The
"Classic" Mac OS[4] is a
graphical user interface-based
operating system developed by
Apple Inc. for its
Macintosh family of
personal computers from 1984 until 2001, the original member of the series of
Macintosh operating systems. The Macintosh platform, which was introduced in the classic Mac OS, is credited with having popularized the early
GUI concept.
[5]
Mac OS was preinstalled on every Macintosh computer that was made
during the era it was developed; it was also sold separately in retail
stores.
Apple released the
original Macintosh on January 24, 1984. Its
early system software was partially based on the
Lisa OS, previously released by Apple for the
Lisa computer in 1983; as part of an agreement allowing
Xerox to buy
shares in Apple at a favorable price, it also used concepts from the
Xerox PARC Alto computer, which former Apple CEO
Steve Jobs and other Macintosh team members had previewed.
[1] The operating system integral to the Macintosh was originally named
System Software, or simply "System", and referred to by its major revision starting with
System 6 and
System 7. Apple rebranded the system as
Mac OS in 1996, starting officially with version 7.6, due in part to its
Macintosh clone program.
[6] That program ended after the release of
Mac OS 8 in 1997.
[7] The last major release of the system was
Mac OS 9 in 1999.
[8]
Mac OS is characterized by its
monolithic system. From its
original release through System 4, it ran only one application at a time. Even so, it was noted for its ease of use. Mac OS gained
cooperative multitasking with System 5, which ran on the
Macintosh SE and
Macintosh II. It was criticized for its very limited
memory management, lack of
protected memory, no
access controls, and susceptibility to conflicts among
extensions that provide additional functionality such as networking or support for a particular device.
[9]
After a
four-year development effort spearheaded by
Steve Jobs' return to Apple in 1997, Apple replaced Mac OS with a new operating system in 2001 named
Mac OS X; the "X" represented the
tenth major revision of the Mac system software as well as its history as part of
NeXT and its relation to
Unix. Mac OS X was renamed "OS X" in 2012 and "
macOS" in 2016.
[10] The general interface design of the current macOS shares its legacy with the classic Mac OS, and there was some overlap of
application frameworks for compatibility, but the two systems have different origins and use deeply different architectures.
The
final updates to Mac OS 9
released in 2001 provided interoperability with Mac OS X. The name
"Classic" that now signifies the historical Mac OS as a whole is a
reference to the
Classic Environment, a
compatibility layer that helped ease the transition to Mac OS X.
[11]
Initial concept
The Macintosh project started in late 1978 with
Jef Raskin,
who envisioned an easy-to-use, low-cost computer for the average
consumer. In September 1979, Raskin began looking for an engineer who
could put together a prototype.
Bill Atkinson, a member of the
Apple Lisa team, introduced Raskin to
Burrell Smith, a service technician who had been hired earlier that year.
Apple's original concept for the Macintosh deliberately sought to
minimize the user's conceptual awareness of the operating system. Many
basic tasks that had required more operating system knowledge on other
systems could then be accomplished by mouse gestures and graphic
controls on a Macintosh. This would differentiate it from its
contemporaries such as
MS-DOS, which use a
command-line interface consisting of tersely abbreviated textual commands.
In January 1981,
Steve Jobs
completely took over the Macintosh project. Jobs and a number of Apple
engineers visited Xerox PARC in December 1979, three months after the
Lisa and Macintosh projects had begun. After hearing about the
pioneering
GUI technology being developed at
Xerox PARC from former Xerox employees like Raskin, Jobs negotiated a visit to see the
Xerox Alto computer and
Smalltalk development tools in exchange for Apple stock options.
[12]
The final Lisa and Macintosh operating systems use concepts from the
Xerox Alto, but many elements of the graphical user interface were
created by Apple including the menu bar, pull-down menus, and the
concepts of
drag and drop and
direct manipulation.
[13]
Unlike the
IBM PC, which uses 8 kB of system
ROM for
power-on self-test (POST) and basic input/output system (
BIOS), the Mac ROM is significantly larger (64 kB) and holds key OS code. Much of the original Mac ROM was coded by
Andy Hertzfeld, a member of the original Macintosh team. He was able to conserve precious ROM space by writing routines in
assembly language code optimized with "hacks," or clever programming tricks.
[14] In addition to the ROM, he also coded the kernel, the
Macintosh Toolbox, and some of the
desktop accessories (DAs). The
icons of the operating system, which represent
folders and
application software, were designed by
Susan Kare, who later designed the icons for
Microsoft Windows 3.0.
