Editing Space Invaders (section)

==Development==
''Space Invaders'' was developed by Japanese designer [[Tomohiro Nishikado]], who spent a year designing it and developing the necessary [[Computer hardware|hardware]] to produce it.<ref name="GI-177">{{Cite magazine |date=January 2008 |title=Classic GI: Space Invaders |magazine=[[Game Informer]] |author=<!--Not stated--> |publisher=Game Stop |issue=177 |pages=108–109}}</ref> The game was a response to [[Atari, Inc.]]'s arcade video game ''[[Breakout (video game)|Breakout]]'' (1976). Nishikado wanted to adapt the same sense of achievement and tension from destroying targets one at a time, combining it with elements of target [[shooting games]].<ref name="GI-177" /><ref name="RG-3">{{cite magazine|author=<!--Not stated-->|title=Nishikado-San Speaks|url=https://archive.org/stream/retro_gamer/RetroGamer_003#page/34/mode/2up|magazine=[[Retro Gamer]]|publisher=Live Publishing|issue=3|date=April 15, 2004|page=35}}</ref><ref name="Williams">{{cite book |last1=Williams |first1=Andrew |title=History of Digital Games: Developments in Art, Design and Interaction |date=March 16, 2017 |publisher=[[CRC Press]] |isbn=978-1-317-50381-1 |pages=73–6}}</ref><ref name="auto">{{cite web | url=https://www.theguardian.com/games/2018/jun/04/space-invaders-at-40-tomohiro-nishikado-interview | title=Space Invaders at 40: 'I tried soldiers, but shooting people was frowned upon' | work=The Guardian | date=June 4, 2018 | last1=Freeman | first1=Will }}</ref> The game uses a similar layout to that of ''Breakout'' but with different [[game mechanics]]; rather than bounce a ball to attack static objects, players are given the ability to fire projectiles at moving enemies.<ref>{{cite web |url=https://www.gamedeveloper.com/business/the-history-of-i-pong-i-avoid-missing-game-to-start-industry |title=The History of Pong: Avoid Missing Game to Start Industry |first=Bill |last=Loguidice |author2=Matt Barton |website=[[Gamasutra]] |date=January 9, 2009 |access-date=January 10, 2009 |archive-date=January 12, 2009 |archive-url=https://web.archive.org/web/20090112004852/http://www.gamasutra.com/view/feature/3900/the_history_of_pong_avoid_missing_.php |url-status=live }}</ref>

Nishikado added several interactive elements that he found lacking in earlier video games, such as the ability for enemies to react to the player's movement and fire back, and a [[game over]] triggered by the enemies killing the player (either by getting hit or enemies reaching the bottom of the screen) rather than simply a timer running out.<ref name="RG-3"/> He replaced the timer, typical of arcade games at the time, with descending aliens who effectively served a similar function, where the closer they came, the less time the player had left.<ref name="Williams"/>

Early enemy designs included tanks, combat planes, and battleships.<ref name="GI-177" /><ref name="auto"/> Nishikado, however, was not satisfied with the enemy movements; technical limitations made it difficult to simulate flying.<ref name="GI-177" /><ref name="Edge-Taito">{{Cite magazine |date=October 2005 |title=The Creation of Space Invaders |magazine=[[Edge (magazine)|Edge]] |issue=154 |author1=Kiphshidze, N |author2=Zubiashvili, T |author3=Chagunava, K |pages=7–13}}</ref> Humans would have been easier to simulate, but the designer considered shooting them immoral.<ref name="Edge-Taito" /><ref name="1UP-10things">{{cite web |url=http://www.1up.com/do/feature?cId=3168373 |archive-url=https://web.archive.org/web/20090226064943/http://www.1up.com/do/feature?cId=3168373 |url-status=dead |archive-date=February 26, 2009 |title=Ten Things Everyone Should Know About Space Invaders |website=[[1UP.com]] |author=Edwards, Benj |access-date=July 11, 2008}}</ref> Nishikado also said that shooting people was frowned upon.<ref name="auto"/> After seeing the release of the 1974 [[anime]] ''[[Space Battleship Yamato]]'' in Japan,<ref>{{cite magazine |title=Tomohiro Nishikado – 2000 Developer Interview |magazine=Game Maestro |date=2000 |volume=1 |url=http://shmuplations.com/nishikado/ |access-date=March 4, 2018 |archive-date=June 8, 2019 |archive-url=https://web.archive.org/web/20190608174731/http://shmuplations.com/nishikado/ |url-status=live }}</ref><ref>{{cite book |last=Kohler |first=Chris |title=Power-Up: How Japanese Video Games Gave the World an Extra Life |date=2016 |publisher=[[Courier Dover Publications]] |isbn=9780486801490 |page=19 |url=https://books.google.com/books?id=lD4fDQAAQBAJ&pg=PA19}}</ref> and seeing a magazine feature about ''[[Star Wars (film)|Star Wars]]'' (1977), he thought of using a space theme.<ref name="GI-177" /><ref name="RG-3" /> Nishikado drew inspiration for the aliens from a novel by [[H. G. Wells]], ''[[The War of the Worlds]]'', and created initial [[bitmap]] images after the octopus-like aliens.<ref name="GI-177" /><ref name="RG-3" /><ref name="Edge-Taito" /><ref name="auto"/> Other alien designs were modeled after squids and crabs.<ref name="GI-177" /><ref name="Edge-Taito" /><ref name="auto"/> The game was originally titled ''Space Monsters'' after a popular song in Japan at the time, "<!--[[-->Monster<!--Need verification (Pink Lady song)| ]]-->", but was changed to ''Space Invaders'' by the designer's superiors.<ref name="GI-177" /><ref name="RG-3" />

