System 6 (or System Software 6) is the sixth major release of the

classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and end ...

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 ...

for

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 ...

computers, made 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 ...

. It was released in 1988. It is a

monolithic A monolith is a monument or natural feature consisting of a single massive stone or rock. Monolith or monolithic may also refer to: Architecture * Monolithic architecture, a style of construction in which a building is carved, cast or excavated f ...

operating system, with

cooperative multitasking Cooperative multitasking, also known as non-preemptive multitasking, is a computer multitasking technique in which the operating system never initiates a context switch from a running Process (computing), process to another process. Instead, in o ...

based on an improved

MultiFinder MultiFinder is an extension for the Apple Macintosh's classic Mac OS, introduced on August 11, 1987 and included with System Software 5. It adds cooperative multitasking of several applications at once – a great improvement over the previo ...

. The boxed version cost , and it was included with all new Macintosh computers until 1991, when it was succeeded by

System 7 System 7 (later named Mac OS 7) is the seventh major release of the classic Mac OS operating system for Macintosh computers, made by Apple Computer. It was launched on May 13, 1991, to succeed System 6 with virtual memory, personal file shari ...

Overview

MacroMaker

The MacroMaker utility was introduced in System 6. It records mouse and keyboard input as macros, and has a unique user interface intended to look and act like a

tape recorder An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present ...

. MacroMaker was criticized for its lack of features when compared to

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

's AutoMac III, which was already available commercially. As MacroMaker records only the locations of mouse-clicks inside windows and not what is being clicked on or exactly when, it can not be used to automate actions in more sophisticated programs. The pre-recorded clicks miss buttons if the buttons had moved since the recording, or if they failed to appear upon playback. It records the start and end locations of mouse movements, but does not track the precise path of a movement or support pauses. MacroMaker is not compatible with

, in which it is succeeded by

AppleScript AppleScript is a scripting language created by Apple Inc. that facilitates automated control of Mac applications. First introduced in System 7, it is currently included in macOS in a package of automation tools. The term ''AppleScript'' may ...

Multitasking

Macintosh gained cooperative multitasking in March 1985 with

Andy Hertzfeld Andrew Jay Hertzfeld (born April 6, 1953) is an American software engineer who was a member of Apple Computer's original Macintosh development team during the 1980s. After buying an Apple II in January 1978, he went to work for Apple Computer fr ...

's Switcher, which can switch between multiple full-screen applications. It was not integrated, and was only sold separately by Apple. Not many programs and features function correctly with Switcher, and it does not share the screen between applications simultaneously. Systems 5 and 6 have

instead, which is much more mature and widely used in System 6. With MultiFinder, the Finder does not quit to free resources, and the system behaves as in the still-familiar multitasking fashion, with the desktop and other applications' windows in the background.

Hardware support

System 6 includes support for the Apple

ImageWriter LQ The ImageWriter is a product line of dot matrix printers formerly manufactured by Apple Computer, Inc., and designed then to be compatible with their entire line of computers. There were three different models introduced over time, which wer ...

and

PostScript PostScript (PS) is a page description language and dynamically typed, stack-based programming language. It is most commonly used in the electronic publishing and desktop publishing realm, but as a Turing complete programming language, it c ...

laser printers Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to d ...

. New

software driver In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

s allow the ImageWriter LQ to be used on

AppleTalk AppleTalk is a discontinued proprietary suite of networking protocols developed by Apple Computer for their Macintosh computers. AppleTalk includes a number of features that allow local area networks to be connected with no prior setup or the ...

local area networks and supports the use of tabloid or B-size paper (). System 6 includes QuickerGraf (originally QuickerDraw), system software used to accelerate the drawing of color images on the

Macintosh II The Macintosh II is a personal computer designed, manufactured, and sold by Apple Computer from March 1987 to January 1990. Based on the Motorola 68020 32-bit CPU, it is the first Macintosh supporting color graphics. When introduced, a basic ...

. It was licensed to Apple and

Radius Inc. Radius Inc. was an American computer hardware firm founded in May 1986 by Burrell Smith, Mike Boich, Matt Carter, Alain Rossmann and joined by other members of the original Macintosh team like Andy Hertzfeld. The company specialized in Macint ...

by its programmer, Andy Hertzfeld.

