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{{
{{more citations needed|date=October 2017}}
{{Use dmy dates|date=July 2017}}
{{Infobox video game
|title
|image =
|developer = [[Atari, Inc.]]
|publisher = Atari, Inc.▼
|
▲|publisher = Atari
|released = {{vgrelease|NA|April 1980<ref>{{cite web |title=Atari VCS game release dates |url=https://www.atariarchive.org/atari-vcs-game-release-dates/ |website=Atari Archive}}</ref>}}
|platforms = [[Atari 2600]]
}}
'''''BASIC Programming'''''
==Details==
[[File:Basicprogramming.png|thumb|upright=2|Main display]]
The BASIC Programming display was divided into six regions:▼
* '''Program''' where instructions are written (maximum of nine (or eleven) lines of code).▼
* [[Call stack|Stack]] shows temporary results of what your program does. ▼
* [[Variable (programming)|Variables]] displays the values of any variables your program is using. ▼
* '''Output''' displays any output values your program is creating. ▼
* '''Status''' displays the amount of available memory remaining▼
* '''Graphics''' contains two colored squares that can be manipulated by your program.▼
▲* '''Program''' is where instructions are
Input is given through two Atari keypad controllers, which came with special overlays to show how to type the different commands and letters.<ref>[https://atariage.com/controller_page.html?ControllerID=4&SystemID=2600 Controllers - Atari Keypad], Atari KeypadSystem: Atari 2600, Model Number: CX50, ''Sold in pairs, functionally identical to the Kid's Controller and the Video Touch Pad. Included overlays with commands, meant to be used with Basic Programming.''</ref> Programs were restricted to 64 characters in size and 9 lines of code, severely limiting the programs that could be written. Users could disable all windows except Program and keep selecting "New Line" until over nine empty lines had been entered and thus their program could use 11 lines of code using this trick.▼
▲* '''[[Variable (
▲Input is given through two Atari keypad controllers, which came with special overlays to show how to type the different commands and letters.<ref>[https://atariage.com/controller_page.html?ControllerID=4&SystemID=2600 Controllers - Atari Keypad], {{Webarchive|url=https://web.archive.org/web/20150615042830/https://atariage.com/controller_page.html?ControllerID=4&SystemID=2600 |date=15 June 2015 }} Atari KeypadSystem: Atari 2600, Model Number: CX50, ''Sold in pairs, functionally identical to the Kid's Controller and the Video Touch Pad. Included overlays with commands, meant to be used with Basic Programming.''</ref> Programs
===Language features===
VCS BASIC supports the following keywords:<ref>{{cite book|title=BASIC Programming: Atari Game Program Instructions|date=1979|publisher=Atari, Inc.|___location=Sunnyvale, CA}}</ref>
* Statements: <code>Print</code>
* Structure: <code>Goto</code>, <code>If-Then-Else</code>
* Graphics: <code>Clear</code>
* Functions: <code>Hit</code>, <code>Key</code>
* Math: <code>+ - × ÷ Mod</code>
* Relational operators: <code>< > =</code>
Unlike most BASIC implementations of the time:
* VCS BASIC uses ← instead of = for assignment; e.g., <code>A←A+1</code>.
* Statements can be strung together on a line without a delimiter; e.g., <code>Note←APrintA</code>.
* An <code>If</code> statement can be used as a function, returning a value: <code>{{codett|2=cbmbas|Ver1←Ver1+IfVer1}}[[Modulo operation|Mod]]2{{codett|2=cbmbas|Then8}}{{codett|2=monkey|Else}}92</code>
* <code>If</code> statements can take an <code>Else</code> clause.
Special variable names:
* <code>Note</code> sounds a musical note, assigned numbers from 0 to 7
** Numbers assigned to <code>Note</code> are implicitly assigned modulus 8, thus 8 becomes 0, 9 becomes 1, etc.
* <code>Hor1</code>, <code>Hor2</code> - the horizontal coordinate of one of two squares
* <code>Ver1</code>, <code>Ver2</code> - the vertical coordinate of one of two squares
The language supports 26 unsigned integer variables A to Z. VCS BASIC supports integers from 0 to 99. Math operations wrap, so 99+1 becomes 0, 99+2 becomes 1, etc.
====Sample code====
The following example of a ''[[Pong]]'' game is provided.
{{pre|
1 Hor2←2+Key
2 {{codett|2=cbmbas|IfVer1>90ThenVer1←88}}
3 {{codett|2=cbmbas|IfHit}}{{codett|2=cbmbas|ThenVer1←9}}
4 {{codett|2=cbmbas|Ver1←Ver1+IfVer1}}[[Modulo operation|Mod]]2{{codett|2=cbmbas|Then8}}{{codett|2=monkey|Else}}92
5 Hor1←Hor1+7
6 {{codett|2=cbmbas|Goto1}}
}}
==See also==
{{Portal|Video games}}
* [[CompuMate|Spectravideo CompuMate]] Basic Keyboard Enhancer - kk 2600 cartridge▼
*[[List of Atari 2600 games]]
* [[Family BASIC]]
==References==
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==External links==
* {{
▲*{{wayback|date=20040123023347|url=http://www.mindspring.com/~sidartha/Basic%20and%20Compumate%20Programming.htm|title=Compumate FAQ:BASIC PROGRAMME EXAMPLES FOR ATARI 2600 (BASIC PROGRAMMING & CompuMate). AUTHOR: Graham.J.Percy, Version 1.0, 25th September, 1998.}}
{{BASIC}}
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[[Category:Atari
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[[Category:Discontinued BASICs]]
[[Category:Video game development software]]
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