System 6

MacroMaker

A new utility called MacroMaker was included with System 6. When enabled, it allowed users to record mouse and keyboard input as "macros." MacroMaker had a unique user interface, which aimed to look and act like a tape recorder. MacroMaker was criticized for its lack of features when compared to Microsoft's AutoMac III, which was already available commercially. As MacroMaker only recorded the locations of mouse-clicks inside windows and not what was being clicked or exactly when, users soon found that it could not be used to automate more sophisticated programs. The pre-recorded clicks would miss buttons if they had moved or failed to appear upon playback. In addition, MacroMaker had limitations wherein it recorded the start and end locations of mouse movements but not the precise path of the movements, and its macros did not handle situations that required the macro to wait for a period of time before or after an action. MacroMaker was not compatible with System 7, which marked the introduction of AppleScript as an alternative.

Multitasking

Cooperative multitasking made its Macintosh debut in March 1985 with a program called Switcher by Andy Hertzfeld, which allowed the user to launch multiple applications and switch between them. Many programs and features did not function correctly with Switcher. Also, Switcher did not display windows of other applications beside the selected one. It was not included with the operating system, but was available from Apple for purchase separately. Both System 5 and System 6 had a feature called MultiFinder instead, which was much more mature and widely used in System 6. MultiFinder could be enabled or disabled, with a reboot. If disabled, the Finder would quit when the user launched another application, thus freeing RAM for it. If enabled, the system behaved as in the nowadays familiar multitasking tradition, with the desktop and windows of other applications in the screen's background.

Hardware support

System 6 included support for the Apple ImageWriter LQ and other PostScript laser printers. New software drivers allowed the ImageWriter LQ to be used on AppleTalk local area networks and supports use of tabloid, or B, size paper (11 in × 17 in (280 mm × 430 mm)). System 6 also included Color QuickDraw, a piece of system software used to accelerate the drawing of color screen images on the Macintosh II. It was licensed to Apple and Radius Inc by its programmer, Andy Hertzfeld.

Limitations

System 6's Apple menu cannot be used to launch applications. The current application icon in the upper right-hand corner of the menu bar cycles between open applications; it is not a menu. System 6 supports 24 bits of addressable random access memory (RAM), which allowed a maximum of 8 megabytes of RAM with no provision for virtual memory. These limitations were fixed in System 7. The version of the HFS used by System 6 also has a hard drive capacity limit; it supports up to 2 gigabytes (GBs) and 65,536 files on a drive. This limitation was not increased until System 7.5 which first increased the limit to 4 GB.

The Trash (or "Wastebasket" in the British version) empties when the Finder terminates. If MultiFinder is not running, this occurs as soon as an application launches. Icons on the desktop in System 6 are not organized into a single folder, as in later operating systems. Instead, the system records whether each file is on the desktop or not. 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, mostly unchanged since 1984. The lack of aliases, shortcuts to files, was another limitation of file management on System 6. Custom file and folder icons are also not supported. These problems 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. Desk Accessories cannot be installed or removed within the Finder; this requires the Font/DA Mover utility. System 7 also fixed this. Control panels, however, are contained in separate files.

Few methods exist for interface personalization. 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 all black and white. However, many "INIT" extension files existed to add color and customization. System 7 later allowed the user to change the color and various other aspects of the user interface. By 1989, the System 6 user interface was in need of a change. In comparison to the NeXTSTEP operating system of the time, System 6 did not make use of sound, and its user interface presented several limitations in terms of file management and the way windows were displayed.

Reception

The initial releases of System 6 were unstable; many third party software developers did not receive copies before its release, resulting in widespread compatibility problems. At first, many common software programs such as Microsoft Excel, Microsoft Works 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 files. Apple announced that 66 bugs were fixed when the 6.0.1 update was released in September 1988. However, a major bug involving text spacing of screen fonts was found in 6.0.1 after distribution began. This led to the quick release of 6.0.2, which solved this problem. Some customers waited longer until moving to System 6 because of the poor reputation already gained.

Compatibility

System 6 was officially supported by Apple for many different machines, some of which were shipped with System 6. It may be that some Apple computers for which System 6 was not officially supported may nevertheless be able to run it, perhaps with limitations.