===Hardware===
{{multiple image
<!--image 1-->| image1            = Space Invaders.JPG
| caption1          = Cocktail [[table arcade cabinet]]
<!--image 2-->| image2            = Tilt byte - 10.jpeg
| caption2          = A modified Space Invaders [[arcade cabinet]]
}}

Nishikado designed his own custom hardware and development tools for ''Space Invaders''.<ref name="GI-177" /><ref name="Edge-Taito" /> It uses an [[Intel 8080]] [[central processing unit]] (CPU), displays [[raster graphics]] on a [[CRT monitor]] using a [[bitmap]]ped [[framebuffer]], and uses [[monaural sound]] hosted by a combination of [[analog circuitry]] and a [[Texas Instruments SN76477]] [[sound chip]].<ref name="KLOV-SI">{{cite web |url=http://www.klov.com/game_detail.php?game_id=9662 |title=Space Invaders Videogame by Bally Midway (1978) |publisher=[[Killer List of Videogames]] |access-date=May 12, 2008 |archive-date=November 25, 2010 |archive-url=https://web.archive.org/web/20101125042142/http://www.arcade-museum.com/game_detail.php?game_id=9662 |url-status=live }}</ref><ref name="1UP-10things" /><ref>{{cite book |title=The Art of Game Worlds |first=Dave |last=Morris |page=166 |publisher=[[HarperCollins]] |isbn=0-06-072430-7 |year=2004}}</ref> The adoption of a microprocessor was inspired by ''[[Gun Fight]]'' (1975), [[Midway Games|Midway's]] microprocessor adaptation of Nishikado's earlier [[discrete logic]] game ''[[Western Gun]]'', after the designer was impressed by the improved graphics and smoother animation of Midway's version.<ref>{{citation |author=Chris Kohler |year=2005 |title=Power-Up: How Japanese Video Games Gave the World an Extra Life |chapter=Chapter 2: An Early History of Cinematic Elements in Video Games|chapter-url=https://books.google.com/books?id=auMTAQAAIAAJ |page=19 |publisher=[[BradyGames]] |isbn=0-7440-0424-1 |access-date=March 27, 2011}}</ref> '' Space Invaders'' also adopted the multi-chip [[barrel shifter]] circuit first developed by Midway for ''Gun Fight'', which had been a key part of that game's smoother animation. This circuit allowed the 8080 CPU to shift pictures in the graphics framebuffer faster than it could using only its own native instructions.<ref>In ''Gun Fight'', the bit-shifts performed by this circuit appear on the screen as horizontal offsets. The circuit in ''Space Invaders'' works the same, but the bit shifts it does are now '''vertical''' from the player's perspective because the entire screen has been rotated by 90 degrees.</ref>

Despite the specially developed hardware, Nishikado was unable to program the game as he wanted—the Control Program board was not powerful enough to display the graphics in color or move the enemies faster—and considered the development of the hardware the most difficult part of the process.<ref name="GI-177" /><ref name="Edge-Taito" /> While programming, Nishikado discovered that the processor was able to [[Rendering (computer graphics)|render]] each frame of the alien's animation graphics faster when there were fewer aliens on the screen. Since the alien's positions updated after each frame, this caused the aliens to move across the screen at an increasing speed as more and more were destroyed. Rather than design a compensation for the speed increase, he decided that it was a [[feature, not a bug]], and kept it as a challenging [[gameplay]] mechanism.<ref name="RG-3" />

