Apple System 5

System 5

( Predecessor: System 4 (1987) | Successor: System 6) )

Apple System 5 is the fifth major version of the then-to-be classic MacOS series of operating systems produced by Apple Inc.

Towards the end of 1987, Apple introduced a package titled "Apple Macintosh System Software Update 5.0". For the first time, the Macintosh operating system was offered as a distinct retail product that included four 800K disks and three manuals, at a cost of US$49. The software itself was still freely available through user groups and bulletin board services. While the product box presented this update to the operating system as "version 5.0", this number does not appear in the software itself. Three of the four disks (System Tools 1, System Tools 2 and Utilities 1) are all bootable, and the user can boot off of whichever floppy contain the tools the user needs. For instance, System Tools 2 is the only disk with printer drivers, and Utilities 1 is the only disk with Disk First Aid and Apple HD SC Setup. Because the disks are named System Tools, users and the press commonly referred to this version as "System Tools 5.0".

The primary new feature of System 5 is MultiFinder, an extension which lets the system run several programs at once. The system uses a cooperative multitasking model, meaning that time is given to the background applications only when the foreground application yields control. A change in system functions that applications were already calling to handle events make many existing applications share time automatically, as well as being allowed to perform tasks in the background. Users can also choose not to use MultiFinder, thereby using a single application at a time. In 1990 InfoWorld tested four multitasking options for PC and Mac, viewing MultiFinder positively overall, but noting that its presence halved the speed of file transfer and printing compared to the single-tasking System 6 without MultiFinder. System Software