Limitations

In comparison to the

NeXTSTEP NeXTSTEP is a discontinued object-oriented, multitasking operating system based on the Mach kernel and the UNIX-derived BSD. It was developed by NeXT, founded by Steve Jobs, in the late 1980s and early 1990s and was initially used for its ...

operating system of the time, System 6 does not make much use of sound, and its user interface is limited in file management and window displays. System 6's Apple menu cannot be used to launch applications. The icon in the upper right-hand corner of the

menu bar A menu bar is a graphical control element which contains Drop-down list, drop-down menus. The menu bar's purpose is to supply a common housing for window- or Application software, application-specific menus which provide access to such function ...

simply shows the open application and is not a menu. System 6 supports 24

bit The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...

s of addressable

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

(random-access memory), which allows for a maximum of 8

megabyte The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes ...

s of RAM, with no provision for

virtual memory In computing, virtual memory, or virtual storage, is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a ver ...

. These limitations were removed in System 7. System 6's version of the

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 ...

file system also has a

volume Volume is a measure of regions in three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch) ...

size limit; it supports up to 2

gigabyte The gigabyte () is a multiple of the unit byte for digital information. The SI prefix, prefix ''giga-, giga'' means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte i ...

s (GB) and 65,536 files on any one volume. System 7.5 increased this limit to 4 GB, and 7.5.2 increased it further to 2 TB on certain machines, specifically PCI-based Macintosh models. The Trash (known as the "Wastebasket" in the British-English version) empties when the Finder terminates. Icons on the Desktop in System 6 are not organized into a single folder, as in later operating systems. Instead, the system records if a file is on the Desktop. This is inefficient and confusing, as the user cannot browse to the Desktop in applications besides the Finder, even within the standard ''Open'' and ''Save As'' dialog boxes. Furthermore, these dialogs are primitive, and were mostly unchanged since 1984. The lack of aliases, shortcuts to files, is another limitation of file management on System 6, and custom file and folder icons are not supported. These issues were all remedied in System 7. A maximum of 15 desk accessories may be installed at one time, including the Chooser, Scrapbook, and Control Panel. System 6 uses the Control Panel desk accessory to access all the installed control panels, which imposes severe user-interface limitations. In System 7, Control Panels are contained in separately openable panels, and are held in a central folder for better organization. Desk Accessories cannot be installed or removed within the Finder; this requires the Font/DA Mover utility. System 7 also fixed this. The interface is not very customizable. The Finder allows each icon to be assigned a color, but the desktop background is limited to an 8x8-pixel color tiled pattern (color patterns were introduced in System 5), and standard window frames are black-and-white. However, many "

INIT In Unix-based computer operating systems, init (short for ''initialization'') is the first process started during booting of the operating system. Init is a daemon process that continues running until the system is shut down. It is the direc ...

" extension files exist to add color and customization. System 7 allows the user to change the color of window frames and various other aspects of the user interface. By 1989, the System 6 user interface was in need of a change.

Reception

Initial releases of System 6 are unstable; Don Crabb of ''

BYTE The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

'' described 6.0 as "buggy and unreliable". Many third-party developers did not receive advance copies, resulting in widespread compatibility issues. The contemporary versions of many common programs such as

Microsoft Excel Microsoft Excel is a spreadsheet editor developed by Microsoft for Microsoft Windows, Windows, macOS, Android (operating system), Android, iOS and iPadOS. It features calculation or computation capabilities, graphing tools, pivot tables, and a ...

Microsoft Works Microsoft Works is a discontinued office suite, productivity software suite developed by Microsoft and sold from 1987 to 2009. Its core functionality includes a word processor, a spreadsheet and a database management system. Later versions have a ...

and 4th Dimension were not fully compatible with System 6. There were also software bugs in the Color Manager, Script Manager, and Sound Manager

extension Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (proof theory) * Extension (predicate logic), the set of tuples of values that ...

files. Apple announced that 66 bugs were fixed with version 6.0.1 update, in September 1988. However, a major bug involving the text-spacing of screen fonts was found, and was fixed in version 6.0.2, which Crabb described as "a ''huge'' improvement" over 6.0. Some customers waited longer until moving to System 6 because of its poor reputation.

Compatibility

System 6 was officially supported by Apple for many different machines, some of which shipped with it. Some unsupported Macintosh computers can run it with limitations.

Version history

Timeline

References

External links

Macintosh: System Software Version History
at

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

{{Good article 1988 software Classic Mac OS Proprietary operating systems Pascal (programming language) software