Taito released ''Space Invaders'' in July 1978.<ref name="FT"/> They released both an [[Arcade cabinet#Upright cabinets|upright arcade cabinet]] and a so-called [[Arcade cabinet#Cocktail cabinets|"cocktail-table" cabinet]]; following its usual practice, Taito named the cocktail version ''T.T. Space Invaders'' ("T.T." for "table-top"). Midway released its upright version a few months later and its cocktail version several months after that. The cabinet artwork featured large [[humanoid]] [[monster]]s not present in the game; Nishikado attributes this to the artist basing the designs on the original title of "''Space Monsters''", rather than referring to the actual in-game graphics.<ref name="GI-177" /> In the upright cabinets, the graphics are generated on a hidden CRT monitor and reflected toward the player using a [[semi-transparent mirror]], behind which is mounted a plastic cutout of a [[Natural satellite|moon]] bolted against a painted starry background. The backdrop is visible through the mirror and thus appears "behind" the graphics.<ref name="RG-41" /> Both Taito's and Midway's first Space Invaders versions had black-and-white graphics with a transparent colored overlay using strips of orange and green [[cellophane]] over certain portions of the screen to add color to the image. Later Japanese releases used a rainbow-colored cellophane overlay,<ref name="RG-41" /> and these were eventually followed by versions with a color monitor and an electronically generated color overlay.<ref name="RG-41" />

===Music===
{{Listen
 |filename     = Space Invaders Music.ogg
 |title        = Space Invaders music
 |description  = The game's signature looping four-note bassline, as heard during gameplay
}}
Despite its simplicity, the music to ''Space Invaders'' was revolutionary for the gaming industry of the time. Video game scholar Andrew Schartmann identifies three aspects of the music that had a significant impact on the development of game music:
# Whereas video game music prior to ''Space Invaders'' was restricted to the extremities (i.e., a short introductory theme with game-over counterpart), the alien-inspired hit featured ''continuous music''{{tsp}}{{mdash}}{{tsp}}the well-known four-note loop, consisting of the first four notes of the descending D [[Natural minor scale|minor natural scale]]{{tsp}}{{mdash}}{{tsp}}throughout, uninterrupted by sound effects: "It was thus the first time that sound effects and music were superimposed to form a rich sonic landscape. Not only do players receive feedback related directly to their actions through sound effects; they also receive stimulus in a more subtle, non-interactive fashion through music."<ref name="MaestroMario">Schartmann, Andrew. [http://thoughtcatalog.com/book/maestro-mario-how-nintendo-transformed-videogame-music-into-an-art/ Maestro Mario: How Nintendo Transformed Videogame Music into an Art.] {{Webarchive|url=https://web.archive.org/web/20130823064005/http://thoughtcatalog.com/book/maestro-mario-how-nintendo-transformed-videogame-music-into-an-art/ |date=August 23, 2013 }} New York: Thought Catalog, 2013.</ref>
# The music interacts with on-screen animation to influence the emotions of the player: "That seemingly pedestrian four-note loop might stir us in the most primitive of ways, but that it stirs us at all is worthy of note. By demonstrating that game sound could be more than a simple tune to fill the silence, ''Space Invaders'' moved video game music closer to the realm of art."<ref name="MaestroMario" />
# The music for ''Space Invaders'' popularized the notion of variability—the idea that music can change in accordance with the ongoing on-screen narrative. The variable in ''Space Invaders'', the [[tempo]], is admittedly simple, but its implications are not to be underestimated. "Over the years, analogous strategies of variation would be applied to pitch, rhythm, dynamics, form, and a host of other parameters, all with the goal of accommodating the nonlinear aspect of video games."<ref name="MaestroMario" />
{{Quotation|At the deepest of conceptual levels, one would be hard-pressed to find an arcade game as influential to the early history of video game music as ''Space Invaders''. Its role as a harbinger of the fundamental techniques that would come to shape the industry remains more or less unchallenged. And its blockbuster success ensured the adoption of those innovations by the industry at large.|Andrew Schartmann, ''Thought Catalog'' (2013)}}

''[[Next Generation (magazine)|Next Generation]]'' editor Neil West also cited the ''Space Invaders'' music as an example of great video game art, commenting on how the simple melody's increasing tempo and synchronization with the enemies' movement chills and excites the player.<ref>{{cite magazine|last=West|first=Neil|date=November 1997|title=The Way Games Ought to Be...: Great Videogame Art (with No Pictures)|url=https://archive.org/details/NEXT_Generation_35/page/n157/mode/2up|magazine=[[Next Generation (magazine)|Next Generation]]|issue=35|page=157}}</ref>