Bruce Horn and
Steve Capps wrote the
Macintosh Finder, as well as a number of Macintosh system utilities.
Apple was very aggressive in advertising their new machine. After it
was created, the company bought all 39 pages of advertisement space in
the 1984 November/December edition of
Newsweek
magazine. Apple was so successful in its marketing for the Macintosh
that it quickly outsold its more sophisticated predecessor, the
Lisa. Apple quickly developed a product named
MacWorks,
which allowed the Lisa to emulate Macintosh system software through
System 3, by which time it had been discontinued as the rebranded
Macintosh XL. Many of Lisa's operating system advances would not appear in the Macintosh operating system until System 7 or later.
Architecture
Compatibility
Early versions of Mac OS are compatible only with
Motorola 68000-family Macintoshes. As Apple introduced computers with
PowerPC
hardware, the OS was ported to support this architecture. Mac OS 8.1 is
the last version that could run on a "68K" processor (the
68040).
In systems prior to
PowerPC G3-based systems, significant parts of the system are stored in physical
ROM on the motherboard. The initial purpose of this is to avoid using up the limited storage of
floppy disks on system support, given that the early Macs have no
hard disk (only one model of Mac was ever actually bootable using the ROM alone, the 1991
Mac Classic
model). This architecture also allows for a completely graphical OS
interface at the lowest level without the need for a text-only console
or command-line mode: boot time errors, such as finding no functioning
disk drives, are communicated to the user graphically, usually with an
icon or the distinctive Chicago bitmap font and a
Chime of Death or a series of beeps. This is in contrast to
MS-DOS and
CP/M
computers of the time, which display such messages in a mono-spaced
font on a black background, and require the use of the keyboard rather
than a mouse, for input. To provide such niceties at a low level, early
Mac OS depends on core system software in ROM on the motherboard, which
also ensure that only Apple computers or licensed clones (with the
copyright-protected ROMs from Apple) can run Mac OS.
Mac clones
Several computer manufacturers over the years made
Macintosh clones that were capable of running Mac OS. From 1995 to 1997, Apple licensed Macintosh ROMs to several companies, notably
Power Computing,
UMAX and
Motorola. These machines normally ran various versions of classic Mac OS.
Steve Jobs ended the clone-licensing program after returning to Apple in 1997.
Support for Macintosh clones was first exhibited in System 7.5.1,
which was the first version to include the "Mac OS" logo (a variation on
the original
Happy Mac
startup icon), and Mac OS 7.6 was the first to be named "Mac OS"
instead of "System". These changes were made to disassociate the
operating system from Apple's own Macintosh models.
[15]
File systems
The Macintosh originally used the
Macintosh File System (MFS), a
flat file system with only one level of folders. This was quickly replaced in 1985 by the
Hierarchical File System (HFS), which had a true
directory tree. Both file systems are otherwise compatible. An improved file system named
HFS Plus ("HFS+" or "Mac OS Extended") was announced in 1997 and implemented in 1998.
[16]
Files in most file systems used with
DOS,
Windows,
Unix, or other operating systems have only one "
fork".
By contrast, MFS and HFS give files two different "forks". The data
fork contains the same sort of information as a file in other file
systems, such as the text of a document or the bitmaps of an image file.
The
resource fork
contains other structured data such as menu definitions, graphics,
sounds, or code segments that would be incorporated into a program's
file format on other systems. An
executable file might consist only of resources (including
code segments) with an empty data fork, while a
data file might have only a data fork with no resource fork. A
word processor
file could contain its text in the data fork and styling information in
the resource fork, so that an application which doesn’t recognize the
styling information can still read the raw text.
On the other hand, these forks would provide a challenge to
interoperability
with other operating systems. In copying or transferring a Mac OS file
to a non-Mac system, the default implementations would simply strip the
file of its resource fork. Most
data files
contained only nonessential information in their resource fork, such as
window size and location, but program files would be inoperative
without their resources. This necessitated such encoding schemes as
BinHex and
MacBinary,
which allowed a user to encode a dual-forked file into a single stream,
or inversely take a single stream so-encoded and reconstitute it into a
dual-forked file usable by Mac OS.
