History of the classic Macintosh OS

History of the classic Macintosh OS

Today we’re going to explore the history of the classic Macintosh operating system. MacOS is the modern operating system that powers every Macintosh computer, from the Mac mini to the iMac Pro. But the Classic Macintosh operating systems, Mac OS 9 and lower, is what we’ll be focusing on in this article.

May 21 ·10min read

Photo by Julian Hochgesang on Unsplash

T oday we’re going to explore the history of the classic Macintosh operating system. Now MacOS is the modern operating system that powers every Macintosh computer, from the Mac mini to the iMac Pro. But the Classic Macintosh operating systems, Mac OS 9 and lower, is what we’ll be focusing on in this article.

As part of Apple’s goal of creating a computer with appliance-like simplicity, there was no distinction made between the operating system software and the hardware it ran on. Because of this, early versions of the operating system didn’t have specific names. So version numbers of the operating system are based on the Finder and system file versions.

Macintosh System Software 1 was introduced alongside the original Macintosh 128K to much applause by Steve Jobs on January 24th, 1984 . In fact, the round of applause that followed its introduction was one of the longest in recorded history. This initial iteration of the Mac operating system was simply called Macintosh System Software. Although it would later be referred to as Macintosh System Software 1 as newer versions were released.

Macintosh System Software 1

Many people have mistakenly claimed that this operating system was the first to feature a cursor with a graphical user interface. But that title belonged to the Apple LISA. System 1 introduced many features that would remain in later iterations even to this day.

Some of those included the Finder, a file manager responsible for launching applications and the overall user management of files, disks, and network volumes. The menu bar was also a new and revolutionary part of the operating system. Similar to the one found on the Lisa OS, the Macintosh menu bar had 5 basic headers when on the desktop: the Apple menu, File, Edit, View, and Special.

Although the menu bar options would change depending on the application in use. System 1 also featured seven desk accessories like the Alarm Clock, which could be used just like a real alarm. The computer would beep and the menu bar would flash when the alarm’s set time was reached. It could also be used as an easier way to set the time and date on the computer.

Alarm Clock

The second was a basic 10 button Calculator capable of addition, subtraction, multiplication.


Third, a Control Panel could be used to adjust some of the computers settings like volume, double click speed, mouse sensitivity, and desktop background. On the Macintosh 128K, Macintosh 512K, and the Macintosh Plus, the screen brightness was controlled by a mechanical adjustment wheel beneath the screen.

Control Panel

What made the original control panel unique from later versions was the absence of any text. Apple did this to demonstrate the graphical user interface.

The fourth was Key Caps, which was used to show the layout of the original Macintosh keyboard. Although it didn’t include keyboard shortcuts that could be achieved with modifier keys like shift, option, and command.


The fifth was a Note Pad, that would save typed text onto the floppy disk, multiple note pages could also be written.

Sixth was a basic 15 piece slide Puzzle, similar to the picture puzzles found in later versions of the Mac OS.

And finally, Scrapbook which was like a cut, copy, and paste library. You could store text selections and photos to transfer to other applications. Applications available for purchase on the Macintosh included MacPaint, MacWrite, MacProject, MacTerminal and Microsoft Word.


A difference between desktop accessories and applications is that multiple desktop accessories could be run at once but only one application could run at a time. This is due to the limited amount of RAM and the lack of an internal hard disk in the original Macintosh. Also, items in the Trash were permanently deleted when the computer was shut down or a new application was loaded.

System 1’s total size is about 216 KB and contained six files: System (which included the desk accessories), Finder, Clipboard, an Imagewriter printer driver, Scrapbook, and Note Pad. A separate floppy disk included “A Guided Tour of Macintosh”, which contained tutorial demonstrations of the Macintosh system as well as training programs for learning to use the mouse and the Finder. Also included was a 33-minute audio cassette designed to run alongside the demonstrations as a compliment to the floppy disk.

Systems 2 to 4 added helpful features to the Macintosh but none contained anything monumental. System 2 added support for AppleTalk which allowed a local network of Macintosh computers to be connected without the need for a centralized router or server. System 2 also introduced support for the LaserWriter and added a Hierarchical File System which allowed file directories to be searched quickly regardless of size.

File System

System 3.0 was introduced with the Macintosh Plus, officially implementing HFS, 800K startup drives, support for several new technologies including SCSI and AppleShare, and Trash “bulging” where the Trash icon would appear bulged when files are added. System 4.0 was released with the Macintosh SE and System 4.1 first shipped with the Macintosh II — these new machines required software support for the first expansion slots, Apple Desktop Bus, internal hard drives, external color displays and the first Motorola processor.

Macintosh Plus, Macintosh II and Macintosh SE

As I said before, these OS releases can only run one application at a time, except for desk accessories, though special application shells such as Multi-Mac or Switcher could work around this. 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 $49 USD. While the product box presented this update to the operating system as “version 5.0”, this number did not appear in the software itself.

