104 votes
Accepted

Does "Disk Operating System" imply that there was a "non-disk" Operating System?

The term "Disk Operating System", or commonly "DOS", was used in the early days of personal computing to distinguish operating systems that also contained software for supporting disk devices, since ...
Brian H's user avatar
  • 60.5k
103 votes
Accepted

What key factor led to the sudden commercial success of MS Windows with v3.0?

Stephen Kitt covers the bases well, but I think the majority of the reason relates to fact that Windows 3.0 finally brought 286 protected mode execution to the masses. Even though the 80286 was first ...
mschaef's user avatar
  • 4,816
95 votes

What key factor led to the sudden commercial success of MS Windows with v3.0?

There were a number of factors involved. Windows 3.0 introduced a more refined user interface than available in Windows 2.0: more colours, proportional fonts everywhere, smaller icons, and MDI ...
Stephen Kitt's user avatar
85 votes
Accepted

Why did Windows 95 crash the whole system but newer Windows only crashed programs?

You are comparing apples to motorcycles. Windows 95 traces its lineage back through Windows 3.x all the way to Windows 1.x and MS-DOS/PC-DOS, themselves inspired by CP/M. It was conceived and ...
user's user avatar
  • 5,276
82 votes
Accepted

How exactly did Windows become the OS of the home PC?

The short version is that Windows became the de facto operating system thanks to Microsoft’s business acumen (or shenanigans, depending on your point of view), marketing, skilled developers, a strong ...
Stephen Kitt's user avatar
81 votes
Accepted

Were later MS-DOS versions still implemented in x86 assembly?

C did exist when DOS was developed, but it wasn’t used much outside the Unix world, and as mentioned by JdeBP, wouldn’t necessarily have been considered a good language for systems programming on ...
Stephen Kitt's user avatar
80 votes

Does "Disk Operating System" imply that there was a "non-disk" Operating System?

It doesn't imply that it's the disk operating system so much as it implies that it's the disk-operating system. You could boot an Apple II from ROM, enter and run BASIC programs, load programs from ...
hobbs's user avatar
  • 4,754
71 votes
Accepted

Why was BASIC built into so many operating systems?

Having a programming language built-in gave you a multi-purpose tool into your hands at the flick of a switch (power on). As to the choice of BASIC vs. other programming languages, microcomputer ...
blubberdiblub's user avatar
66 votes
Accepted

How should we interpret Dave Cutler's criticism of Unix?

The I/O model on "Cutler systems" – RSX-11M, VAX/VMS, Windows NT – is an asynchronous packet-driven I/O model, rather than the fundamentally synchronous I/O model of Unix. At its core, you ...
dave's user avatar
  • 35.2k
57 votes
Accepted

What was the first operating system called DOS?

DOS/360 (As distinct from TOS/360, the tape OS) Announced at the end of 1964 per Wikipedia.
dave's user avatar
  • 35.2k
54 votes

Why did "protected-mode MS-DOS" never happen?

16-bit protected mode DOS did sort of happen: Concurrent DOS 286 and FlexOS 286 were able to run some DOS applications in protected mode (this involved complex LOADALL shenanigans and revealed bugs in ...
Stephen Kitt's user avatar
53 votes
Accepted

Which original retrocomputer OS's are still maintained and updated today, for original hardware?

My previous research into retrocomputer OS updates has led me to the following list. For each retrocomputer OS, the date and version of the latest update released at time of posting is included. The ...
Brian H's user avatar
  • 60.5k
46 votes

Why was BASIC built into so many operating systems?

Having BASIC available for the machine was a selling point so early adopters wouldn't have to wait for software to become available--they could write what they need themselves, and they wouldn't need ...
snips-n-snails's user avatar
46 votes

Does "Disk Operating System" imply that there was a "non-disk" Operating System?

The term DOS pre-dates the personal computer by a looong way: the term DOS/360 was first coined by IBM in 1964 as a new operating system for their System/360 mainframe computers, to replace TOS (tape ...
JavaLatte's user avatar
  • 561
43 votes
Accepted

What was the first operating system to be called an "operating system"?