Release history
System 1, 2, 3 and 4
The early Mac OS (simply named "System") is easily distinguished from
many other operating systems from the same period because it does not
use a
command line interface; it was one of the first operating systems to use an entirely
graphical user interface or
GUI. It consists of two user-visible components: in addition to the
system kernel, there is the
Finder, an
application used for file management that also displays the
Desktop. The two files were contained in a folder directory labeled "System Folder", which contained other resource files, like a
printer driver, needed to interact with the System.
[6]
- System 1.0, 1.1, and 2.0 use a flat file system named Macintosh File System
(MFS). The Finder provides virtual folders that could be used to
organize files, but these are not visible from any other application and
do not actually exist in the file system. System 2.0 added support for AppleTalk and the newly introduced LaserWriter to use it.
- System 2.1 (Finder 5.0) introduced the HFS (Hierarchical File System) which has real directories. This version was specifically to support the Hard Disk 20 and only implements HFS in RAM; startup and most floppy disks remain MFS 400 K volumes.
- System 3.0 (Finder 5.1) was introduced with the Mac Plus, officially implementing HFS, 800K startup drives, support for several new technologies including SCSI and AppleShare, and Trash "bulging" (i.e., when the Trash contains files, it gains a bulged appearance).
- System 4.0 was released with the Mac SE and System 4.1 first shipped with the Macintosh II—these new machines required additional support for the first expansion slots, the Apple Desktop Bus (ADB), internal hard drives and, on the Mac II, lighter, color, larger displays and the first Motorola 68020 processor.[17]
These releases can only run one application, except for desk accessories, at a time, though special application shells such as
MultiMac[18] or
Switcher (discussed under
MultiFinder) could work around this. Changes in early Macintosh operating systems are best reflected in the version number of the
Finder, where major leaps are found between 1.x, 4.x, 5.x, and 6.x.
| System Software Release[6] |
System Version[6] |
Release Date[6] |
Finder Version[6] |
LaserWriter Version[6] |
Release Information[6] |
| Mac System Software |
1.0 (.97)[19] |
January 24, 1984[1][2] |
1.0 |
|
Initial Release |
| Mac System Software (0.1) |
1.1 |
May 5, 1984[1] |
1.1g |
|
Maintenance Release, Added Mountain scene, About box, Clean Up Command |
| Mac System Software (0.3 & 0.5) |
2.0 |
April 1985[20] |
4.1 |
|
Finder Update: Introduced multiple folders, "Shut Down" command, and
installation of a "MiniFinder" application for quickly launching any of
the chosen applications
System: Introduced screenshots using ⌘ Command+⇧ Shift+3
|
| Mac System Software[19][21][22] |
2.1[19] |
September 1985[19] |
5.0[21][22] |
|
Release for Hard Disk 20 support[19][21][22] |
| Mac System Software (0.7) |
3.0 |
January 1986[1] |
5.1 |
1.1[citation needed] |
Introduced with Mac Plus[1] |
| System Software 1.0 |
3.1 |
February 1986[1] |
5.2 |
1.1 |
|
| System Software 1.1 |
3.2 |
June 1986[23] |
5.3 |
3.1 |
Fixed problems with data loss, system crashes; updated Chooser and Calculator.[23] |
| AppleShare 1.0 |
3.3 |
January 1987 |
5.4 |
|
AppleShare 1.0 Work Station Installer disk (for the Macintosh 512K) |
| AppleShare 1.1[24] |
3.3[24] |
1987 |
5.5[24] |
|
AppleShare 1.1 Work Station Installer disk (for the Macintosh 512K)[24] |
| AppleShare 2.0[24] |
3.4[24] |
1988 |
6.1[24] |
|
AppleShare 2.0 Macintosh 512Ke Work Station Installer disk[24] |
| System Software 2.0 |
4.0 |
January 1987[1] |
5.4 |
3.3 |
Introduced AppleShare[citation needed] |
| System Software 2.0.1 |
4.1 |
March 2, 1987 |
5.5 |
4.0 |
Release for Macintosh II and SE. Updated LaserWriter Driver |
System Software 5
Beginning with version 5, both the System and Finder are incorporated under a single "System Software" moniker.
System Software 5 (also referred to as "System 5") added
MultiFinder, an extension which lets the system run several programs at once. The system uses a
cooperative multitasking
model, meaning that time was given to the background applications only
when the running application yielded control. A change in system
functions that applications were already calling to handle events makes
many existing applications share time automatically. Users can also
choose not to use MultiFinder, thereby sticking with using a single
application at a time as in previous releases of the system software.
