Editing Turbo-BASIC XL (section)

{{Distinguish|Turbo Basic}}
{{More citations needed|date=April 2020}}
{{Infobox software
| name = Turbo-BASIC XL
| logo = 
| logo alt = 
| logo caption = 
| screenshot = Turbo-BASIC XL-1.5.png
| screenshot alt = Version 1.5 startup screen
| caption = Version 1.5 startup screen
| collapsible = <!-- Any text here will collapse the screenshot -->
| author = [[Frank Ostrowski]]
| developer = 
| released = {{Start date and age|1985|12|}}
| discontinued = <!-- Set to yes if software is discontinued, otherwise omit -->
| ver layout = <!-- simple (default) or stacked -->
| latest release version =
| latest release date = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| latest preview version =
| latest preview date = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} -->
| programming language = 6502 assembly
| operating system = 
| platform =  [[Atari 8-bit]]
| size = 
| language = 
| language count = <!-- Number only -->
| language footnote = 
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| website = <!-- {{URL|example.org}} -->
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}}

'''Turbo-BASIC XL''' is an enhanced version of the [[BASIC]] programming language for [[Atari 8-bit computers]]. It is a compatible superset of the [[Atari BASIC]] that shipped with the computers. Turbo-Basic XL was developed by [[Frank Ostrowski]] and published in the December 1985 issue of [[German language|German]] [[computer magazine]] ''Happy Computer''.<!-- (C) ''[[Markt und Technik Verlag]]'' -- publishers of ''Happy Computer''? --Wernher --> A version for the 400/800 models was released shortly after as '''Frost Basic 1.4'''. Several modified versions working with different DOS systems have been released by other authors.

Turbo-Basic XL greatly improves execution over Atari BASIC. An Atari BASIC program loaded into Turbo-BASIC, with no changes made, would generally run about three times as fast. A Turbo-Basic XL [[compiler]] created binary [[executable]]s, further speeding up program performance to about ten times faster than Atari BASIC. Turbo-Basic XL also includes an expanded editor, support for named procedures, {{code|WHILE...ENDWHILE}} and similar block constructs, and added access to the underlying hardware, which, among other things, allowed operation of attached [[floppy drive]]s without exiting to [[Atari DOS|DOS]].

Ostrowski soon got a job with ''GFA Systemtechnik GmbH'' (at the time known as ''Integral Hydraulik'') where he adapted Turbo-Basic XL into [[GFA BASIC]] for the [[Atari ST]], which became one of the more popular BASICs on that platform.