As is often the case, a candidate for the first system to be described by its authors as an “operating system” is the Atlas supervisor, described in the eponymous paper published in December 1961, ...
Stephen Kitt's user avatar
42 votes

Why was BASIC built into so many operating systems?

Nobody so far has said the magic words, which is Microsoft BASIC. First developed for the Altair 8800 (the first commercially successful personal computer!), Microsoft spent a lot of energy making ...
Gaurav's user avatar
  • 523
40 votes

Why did Windows 95 crash the whole system but newer Windows only crashed programs?

The decision about whether to kill a process or crash the OS generally depends on whether the problem can be isolated to the process. For example, if a running process in user mode attempts to read ...
dave's user avatar
  • 35.2k
39 votes
Accepted

What's the most recent version of AmigaOS?

A simple question, with a surprisingly complex answer... Really TL;DR Hyperion released Hotfix 3.2.2.1 on April 23, 2023 TL;DR The latest version of each of the main derivates of AmigaOS are: Branch ...
Richard Downer's user avatar
38 votes

Were later MS-DOS versions still implemented in x86 assembly?

MS-DOS (by which I mean the underlying IO.SYS and MSDOS.SYS files) was written in assembly through the first half of the 1990s. In 1995 for Windows 95, which was bootstrapped by what you would call MS-...
skew's user avatar
  • 481
38 votes

Processor and operating systems for automatic lifts/elevators

If I need to be more specific about the meaning of 'intelligence' then I'm happy to restrict this to the first use of one or other elevator algorithms All the algorithms mentioned in that post have ...
Raffzahn's user avatar
  • 219k
38 votes
Accepted

First use of an OS in gaming consoles?

TL;DR: For early consoles, having an OS was the norm; lacking one was an exception Even the very first second-generation consoles - that is, the ones using a micro-processor (*1) - commonly had some ...
Raffzahn's user avatar
  • 219k
36 votes

Were later MS-DOS versions still implemented in x86 assembly?

From The OS/2 Museum page about DOS3: "The new ATTRIB.EXE utility allowed the user to manipulate file attributes (Read-only, Hidden, System, etc.). It is notable for being the first DOS utility ...
No'am Newman's user avatar
35 votes

How exactly did Windows become the OS of the home PC?

The other answers include a lot of sound historical information about how Windows evolved into its dominant role on PC's in both the home and business environment. But I think the most fundamental, ...
Brian H's user avatar
  • 60.5k
35 votes
Accepted

What was this OS / Application on a 80286?

Since the computer was a gift from your aunt, working for IBM, the screen split in four reminds me immediately of the IBM PS/1’s “4-quadrant” interface: (The screenshot above is from IBMulator, an ...
Stephen Kitt's user avatar
33 votes
Accepted

Where does the hierarchical directory structure originate from?

The first hierarchical system capable of supporting arbitrary directory structures was designed for Multics, which pre-dates Unix. It is described in A General-Purpose File System For Secondary ...
Stephen Kitt's user avatar
33 votes

Late 1970s and 6502 chip facilities for operating systems

The simple answer is that early operating systems for the systems you mention did not provide those features. Apple DOS, for example, makes no use of interrupts, and has no concept of processes or ...
RETRAC's user avatar
  • 13.6k
31 votes
Accepted

What was the first operating system to feature a separate kernel?

Reading through Per Brinch Hansen's The evolution of operating systems paper, I get the impression the two main candidates for operating systems with identifiably separate kernels are Dijkstra's THE ...
Stephen Kitt's user avatar
31 votes

Why was preemptive multitasking so slow in coming to consumer OS's?

Memory protection. It's not that preemptive multi-tasking is expensive, or hard. It's not. It's easy. It costs (or can cost) essentially the same as cooperative multitasking. You have to save process ...
Will Hartung's user avatar
  • 12.2k
29 votes
Accepted

The origins of fork()

The fork() system call is definitely older than the C language because it already existed in the UNIX v0 draft, page 18 of the PDF, when the C language hasn't been conceived yet. The mechanism was ...
Leo B.'s user avatar
  • 18.9k

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