System Software 5 is the first Macintosh operating system to be given
a unified "Macintosh System Software" version number, as opposed to the
numbers used for the System and Finder files. It was available for a
very short time and only in some countries, including the United States,
Canada and some European countries.
[which?]
System Software
Release[6] |
System
Version[6] |
Release
Date[6] |
Software Version[6] |
Release Information[6] |
| Finder |
MultiFinder |
LaserWriter |
| 5.0 |
4.2 |
October 1987[25] |
6.0 |
1.0 |
5.0 |
Initial Release |
| 5.1 |
4.3 |
November 1987 |
6.0 |
1.0 |
5.1 |
Updated LaserWriter Driver and new version of Apple HD SC Setup |
System Software 6
System Software 6 (also referred to simply as System 6) is a
consolidation release of the Mac OS, producing a complete, stable, and
long-lasting operating system. Two major hardware introductions
requiring additional support under System 6 are the
68030 processor and 1.44 MB
SuperDrive debuting with the
Macintosh IIx and
Macintosh SE/30. Later, it would include support for the first specialized laptop features with the introduction of the
Macintosh Portable.
From System 6 forward, the Finder would have a unified version number
closely matching that of the System, alleviating much of the confusion
caused by the often considerable differences between earlier Systems.
[26]
| System Version[6] |
Release Date[6] |
Finder Version[6] |
MultiFinder Version[6] |
LaserWriter Version[6] |
Release Information[6] |
| 6.0 |
April 1988 |
6.1 |
6.0 |
5.2 |
Initial Release |
| 6.0.1 |
September 19, 1988 |
6.1.1 |
6.0.1 |
5.2 |
Release for Macintosh IIx (1988) |
| 6.0.2 |
Late 1988 |
6.1 |
6.0.1 |
5.2 |
Maintenance Release |
| 6.0.3 |
March 7, 1989 |
6.1 |
6.0.3 |
5.2 |
Release for Macintosh IIcx (1989) |
| 6.0.4 |
September 20, 1989 |
6.1.4 |
6.0.4 |
5.2 |
Release for Macintosh Portable and IIci (1989) |
| 6.0.5 |
March 19, 1990[27] |
6.1.5 |
6.0.5 |
5.2 |
Release for Macintosh IIfx (1990) |
| 6.0.6 |
October 15, 1990 |
6.1.6 |
6.0.6 |
5.2 |
Not released because of AppleTalk bug [28] |
| 6.0.7 |
October 16, 1990 |
6.1.7 |
6.0.7 |
5.2 |
Official release for Macintosh LC, IIsi and Classic (1990) |
| 6.0.8 |
May 13, 1991 |
6.1.8 |
6.0.8 |
7.0 |
Updated printing software to match software of System 7.0 |
| 6.0.8L |
March 23, 1992 |
6.1.8 |
6.0.8 |
7.0 |
Limited maintenance release for Pacific customers |
System 7
On May 13, 1991, System 7 was released. It is a major upgrade to the Mac OS, adding a significant
user interface
overhaul, new applications, stability improvements and many new
features. Its introduction coincides with the release of and provided
support for the
68040 Macintosh line. The System 7 era saw numerous changes in the Macintosh platform including
a proliferation of Macintosh models, the 68k to
Power Macintosh transition as well as the rise of
Microsoft Windows, increasing use of
computer networking and the explosion in popularity of the
Internet.
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.
[citation needed] Accompanying this was a move to
32-bit memory addressing, necessary for the ever-increasing amounts of
RAM
available to the Motorola 68030 CPU, and 68020 CPUs with a 68551 PMMU.
This process involves making all of the routines in OS code use the full
32-bits of a pointer as an address—prior systems used the upper 8 bits
as
flags.
This change is known as being "32-bit clean". While System 7 itself is
32-bit clean, many existing machines and thousands of applications were
not, so it was some time before the process was completed. To ease the
transition, the "Memory" control panel contains a switch to disable this
feature, allowing for compatibility with older applications.
Another notable System 7 feature is built-in
cooperative multitasking. In System Software 6, this function was optional through the
MultiFinder. System 7 also introduced
aliases, similar to
symbolic links on
Unix,
shortcuts that were introduced in later versions of Microsoft Windows, and
shadows in IBM
OS/2.
