Amiga Multitask

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Let's not forget about Quarterdeck Desqview and Desqview/X. It ran on a 386 with 640kb of RAM and if you had extra memory, it could be mapped by QEMM and made usable by Desqview.
 
1985 was an interesting year because Desqview was released in July, AmigaOS was released in October,  and Windows followed shortly after in November.
 
Desqview was actually the first multi-tasking OS I used and shortly after that I purchased my Amiga 1000.
 
It was amazing what programmers were able to do with such little resources back then.
 
These days, I think most programmers take for granted the abundance of resources available (GB's of RAM, TB's of HD, etc, etc). I think it makes for lazy programming and a constant bloat of our OS's and applications.
 
That's why I like to look back and use some of these great machines of those times; it reminds you of what can be done within confined specs.

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There is a difference between multi-threading and multi-tasking.
 
The C64 was my first computer and as much as I can remember, there was no way to task switch and have more than 1 open application and switch between them.
 
The C64 was an amazing piece of hardware for it's time, but, I think Commodore really set the bar when they created The Amiga.
 

There were multitasking implementations for the C64
 
It's actually very easy to do on the C64 simply by setting up a suitable interrupt, since you have so little state to save/load, and then just swap the return addresses around before you leave the interrupt handler.
 
Of course, it's not very *useful* on a machine that slow - the closest most people would get would be the interrupt handler in parallel with a main "thread".
 
But at least one BASIC extension offered pre-emptively multi-tasking BASIC. Lightning BASIC perhaps? I believe it was up 3 BASIC "threads" in parallel + sprite animations.
 
(EDIT: It was Laser Basic from OASIS I remember, based on "White Lightning" which had a boat-load of other features too - there a demo of some of it here: http://www.youtube.com/watch?v=H8609Pel_RU )

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Holy heck... OS/2 lives?? I thought that was long gone.
 
I'd bet there is a linux kernel running under eComStation.. lol..
 

@desiv
 
You might be interested to know OS/2 lives.
http://www.ecomstation.com

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I know.
 
The thread was about: what was reality, not what was possible.
 

That's because the OS doesn't have preemptive multitasking, not because the C64 can't do it (it's easy to do, actually).

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Dont forget about Xenix. It ran very well on the 286 and 386 platform.
 

The 6809, yes. The 68K, yes. Early Intel processors? Not well at all.
Minix was probably the only example of this that worked reasonably well (until the '386).