OS/2 had many flaws but its multitasking was unseen on a PC at the time. I remember formatting a floppy while running two 16-bit Windows sessions (which were communicating with each other) and multiple DOS windows, thinking I was in the future.
Even Windows 95 was limited by many system calls being funneled through single threaded BIOS or DOS 16-bit land.
That's my reason for switching to Linux, back in the Slackware days.
Back when CD burners were still uncommon, I got as a gift a japanese, SCSI-based one. With my hardware, I'd lose a CD if I forgot to disable the screensaver - the amount of disk seeks required to load the screen saver executable was enough to starve the buffer, and I'd get a buffer underrun every single time.
So, one time I was trying a linux system, and had to do a last-minute presentation, which required files on a floppy drive. For some reason, I had no usable floppies and had to format one, and I couldn't wait for the burn to finish.
So I inserted the drive and, fully expecting to lose the CD, called fdformat. cdrecord didn't even flinch, the buffer was still full when the format finished.
I only ever booted Windows from then on to play games.
Sinclair QDOS which ran on the Sinclair QL did preemptive multitasking on a 128KB machine (buggy as heck when it came out but it did precede the Amiga by almost a year and half).
Yes, the Amiga had proper honest multitasking. A normal boot of an Amiga system would typically result in over twenty processes running in the background. In fact, its particular style of multitasking (static absolute priorities) was well-suited to real-time operation. Back in the days when CD writers could create coasters from buffer under-runs, I had more success writing CDs using my 25MHz Amiga than my 400MHz PC. Also, it was a microkernel system with things like device drivers and filesystems as separate processes, which had some fairly nifty consequences. For instance, it took Linux ages to lose its single kernel spinlock, which was a problem because of the huge amount of stuff done in kernel space. The thing the Amiga didn't have (mostly because of lack of hardware capability) was memory protection.
The Amiga 1000 first came out with 256KB of RAM. It didn't have much space left after the OS had booted up though. It was the Amiga 500 that came out a little later that had 512KB.
Many of the people I knew in the beginning of 1990's ended up running either DESQview or OS/2. And that was because they were running either one node bulletin board system on their only desktop computer or they had a multi node BBS on their dedicated BBS computer.
Around that time I had updated from 1200 bps to 2400 bps to 14400 bps modem. Mostly the multitasking was running smooth enough to provide reasonably speedy BBS experience even for the 14k4 caller. The multitasking mostly was visible when the system was building and compressing the QWK archive for offine message reading (Blue Wave FTW).
In the very beginning of the 90's programmed a BBS and had it running under Desqview. In 1994 had to build a data bank accessible by modem, and based on my bbs to build it, but used OS/2 as multitasker, which made a big difference in stability.
In 1996 had to put access to that data via internet, and used the same OS/2 box for both modem access and an internet server with most of the usual services (mail/web/dns/proxy).
It was very reliable (really don't remember reboots, maybe it was mostly for upgrades), impressed me when i realized that i created a 16mb vector in that 16mb server with everything running normally, and loved WPS (not sure which today's desktop had so good integration with fs) and rexx (parsing without regexes was good, but later learnt how limited i was).
I was constantly listening to modules (first with DMP and later with Cubic Player) and DOS shelling from the player to do something else. That something else being editing ascii/ansi art or programming in Turbo Pascal. Because the module playing was done done in TSR, the players at the time could not switch to the next song in the playlist unless you returned to the player. When the music ended I had to quit the application I was working in and "exit" from DOS shell to give control back to player software. And then back to DOS shell and into the application.
One of the cool things about OS/2 is that it changed the sound the floppy drive made as it track-seeked. Rather than a chunk-chunk sound, it was more of a buzzing noise.
It almost seems too early to reminisce about this stuff. My first computers were a TRS-80 clone and a Commodore 64, but this is the era in which I really started to get into computers: the Solaris and NeXT ads in Byte and PC Magazine, with impressive looking screenshots of a busy computer; the Mac IIfx briefly taking the clock speed crown at a whopping 40 MHz; wondering if I'd take an Amiga or a Mac to college, then settling on a 486SX from Gateway.
In college I really wanted to like OS/2 2.0 (and later 2.1), but driver problems with the Diamond video card were a constant problem. (If only we'd sprung for the ATI Graphics Ultra Pro!) I had a copy of DeScribe; later sold it to someone through the ISCA BBS.
My impression at the time was that Microsoft executed so much better than its competitors, offsetting its weaker Office products with a better UI, which in turn gave you a reason to run Windows. I later attributed its success much more to its ruthless business practices.
This article brings the focus on the strategic vision: betting big on clones; belatedly embracing the Internet; hammering away at PDAs and tablets, yet losing big to the iPod, iPhone, et al. Sometimes we predict the future, and sometimes we make it.
Also VMS qualifies as a fully memory-protected, preemptive OS:
The real innovation that Windows and OS/2 did was to take fully preemptive OSes and put them in marginal hardware (at the time) like PCs.
You are correct, but I was referring to desktops, and the particular example is Coherent from Mark Williams Company which was demonstrated running on an IBM PC at the National Computer Conference show in Houston in 1983. Minix came in 1987, if I recall correctly.
About 1985 IBM had a product called TopView that ran a multitasking supervisor on top of DOS and could do real multitasking with the right disk drivers. No protected memory though. TopView was really memory heavy, though -- you gave up at least 160KB just with TopView. Two guys created a TopView clone called Mondrian that ran in just 40K, and ran much faster. Those two guys were Nathan and Cameron Myhrvold. Mondrian was sold to Microsoft and those two guys went with it. Mondrian was a really clever engineering feat.
Oh, you made me remember again. I forgot that little detail of formatting. In those days formatting was a common practice, right now unless you want to do a wipeout clean install or prepare a new USB for other file system you don't need to format :).
Even Windows 95 was limited by many system calls being funneled through single threaded BIOS or DOS 16-bit land.