System extensions were enhanced by being moved to their own subfolder; a subfolder in the
System Folder was also created for the
control panels. In System 7.5, Apple includes the
Extensions Manager, a previously third-party program which simplified the process of enabling and disabling extensions.
The Apple menu, home only to desk accessories in System 6, was made
more general-purpose: the user could now make often-used folders and
applications—or anything else they desired—appear in the menu by placing
aliases to them in an "Apple Menu Items" subfolder of the System
Folder. System 7 also introduced the following:
AppleScript, a
scripting language for automating tasks;
32-bit QuickDraw, supporting so-called "true color" 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, if MultiFinder is not running, when
launching an application. System 7 reimplements the Trash as a special
hidden folder, allowing files to remain in it across reboots until the
user deliberately chose the "Empty Trash" command.
System 7.1
System
7.1 is mainly a bugfix release, with a few minor features added. System
7.1 is not only the first Macintosh operating system to cost money (all
previous versions were free or sold at the cost of the floppies), but
also received a "Pro" sibling (version 7.1.1) with extra features.
System 7.1.2 was the first version to support PowerPC-based Macs. System
7.1 also introduces the System Enablers as a method to support new
models without updating the actual System file. This leads to extra
files inside the system folder (one per new model supported).
System 7.5
System
7.5 introduces a large number of new features, many of which are based
on shareware applications that Apple bought and included into the new
system.
[29][30]
On the newer PowerPC machines, System 7.5 may have stability problems
partly due to a new memory manager (which can be turned off),
[citation needed]
and issues with the handling of errors in the PowerPC code (all PowerPC
exceptions map to Type 11). These issues do not affect 68k-architecture
machines. System 7.5 is contemporary with Apple's failed
Copland effort as well as the release of
Windows 95, which coincides with Apple's purchase of several
shareware system enhancements to include as new system features.
Mac OS 7.6
Stability
improved in PowerPC-based Macs with Mac OS 7.6, which dropped the
"System" moniker as a more trademarkable name was needed in order to
license the OS to the growing market of third-party
Macintosh clone manufacturers. Mac OS 7.6 required 32-bit-clean ROMs, and so it dropped support for every Mac with a
68000 processor, as well as the
Mac II,
Mac IIx,
Mac IIcx, and
Mac SE/30.
| System Version[6] |
Release Information[6] |
| System 7.0 |
integrated MultiFinder always enabled |
| System 7.0.1 |
introduced with LC II and Quadra series |
| System 7.0.1P |
|
| System 7 Tuner |
update for both 7.0 and 7.0.1 |
| System 7.1 |
|
| System 7.1P |
|
| System 7.1P1 |
|
| System 7.1P2 |
|
| System 7.1P3 |
last "P" release with new features |
| System 7.1P4 |
|
| System 7.1P5 |
|
| System 7.1P6 |
|
| System 7.1 Pro |
version 7.1.1, combined with PowerTalk, Speech Manager, MacInTalk, Thread Manager |
| System 7.1.2 |
Macs equipped with a PowerPC processor |
| System 7.1.2P |
only for Performa/LC/Quadra 630 series, very quickly replaced by 7.5 |
| System 7.5 |
|
| System 7.5.1 |
System 7.5 Update 1.0—the first Macintosh operating system to call itself "Mac OS" |
| System 7.5.2 |
Power Macs that use PCI, usable only on these Power Macs and PowerBooks 5300, 190, and Duo 2300 |
| System 7.5.3 |
System 7.5 Update 2.0 |
| System 7.5.3L |
only for Macintosh clones |
| System 7.5.3 Revision 2 |
|
| System 7.5.3 Revision 2.1 |
only for Performa 6400/180 and 6400/200 |
| System 7.5.4 |
withdrawn within hours of release and replaced by 7.5.5 |
| System 7.5.5 |
last to support non-32-bit-clean Macs, including all with less than a 68030 CPU except the Macintosh LC |
| Mac OS 7.6 |
name formally changed because of the experimental clone program, although System 7.5.1 and later used the "Mac OS" name on the splash screen |
| Mac OS 7.6.1 |
proper PowerPC error handling introduced |
Mac OS 8
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 Jobs's goal of terminating third-party manufacturers'
licenses to System 7 and shutting down the
Macintosh clone market.
[31]
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; 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 one
shipped). This capability was provided by a new "appearance" API layer
within the OS, one of the few significant changes.
