That's not really true. The 8088 had anything needed to make a system multitasking-capable: Software interrupts, and a timer. The software interrupts were (over)used to provide OS-level calls, and could easily have doubled as task switchers, while the timer allowed for a time-slicing mechanism. The only thing lacking was security rings, but it seems that the first versions of UNIX didn't run on hardware that supported security rings either. The modern embedded multitasking RTOS called ThreadX runs everything in ring 0 on ARM processors. While that's not a good idea for multi-user OS's, it still allows multi-tasking.
The biggest issue with early PCs is that they had inadequate OS services, so too many programs would directly program the hardware to accomplish their tasks. Those programs tended not to play well with multitasking front-ends.
However, as mentioned above, DESQView was a multitasking front-end that ran well-behaved programs on 8088 processors.
By your definition a 6502 that could JMP to new address and support event driven interrupts is multitasking. Sorry the 8088 was not able to multitask nor the 286.
Yes I have used Desqview/X ... the X version was pretty good but you need a massive expense hardware. But the point of the discussion is home users. Early OS/2 , VM/386 and Desqview/X all could multitask to some degree but who the hell the home user could afford any of this as needed maxed out processor and memory specs to do any type of reasonable multitasking. In 1992 a 8088 Dell with 640K and CGA was $1199. A 20 mhz new 386 range was $4000-$8000!!! Who the hell could afford that in 1992?
References from Byte Magazine Nov 1988 :
The Dell Computer Store -- Also note the i386 Sun Workstation ($10K and could ONLY run 3 DOS windows at AT performance), OS/2 (at this time only did one DOS session!) VM/386, and Concurrent DOS articles in this issue.
It's very clear you are confusing mid late 90's technology in your discussion.
Though the only true multitasking system outside of Unix workstation was the Archimedes / RiscPC which was ARM based (yes same descended ARM we have today).
My point is in early 90's and early 80's for home users only Unix workstation could do modern multitasking ie more than 3 or more instances before performance is completely impractical and really not desirable beyond two.
Edited by thetick1, Sun Mar 17, 2019 3:56 PM.