Editing BASIC09 (section)

{{Infobox programming language
| name                       = BASIC09
| year                       = {{Start date and age|1980}}
| designer                   = [[Motorola]]
| developer                  = [[Microware]]
| latest release version     = 1.1.0
| latest release date        = {{Start date and age|2003|01|05}}
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'''BASIC09''' is a structured [[BASIC programming language]] dialect developed by [[Microware]] on behalf of [[Motorola]] for the then-new [[Motorola 6809]] [[central processing unit|CPU]] and released in February 1980.{{sfn|Manual|1984|p=1.2}} It is primarily used with the [[OS-9]] [[operating system]], released in 1979. Microware also released a version for OS-9/68k on the [[Motorola 68000|68000]] as '''Microware BASIC'''.<ref>{{cite web|url=http://geneslinuxbox.net:6309/gene/nitros9/3rdparty/packages/basic09/ReadMe.b09 |title=BASIC09 |website=Geneslinuxbox.net:6309 |access-date=2016-11-27}}</ref>

In contrast to typical BASICs of the era, BASIC09 includes a multi-pass [[compiler]] that produces compact [[bytecode]] known as '''I-code'''. I-code replaces a number of data structures found in other BASICs with direct pointers to code and values, speeding performance. Users can further compile code using the <code>PACK</code> command, at which point it can be called directly by OS-9 and operated as native code. In the case of PACKed code, a cut-down version of the BASIC09 [[runtime system]] is used, '''Runb''', further improving [[memory footprint]] and load time.

The language includes a number of [[structured programming]] additions, including [[local variable]]s, the ability to ignore line numbers in favor of named routines, user-defined structures, and several distinct base data types including 16-bit and 8-bit (byte) integers, in addition to floating point and strings.