Apple sold 1.2 million copies of Mac OS 8 in its first two weeks of
availability and 3 million within six months. In light 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.
[32][33]
Mac OS 8.1
Mac OS 8.1 sees the introduction of an updated version of the
Hierarchical File System named
HFS+, which fixed many of the limitations of the earlier system (HFS+ continues to be used in the current
macOS, though it is set to be replaced by the
Apple File System).
There are some other interface changes such as separating network
features from printing, and some improvements to application switching.
However, in underlying technical respects, Mac OS 8 is not very
different from System 7.
Mac OS 8.5
Mac
OS 8.5 focuses on speed and stability, with most 68k code replaced by
modern code native to the PowerPC. It also improved the appearance of
the user interface, although the theming feature was cut late in
development.
| System Version[6] |
Release Information[6] |
| Mac OS 8.0 |
first version to require a 68040 processor, dropping support for the remainder of the Macintosh II series and other 68030 Macs. It also added support for the PowerPC G3 processor |
| Mac OS 8.1 |
last Mac OS release to run on a 68K processor, and it added support for USB on the iMac and added support for the HFS+ filesystem |
| Mac OS 8.5 |
first version to run solely on a PowerPC processor, and it added built-in support for Firewire. It also added Sherlock and added support for the Power Macintosh G3 |
| Mac OS 8.5.1 |
added bug fixes to lessen system crashes |
| Mac OS 8.6 |
included a new nanokernel for improved performance and Multiprocessing Services 2.0 support, improved PowerBook battery life, and added support for the PowerPC G4 processor |
Mac OS 9
Mac OS 9, the last major revision of the classic Mac OS, was released on October 23, 1999.
[8] It is generally a steady evolution from Mac OS 8. Early development releases of Mac OS 9 were numbered 8.7.
Mac OS 9 added improved support for
AirPort wireless networking.
It introduced an early implementation of multi-user support. Though not
a true multi-user operating system, Mac OS 9 does 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 provides a much improved memory implementation and management.
AppleScript was improved to allow
TCP/IP and networking control. Mac OS 9 also makes the first use of the centralized
Apple Software Update to find and install OS and hardware updates.
Other new features included its on-the-fly
file encryption software with
code signing and
Keychain technologies, Remote Networking and
File Server packages, and 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 the 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 run natively on Mac
OS X as well. Other changes were made beginning with the Mac OS 9.1
update to allow it to be launched in the
Classic Environment within Mac OS X.
The final update to the classic Mac OS was version 9.2.2, released on December 5, 2001.
[34]
| System Version[6] |
Release Information[6] |
| Mac OS 9.0 |
initial retail version of Mac OS 9 |
| Mac OS 9.0.2 |
|
| Mac OS 9.0.3 |
|
| Mac OS 9.0.4 |
|
| Mac OS 9.1 |
included with Mac OS X 10.0 |
| Mac OS 9.2 |
update for improved Mac OS X compatibility |
| Mac OS 9.2.1 |
|
| Mac OS 9.2.2 |
final release of classic Mac OS |
Transition to Mac OS X
macOS (originally named "Mac OS X" until 2012 and then "OS X" until 2016)
[35]
is Apple's current Mac operating system that officially succeeded the
classic Mac OS in 2001. Although it was originally marketed as simply
"version 10" of Mac OS, it has
a history that's largely independent of the earlier Mac OS releases.
The macOS architectural legacy is the successor to
Mac OS 9 and the classic Mac OS legacy. However, unlike the classic Mac OS, it is a
Unix-based operating system
[36] built on
NeXTSTEP and technology developed at
NeXT from the late 1980s until early 1997, when Apple purchased the company and its CEO
Steve Jobs returned to Apple.
[37] macOS also makes use of the
BSD codebase and the
XNU kernel,
[38] and its core set of components is based upon Apple's
open source Darwin operating system.
An early version of the operating system,
Mac OS X Server 1.0, was released in 1999. It retains the "platinum" appearance from the classic Mac OS and even resembles
OPENSTEP in places. The desktop version,
Mac OS X 10.0, followed on March 24, 2001, supporting the new
Aqua user interface. Since then,
several more versions of the operating system have been released. Mac OS X was renamed "OS X" in 2012 and "
macOS" in 2016.
