety. Large, indestructible Hulks, inspired by an enemy in ''Berzerk'', were added to kill the humans on the stage. Though they cannot be destroyed, the developers decided to have the protagonist's projectiles slow the Hulk's movement as a way to help the player. Levitating Enforcers were added as enemies that could shoot back at the main character; Jarvis and DeMar liked the idea of a floating robot and felt it would be easier to animate. A projectile [[algorithm]] was devised for Enforcers to simulate enemy [[artificial intelligence in video games|artificial intelligence]]. The developers felt a simple algorithm of shooting directly at the protagonist would be ineffective because the character's constant motion would always result in a miss. Random elements were added to make the projectile more unpredictable; the Enforcer aims at a random location in a ten-[[pixel]] radius around the character, and random acceleration curves the [[trajectory]]. To further differentiate Enforcers, Jarvis devised the Spheroid enemy as a robot that continually generated Enforcers, rather than have them already on the screen like other enemies. Brains were conceived as robots that could capture humans and brainwash them into enemies called Progs, and also launch cruise missiles that chase the player in a random zigzag pattern, making them difficult to shoot down. DeMar devised the final enemies as a way to further increase the game's difficulty; Tanks that fire projectiles which bounce around the screen, and Quarks as a tank-producing robot.<ref name="Retro60"/>

In the summer of 2012, Eugene Jarvis wrote a comprehensive evaluation of the Robotron Enemy Dynamics: the game is [[hard-coded]] with 40 waves, whereupon the game repeats wave 21 to 40 over and over until the game restarts back to the original wave 1, once the player completes wave 255. In the same year, Larry DeMar provided details on how to trigger the secret copyright message in ''Robotron''.<ref>{{cite web | url = https://www.youtube.com/watch?v=4UJd2iFuTfY | title = Larry DeMar shows Robotron secret | website = [[YouTube]] | access-date = 2015-08-18 | archive-date = 2015-11-26 | archive-url = https://web.archive.org/web/20151126080839/https://www.youtube.com/watch?v=4UJd2iFuTfY | url-status = dead}}</ref>