It's eduction's choice of metric, not mine, and by that "multithreaded, preemptive multitasking OS" metric, OS/2 1.0 qualifies. eduction didn't say anything ab

It's eduction's choice of metric, not mine, and by that "multithreaded, preemptive multitasking OS" metric, OS/2 1.0 qualifies. eduction didn't say anything about graphics. Presentation Manager was available in 1988, by the way, not 1990. Petzold's book on it came out in 1989. First (and only) edition sitting on my bookshelf as I type this.