!!!OSS Basic A+
Copyright (C) 1981 OSS, Inc.

[Atari BASIC] was originally written by a 3rd party company, Shepardson Microsystems. An early version was delivered in late 1978 for demonstration purposes so Atari could show it at the CES in January 1979. To the programmer's surprise, they learned that Atari started burning this version to ROM cartridges as the final product. This was in spite of a number of bugs having been found and corrected in the meantime.

Shortly after the release of Atari BASIC, the owner of Shepardson decided to dissolve the company. The Atari staff formed their own company, Optimized Systems Software (OSS), and purchased the licenses to the Atari products. Basic A+ was one of OSS's first products, consisting largely of the bug-fixed versions of Atari BASIC along with a few expansions. Among the notable additions were PRINT USING (for formatted output), trace and debug enhancements, and direct DOS commands. 

Too large to fit on a 8k ROM, the product was sold on disk only. Because BASIC A+ had to be purchased, programs developed using its extended features could not be shared with people who did not own the interpreter. A+ was never particularly popular, and soon superseded by the greatly improved [Basic XL].

* [OSS BASIC A+ in Wikipedia|https://en.wikipedia.org/wiki/BASIC_A%2B]\\

* [OSS_BASIC_A_Plus_3.1_Manual-May_1981.pdf] ; size: 1.5 MB
* [OSS_BASIC_A_Plus_3.1_Manual-May_1981-2.pdf] ; size: 13.9 MB
* [OSS_BASIC_A_Plus_Demo_Disk.pdf] ; size: 770 KB
* [OSS_BASIC_A_Plus_all_versions_with_DOS_XL_2.30p_Color.atr] ; 3.00, 3.04 and 3.05 versions of BASIC A+ on a single diskette
* [OSS_BASIC_A_Plus_3.00_to_3.04.atr] ; patch program in BASIC to update BASIC A+ version 3.00 to 3.04.
* [OSS_Basic_A_Plus_Demo_Disk.atr] ; demo diskette for BASIC A+ without DOS
* [OSS_BASIC_A_Plus_version_3.05_with_MS-DOS.atr] ; latest version with rare to find MS-DOS
* [OSS_BASIC_A_Plus_3.03.atr]
* [OSS_BASIC_A_Plus_3.00.xex]
* [OSS_BASIC_A_Plus_3.04.xex]
* [OSS_BASIC_A_Plus_3.05.xex]
[{Image src='3.00.jpg' width=452 height=107 }]
OSS Basic A+ version 3.00\\
[{Image src='3.04.jpg' width=442 height=105 }]
OSS Basic A+ version 3.04\\
[{Image src='3.05.jpg' width=448 height=102 }]
OSS Basic A+ version 3.05\\
* [Review for OSS BASIC A+ in ANTIC VOL. 2, NO. 2, MAY 1983|http://www.atarimagazines.com/v2n2/productreviews.html]