Users of the classic Mac OS generally upgraded to Mac OS X, but it
was criticized in its early years as more difficult and less
user-friendly than the original Mac OS, for the lack of certain features
that had not yet been reimplemented in the new OS, for being slower on
the same hardware (especially older hardware), and for incompatibilities
with the older OS.
[39]
Because drivers (for printers, scanners, tablets, etc.) written for the
older Mac OS were not compatible with Mac OS X, and due to the lack of
Mac OS X support for older Apple computers, some Macintosh users
continued using the older classic Mac OS for a few years after the
original release of Mac OS X.
Steve Jobs encouraged people to upgrade to Mac OS X by staging a mock
funeral for Mac OS 9 at
WWDC 2002.
[40]
Classic
PowerPC versions of Mac OS X up to and including
Mac OS X 10.4 Tiger include a
compatibility layer
for running older Mac applications, the Classic Environment. Originally
codenamed the "blue box", the environment runs a nearly complete Mac OS
9 operating system, version 9.1 or later, as a Mac OS X application.
This allows applications that have not been ported to the
Carbon API
to run on Mac OS X. This is reasonably seamless, though "classic"
applications retain their original Mac OS 9 appearance and do not gain
the Mac OS X "Aqua" appearance.
Early
New World ROM
PowerPC-based Macs shipped with Mac OS 9.2 as well as Mac OS X. Mac OS
9.2 had to be installed by the user—it was not installed by default on
hardware revisions released after Mac OS X 10.4. Most well-written
"classic" Mac OS applications function properly under this environment,
but compatibility is assured only if the software was written to be
unaware of the actual hardware and to interact solely with the operating
system. The Classic Environment is not available on
Intel-based Mac systems due to the incompatibility of
Mac OS 9 with the
x86 hardware.
Emulation
68k emulators
Third-party Macintosh
emulators, such as
vMac,
Basilisk II, and
Executor, eventually made it possible to run the classic Mac OS on
Intel-based PCs. These emulators were restricted to emulating the
68k series of processors, and as such most couldn't run versions of the Mac OS that succeeded 8.1, which required
PowerPC
processors. Most also required a Mac ROM image or a hardware interface
supporting a real Mac ROM chip; those requiring an image are of dubious
legal standing as the ROM image may infringe on Apple's intellectual
property.
A notable exception was the
Executor
commercial software product from Abacus Research & Development, the
only product that used 100% reverse-engineered code without the use of
Apple technology. It ran extremely quickly but never achieved more than a
minor subset of functionality. Few programs were completely compatible
and many were extremely crash-prone if they ran at all. Executor filled a
niche market for porting 68k Mac applications to
x86 platforms; development ceased in 2002 and the source code was released by the author in late 2008.
[41]
Emulators using Mac ROM images offered near complete Mac OS
compatibility, and later versions offered excellent performance as
modern x86 processor performance increased exponentially.
Apple included its own
Mac 68k emulator that ran seamlessly on all PowerPC-based versions of the classic Mac OS.
PowerPC emulators
In comparison with 68k-emulator development,
PowerPC
support was difficult to justify due to the anticipated wide
performance overhead of an emulated PowerPC architecture. This would
later prove correct with the
PearPC project, despite the availability of 7th and 8th generation
x86 processors employing similar architecture paradigms present in the PowerPC.
[citation needed] Nevertheless, the PearPC emulator is capable of emulating the
PowerPC
processors required by newer versions of the Mac OS. However, it is no
longer maintained, and like many emulators, it tends to run much slower
than a native
operating system would.
[citation needed]
Another PowerPC emulator is
SheepShaver, which has been around since 1998 for
BeOS on the PowerPC platform, but in 2002 was
open sourced,
and efforts began to port it to other platforms. Originally it was not
designed for use on x86 platforms and required an actual PowerPC
processor present in the machine it was running on similar to a
hypervisor. Although it provides PowerPC processor support, it can run only up to
Mac OS 9.0.4 because it does not emulate a
memory management unit.
Other examples include ShapeShifter (by the same developer that created
SheepShaver),
Fusion, and iFusion. The latter ran classic Mac OS with a PowerPC
"coprocessor" accelerator card. Using this method has been said to equal
or better the speed of a Macintosh with the same processor, especially
with respect to the
68k series due to real Macs running in
MMU trap mode, hampering performance.
[citation needed]
Apple's
Rosetta was a PowerPC emulator for
Intel-based Macs, but it did not support the classic Mac OS.
Timeline
See also
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