Macintosh System Software Update 5.0

Three of the four disks (System Tools 1, System Tools 2 and Utilities 1) were all bootable, and the user could boot off of whichever floppy contained the tools the user needed. For example, System Tools 2 was the only disk with printer drivers, and Utilities 1 was the only disk with Disk First Aid and Apple HD Setup. Because the disks were named System Tools, users and the press commonly referred to this version as System Tools 5.0. The main feature of System 5 was MultiFinder, an extension which let the system run several programs at once.

But users could choose to disable MultiFinder and stick with running one application at a time. Also included with System 5 for the first time was Installer, a tool that could be used to update a previous System folder to a new version. Because Installer typically targeted a floppy disk, the user needed to indicate which Macintosh the floppy would be used on, so that the correct control panels could be included.


Installer could also be used to update printer drivers. System Software 5 was available for a very short time and only in some countries, including the United States, Canada and some European countries. System Software 6 is a consolidation release of the Macintosh system software, producing a complete, stable, and long-lasting operating system. One of the few features introduced in System 6 was a new utility called MacroMaker.

System Software 6

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. It was a great concept but left much to be desired. It was criticized for its lack of features when compared to Microsoft’s AutoMac III, which was already available commercially.

Microsoft’s AutoMac III

On May 13, 1991, System 7 was released. It was a major upgrade over System 6, adding a user interface overhaul, new applications, stability improvements and many new features. The System 7 era saw numerous changes in the Macintosh platform including a proliferation of Macintosh models.

System 7

The 68k to Power Macintosh transition as well as the rise of Microsoft Windows. These changes, in addition to the internet becoming popular, contributed to rising computer usage and networking. One of the most significant features of System 7 is virtual memory support, which previously had only been available as a third-party add-on.

Accompanying this was a move to 32-bit memory, necessary for the ever-increasing amounts of RAM available. To ease the transition, the “Memory” control panel contained a switch to disable the 32-bit feature, allowing for compatibility with older applications. Other notable System 7 additions were built-in cooperative multitasking and the ability to create aliases, similar to shortcuts that were introduced in later versions of Microsoft Windows.

System extensions were enhanced by being moved to their own subfolder, and in System 7.5, Apple included the Extensions Manager. A previously third-party program which simplified the process of enabling and disabling extensions. The Apple menu, previously limited to desk accessories in System 6, was made more general-purpose: the user could now make frequently-used folders and applications — or anything else they desired — appear in the menu by placing aliases to them in an “Apple Menu Items” subfolder.

System 7 also introduced AppleScript, a scripting language for automating tasks; 32-bit QuickDraw, supporting so-called “true colour” imaging, previously available as a system extension; and TrueType, an outline font standard. The Trash under System 6 and earlier empties itself automatically when shutting down the computer or when launching an application, but in System 7, Trash became a special hidden folder allowing files to remain in it across reboots until the user deliberately chose the “Empty Trash” command.

Mac OS 8 was released on July 26, 1997 , shortly after Steve Jobs returned to the company. It was mainly released to keep the Mac OS moving forward during a difficult time for Apple. Initially planned as Mac OS 7.7, it was renumbered “8” to exploit a legal loophole and accomplish Job’s goal of terminating third-party manufacturers’ licenses to System 7 and shutting down the Macintosh clone market.

Mac OS 8

Mac OS 8 added a number of features from the abandoned Copland project, while leaving the underlying operating system unchanged. A multi-threaded Finder was included; so files could now be copied in the background. The GUI was changed in appearance to a new shaded greyscale look named Platinum, and the ability to change the appearance themes (also known as skins) was added with a new control panel (though Platinum was the only theme shipped).

Apple sold 1.2 million copies of Mac OS 8 in its first two weeks of availability and 3 million within six months. Because of Apple’s financial difficulties at the time, there was a large grassroots movement among Mac users to upgrade and “help save Apple”. Even some pirate groups refused to redistribute the OS. Mac OS 9, the last major revision of the classic Mac OS, was released on October 23, 1999.

Mac OS 9

It was a steady evolution from Mac OS 8 as early development releases of Mac OS 9 were numbered 8.7. Mac OS 9 added improved support for AirPort wireless networking and introduced an early implementation of multi-user support. Although it wasn’t a true multi-user operating system, Mac OS 9 did allow multiple desktop users to have their own data and system settings.

An improved Sherlock search engine added several new search plug-ins. Mac OS 9 also provided improved memory implementation and management. AppleScript was improved to allow TCP/IP and networking control.

Mac OS 9 also included an Apple Software Update feature to easily find and install updates for the operating system and hardware. Other new features included on-the-fly file encryption software with code signing and Keychain technologies, Remote Networking and File Server packages, and a much improved list of USB drivers. Mac OS 9 also added some transitional technologies to help application developers adopt some Mac OS X features before the introduction of the new OS to the public to help ease the transition.

These included new APIs for the file system and bundling of the Carbon library that apps could link against instead of the traditional API libraries — apps that were adapted to do this could be ran natively on Mac OS X as well. The final update to the classic Macintosh Operating System was version 9.2.2, released on December 5, 2001.