Optimized Systems Software
| Company type | Private |
|---|---|
| Industry | Software development |
| Predecessor | Shepardson Microsystems (rights acquired) |
| Founded | January 1, 1981 in Cupertino, California, United States |
| Founder | Bill Wilkinson, Mike Peters, Paul Laughton, Kathleen O'Brien |
| Defunct | 1988 |
| Fate | Merged with ICD |
| Successor | ICD |
| Headquarters | Cupertino , United States |
Area served | Primarily Atari 8-bit computers; also Apple II and Atari ST platforms |
Key people | Bill Wilkinson (director) |
| Products | OS A+, DOS XL, BASIC A+, BASIC XL, BASIC XE, EASMD, MAC/65, Action!, Personal Pascal, Personal Prolog |
Number of employees | 15 (1984) |
Optimized Systems Software (OSS) was a company focused on developing disk operating systems, programming languages with integrated development environments, and software applications mainly for Atari 8-bit computers. Established by Bill Wilkinson, Mike Peters, Paul Laughton, and Kathleen O'Brien—who had been instrumental in creating essential Atari software such as Atari DOS, Atari BASIC, and the Atari Assembler Editor—OSS significantly enhanced these original products. Their prominent releases included OS A+ and DOS XL (both derived from Atari DOS), BASIC A+, BASIC XL, and BASIC XE (evolutions of Atari BASIC), alongside assemblers like EASMD and MAC/65. The company also produced Action!, a compiled language inspired by ALGOL featuring a full-screen editor, and offered software for the Apple II platform.
OSS later ventured into the Atari ST arena with Personal Pascal and targeted the Mac environment through Personal Prolog, though their influence in these sectors remained modest. In 1988, OSS merged with ICD.
History
Formed in early 1981 in Cupertino, California by Wilkinson, Peters, Laughton, and O'Brien, OSS secured the rights to Atari BASIC, Atari DOS, and the Assembler Editor from Shepardson Microsystems, which had withdrawn from those markets. The company enhanced these products—renaming them OS/A+, BASIC A+, and EASMD—and maintained collaborative efforts with Atari, Inc. on improved software versions that often were never officially released.
OSS made its debut at the West Coast Computer Faire in March 1981. Their offerings rapidly earned acclaim among Atari developers, particularly the MAC/65 assembler, the Action! programming language, and BASIC XL. By 1984, under Wilkinson’s direction, the firm employed roughly 15 people.
In January 1988, OSS united with ICD—recognized for SpartaDOS and various Atari hardware expansions—strengthening their position in the market. Later in 1994, Fine Tooned Engineering acquired limited rights to ICD’s 8-bit software before eventually closing down.
OS/A+
The Atari DOS 2.0S system consisted of a memory-resident component responsible for disk file access and a disk-resident menu-driven utility for file management on the Atari 810 disk drive. Due to the menu system’s size, it could not remain memory-resident; users had to reload it after each program execution, which caused frustration.
- Versions OS/A+ 2.0 and 2.1 replaced Atari DOS and Apple II DOS with a disk-based command-line interface modeled after CP/M and later MS-DOS. This more compact command line stayed resident during application use, removing reload delays. Initially called CP/A at the West Coast Computer Faire, the name was altered following legal concerns from Digital Research, owners of CP/M.
- The release of OS/A+ 4.1 brought advanced features such as support for "long" filenames well before Microsoft’s VFAT implementation. However, disks formatted under OS/A+ 4.1 lacked backward compatibility with earlier versions, and its increased memory requirements limited compatibility with some programs. These drawbacks impeded widespread adoption despite its technical progress. OSS briefly reissued this version when they discontinued enhancements to DOS XL for double-sided disk functionality.
DOS XL
DOS XL was designed to succeed OS/A+ by offering compatibility with both single and double-density disk drives. It preserved the familiar OS/A+ command line interface and incorporated a menu-driven program. This operating system utilized the unused memory found in Atari XL/XE models and OSS supercartridges, while also supporting Indus GT Synchromesh disk drives. Due to limited market interest and Atari's development of a new DOS iteration, OSS halted development on DOS XL 4 and instead re-released OS/A+ 4.1.
BASIC
The team at Shepherdson Microsystems, responsible for Atari BASIC, developed three increasingly sophisticated BASIC interpreters under OSS.
BASIC A+
The original Atari BASIC fit within an 8K cartridge, with plans for a supplementary cartridge to expand its capabilities—though this expansion never materialized. Instead, OSS launched the disk-based BASIC A Plus (BASIC A+), which maintained compatibility with Atari BASIC while resolving bugs and introducing enhancements such as PRINT USING for formatted output, improved tracing and debugging tools, direct integration of DOS commands, and explicit support for graphics hardware including player/missile graphics. As a commercial product, programs utilizing BASIC A+'s advanced features required users to possess the interpreter to ensure compatibility.
