GS/OS is an

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

developed by

Apple Computer Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Co ...

for its Apple IIGS

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

. It provides facilities for accessing the file system, controlling input/output devices, loading and running program files, and a system allowing programs to handle

interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...

s and signals. It uses

ProDOS ProDOS is the name of two similar operating systems for the Apple II of personal computer. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II computers, and was distributed ...

as its primary filing system. GS/OS is a component of Apple IIGS System Software versions 4.0 through 6.0.1, and was the first true 16-bit operating system for the IIGS.

Features

Speed optimization

The advantage of GS/OS over its predecessor, the ProDOS 16 operating system, is that it was written entirely in 16-bit code for the 65816 processor used in the IIGS, rather than primarily in 8-bit

6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small ...

machine code that does not take advantage of the IIGS's unique features. This in turn allows GS/OS to offer vast speed optimizations (loading time, disk access, screen updates) compared with the previous OS, and provided room to incorporate many features of other Apple operating systems, including

Apple III The Apple III (styled as apple ///) is a business-oriented personal computer produced by Apple Computer and released in 1980. Running the Apple SOS operating system, it was intended as the successor to the Apple II; however, it was largely cons ...

Apple SOS The Sophisticated Operating System, or SOS (), is the primary operating system of the Apple III computer. SOS was developed by Apple Computer and released in October 1980. In 1985, Steve Wozniak, while critical of the Apple III's hardware ...

, the Macintosh System 5, as well as concepts and features that would later appear in future Macintosh System Software releases (e.g. proportional scrollbars, thermometer progress bars).

New features and enhancements

In addition to continued enhancements to the IIGS Finder and loadable fonts, GS/OS offered plug-in device drivers (modem, printer, etc.), a thermometer progress display, AppleShare support, File System Translators for accessing foreign file formats, disk caching and support for storage devices up to 4 Gigabytes. It also extends the ProDOS file system to provide for

resource fork A resource fork is a fork of a file on Apple's classic Mac OS operating system that is used to store structured data. It is one of the two forks of a file, along with the data fork, which stores data that the operating system treats as unstruct ...

s on files similar to those used on the

Apple Macintosh Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup inclu ...

, which allows for programs to be written in a more flexible way. The newly included Apple ''Advanced Disk Utilities'' and ''Apple IIGS Installer'' helped facilitate partitioning, formatting and installing software and drivers with visual ease. A command-line development environment called APW (Apple Programmer's Workshop) is available; much like the

Macintosh Programmer's Workshop Macintosh Programmer's Workshop (MPW) is a software development environment for the Classic Mac OS operating system, written by Apple Computer. For Macintosh developers, it was one of the primary tools for building applications for System 7.x an ...

File System Translators

GS/OS includes a facility known as file system translators (FSTs) which allows it to support multiple on-disk file systems in a manner transparent to application programs and to the user, a feature not found in ProDOS or most other microcomputer operating systems at the time. While GS/OS natively uses the ProDOS file system (from which it must be booted), it also fully supports

HFS HFS may refer to: Businesses and organisations * Croatian Film Association () * Hellenic Fire Service, Greece * Hospitality Franchise Systems, US Computing * Hierarchical file system, a system for organizing directories and files * Hierarchica ...

used by

Mac OS Mac operating systems were developed by Apple Inc. in a succession of two major series. In 1984, Apple debuted the operating system that is now known as the classic Mac OS with its release of the original Macintosh System Software. The system ...

. Other file system translators include those for the

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

FAT file system, High Sierra/ISO 9660, Apple DOS 3.3, and Apple Pascal, albeit read-only (full read/write support had been planned but was never completed).

Releases

Source:

ProDOS 16 (GS/OS predecessor)

*1986 – System 1.0 (ProDOS 16 v1.0), System 1.1 (ProDOS 16 v1.1) *1987 – System 2.0 (ProDOS 16 v1.2), System 3.1 (ProDOS 16 v1.3) *1988 – System 3.2 (ProDOS 16 v1.6)

GS/OS

*1988 – System 4.0 (GS/OS v2.0) *1989 – System 5.0 (GS/OS v3.0), System 5.0.1 (GS/OS v3.0), System 5.0.2 (GS/OS v3.0) *1990 – System 5.0.3 (GS/OS v3.03) *1991 – System 5.0.4 (GS/OS v3.03) *1992 – System 6.0 (GS/OS v4.01) *1993 – System 6.0.1 (GS/OS v4.02)

Unofficial versions

*2015 – System 6.0.2 (GS/OS v4.02), System 6.0.3 (GS/OS v4.02) *2017 – System 6.0.4 (GS/OS v4.02)

References

External links

Apple IIgs GS/OS 6.0.1 Screenshots and details

GS/OS at the Apple II History Museum

A2Central.com
– Apple II news and downloads {{DEFAULTSORT:GS OS Apple II software Apple Inc. operating systems Disk operating systems Discontinued operating systems Window-based operating systems