In the movie "Steve Jobs" with Michael Fassbender, it is implied that Jobs started NeXT, not to sell hardware, but to develop a new OS and have Apple buy the company, only for the OS. We all know the history and know that this is exactly what happened.

Now I am diving a little into Apple OSs and find that the OS Apple had/developed while Jobs was away, was the "Classic Mac OS". In the movie it is said that Apple "really needed" a new OS.

This all made me wonder: what was so bad about the classic Mac OS?

  • 2
    for its time, not a durn thing... but for moving forward, it had significant limitations for growth.
    – MmmHmm
    Aug 23, 2017 at 15:55
  • 2
    Bad Movie. Implications from that, it was not what happened. This is skewed history or rewritten in hindsight. Classic Mac OS, named 'System', was developed initially directly under Jobs while he was at Apple. What was 'bad' about the OS when Jobs was bought back was in large part the direct result of his own decisions during initial development. And when he left Apple he certainly had no intention that his new company should be bought by Apple one day. It was called NeXT partially because he realised it was time for him to move on. Aug 23, 2017 at 17:49
  • 1
    Since Jobs always thought in terms of an appliance salesman this next thing really was a thing: a new dream machine, whole package. The OS as an integral part, of course. But wholly independent from Apple, built to compete against Apple. Incompatible. Not the best starting point to be bought. It wouldn't fit. As we had to learn after 1997. Aug 23, 2017 at 17:58
  • @LangLangC your comments could easily be made into an answer... Aug 23, 2017 at 18:03
  • 1
    @LangLangC all due respect, you are saying System (1-9)‘s "deficiencies" are due to Jobs' design choices. However Apple led the market in innovation. So you can hardly call them deficiencies. Nevermind that no CPU of that age could support memory security, which is the keystone to the rest... Your logic essentially says the Wright Brothers could've just started with the 747. Aug 23, 2017 at 18:15

2 Answers 2


Did Not Multitask

It had limited, cooperative multi-tasking, but this was spliced on top of a fundamentally single-tasking OS. That meant if a (say, background) task was greedy or had a problem, the whole system ran badly or locked up.

There was a point when Microsoft was "eating Apple's lunch" because multitasking worked so much better on Windows - and Apple lost a lot of market share.

No crash protection

It did not have any way to contain the failure of one particular app. So when one app "crashed", the system crashed. Being able to run multiple applications concurrently, to say nothing of the array of often dozens of desk accessories, extensions and whatnot, that created a huge vulnerability.

It was common for a Mac to come into the shop with so many desk accessories installed that you had to scroll to see them all. I said "They did to this Mac what a pimp does to a Cadillac." No wonder it was in the shop.

No security

Also related, there was no hardware-based memory protection, so one app could scribble another app's memory from a simple bug.

This also meant an application, DA etc. could snoop on the contents and activities in system memory. What's the point of having password logins when your free screensaver DA can simply scan memory looking for the passwords?

Without an ability to keep applications contained, this also meant filesystem security was a lost cause. Among other things, there was no way to keep applications from damaging or hacking the OS.

Viruses started on the Mac, you know. This sort of thing is why. They also virtually ended when OS X came out.

No shell

Okay, that only matters to a few people, but there was absolutely no robust back-end from which to keyboard/script system tasks. No way to, say, "rsync" a directory to a backup; you had to rely on packaged products. Of course there were developer tools, but that was not readily available to end users, you had to sign up and if I recall, pay some fees.

Upgrading OS 8/9 to proper multitasking was a hard problem - a veritable Gordian knot. It needed an "Alexander the Great" solution, and that's where Steve came in.

  • 1
    I've long wondered if Apple intentionally avoided adding features like a true shell or even a basic command-line, and many features that Enterprise-size customers would want, to avoid needing to keep that market segment continually placated: the iPhone shows you can be very profitable and successful just by focusing on the consumer base and leaving "boring" business customers to the competition like Blackberry (which sure worked out for them...)
    – Dai
    Aug 23, 2017 at 17:19
  • 2
    @Dai I would guess that it stemmed more from the desire to turn the computer into a household appliance: they wanted remove the requirement for computer users to be computer experts. Aug 23, 2017 at 17:23
  • 1
    OS was also too exotic in terms of networkability, filesystem, data structure of ordinary files. Anyone remember binhex: resource forks and downloading raw Macintosh files correctly? Aug 23, 2017 at 18:03
  • 1
    @Wowfunhappy It was a small program that could run from the Apple menu. Notepad, calendar, calculator, that kind of thing. What's important is you could use it while in another program, which is a big deal in a non-multitasking OS. That, with control panel addons etc. could turn a stock Mac into something unrecognizable, and unstable :) Aug 27, 2017 at 3:16
  • 1
    The classic MacOS had a few issues, but overall it was light years ahead of today's operating systems, including MacOS X. Why? Because it did a very good job of sealing up all the leaky abstractions. It was designed from inside out to be usercentric, not programmer centric. Try moving an open file on Windows and compare how elegantly MacOS handles it.
    – ATL_DEV
    Feb 5, 2019 at 4:01

From the Wikipedia article on Classic Mac OS:

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.

Not the answer you're looking for? Browse other questions tagged .