Random Apple Memory

Adam Banks remembers the Mac OS that dominated the 1990s

System 7, the Mac OS that dominated the 1990s.

Released in May 1991, System 7 was one of the biggest ever updates to the Macintosh operating system. Codenamed “Big Bang,” it inspired TV adverts touting the Mac as “the world’s easiest and most advanced personal computer.”

It was System 7 that introduced familiar features like full multitasking, file and folder aliases, help bubbles, AppleScript, and TrueType outline fonts. And for the first time the Macintosh user interface showed a touch of color.

Under the hood, some big innovations occurred in networking, helping to make it simple enough to implement in small offices and even homes; files and folders could easily be shared between Macs and even with Windows PCs. Another major advance was making all applications “32‑bit clean,” enabling them to address more than eight megabytes of memory. As a consequence, however, System 7 shipped with a compatibility checker that warned users about existing software that wouldn’t work after upgrading, or could even prevent the Mac starting up.

This and the new operating system’s outrageous requirements – it took up over a megabyte of memory, and made a hard disk obligatory – caused controversy, but System 7 was rapidly adopted and proved robust enough to carry Apple through the next six years, smoothing the transition to PowerPC processors. It was a success for Apple’s near-term “blue” team, known as the Blue Meanies after the characters in the Beatles’ “Yellow Submarine”; the long‑term "pink" team, meanwhile, fell into the OS strategy death spiral that would end in the 1997 purchase of NeXT.