BASIC XL
BASIC XL is a bank-switched cartridge iteration that superseded BASIC A+, correcting defects and adding new functionalities. The BASIC XL Toolkit supplements this with additional source code, illustrative examples, and a runtime package facilitating program distribution.
A notable advancement is its approach to handling line number references in GOTO/GOSUB statements and FOR...NEXT loops. Unlike Atari BASIC—which searches the entire program to resolve line numbers—BASIC XL employs the FAST command to replace fixed line targets with direct addresses, resulting in significant performance gains comparable to Microsoft BASIC. This optimization, however, disables the ability to continue execution after modifying code during runtime.
In 1984, Antic lauded BASIC XL as "the fastest and most powerful version of BASIC available for Atari computers," commending its "exceptional" documentation and recommending its inclusion as standard on Atari machines.
BASIC XE
BASIC XE builds upon BASIC XL by incorporating new functions alongside high-speed mathematical routines. It requires a minimum of 64KB RAM and operates exclusively on XL/XE hardware. While no dedicated runtime was issued for BASIC XE, the runtime designed for BASIC XL can be utilized with some limitations.
EASMD
EASMD (Edit/Assemble/Debug) represented OSS's initial editor/assembler solution, launched on disk in 1981. Derived from the Atari Assembler Editor, it was eventually superseded by MAC/65.
MAC/65
Introduced on disk in 1982 and later as a bank-switched "supercartridge" in 1983, MAC/65 is a 6502 assembler and editor featuring an integrated debugger known as DDT. It tokenizes source code with line numbers similarly to Atari BASIC but executes assembly tasks much faster. The MAC/65 Toolkit offers additional sample code and resources.
BUG/65
BUG/65 is a machine language debugger originally packaged with MAC/65. Its cartridge version included a standalone debugger named DDT. Eventually, BUG/65 was integrated into DOS XL.
Action!
Action! is a cartridge-based development environment featuring a language similar to ALGOL that compiles directly into highly optimized 6502 machine code. It integrates a full-screen editor with a compiler that operates without accessing disk storage, resulting in execution speeds over 100 times faster than Atari BASIC, while maintaining greater simplicity compared to assembly programming. Programs compiled with Action! depend on the cartridge because the standard library functions are stored there; nevertheless, the Action! Run-Time Package allows distribution of applications without requiring the cartridge.
The Action! Toolkit—initially named Programmer's Aid Disk (PAD)—provides extra code libraries and sample programs to assist developers working with Action!.
C/65
C/65 is a compiler crafted by LightSpeed Software that supports a limited subset of the C language. It generates assembly source code output, which must then be assembled into executable form using an assembler such as MAC/65.
Tiny C
tiny-c is an interpreter designed for a subset of the C programming language and was created by Tiny C Associates.
Personal Pascal
Released by OSS in 1987 and developed by J. Lohse, Personal Pascal is a single-pass compiler for Pascal targeting the Atari ST that produces machine code directly. It was accompanied by an extensive manual exceeding 500 pages.
The Writer's Tool
Published by OSS in 1984 and developed by Madison Micro, The Writer's Tool is a word processing program available on both cartridge and double-sided disk formats. Its release prompted OSS to discontinue their own word processor project.
SpeedRead+
SpeedRead+ serves as a speed reading tutor designed for use on Atari 8-bit and Apple II platforms.
Sales
According to Bill Wilkinson, OSS sold roughly 12,000 units of Basic XL prior to merging with ICD. Basic XL achieved sales approximately 2.5 to 3 times greater than those of Action!, while MAC/65 outsold Action! by about one and a half times. Conversely, Basic XE did not meet sales expectations. Personal Pascal recorded sales surpassing 10,000 copies.
References
- Notes
- Wilkinson, Bill (1983). The Atari BASIC Source Book. Compute! Books. .
- A User's Guide and Reference Manual for DOS XL 2.30, 1983
- OSS Newsletter - Spring 1984
- OSS Newsletter - October 1984
External links
- Dan's tribute to OSS — A site dedicated to OSS software for Atari 8-bit systems
- The Atari 400/800 and OSS
- Antic Vol. 4, No. 9 - Jan 1986 Review of Basic XE
- Articles with short description
- Optimized Systems Software
- Defunct software companies of the United States
- Atari 8-bit computers
- Software companies based in the San Francisco Bay Area
- Companies based in Cupertino, California
- American companies established in 1981
- Software companies established in 1981
- Software companies disestablished in 1988
- 1981 establishments in California
- 1988 disestablishments in California
- Defunct companies based in the San Francisco Bay Area
- 5
- Companies of the United States by year of establishment