IOW, task. The PDP-10 product line discovered that the two never mixed. Realtime, at...
The trick was RSX11M and the big boy M+ were real-time OS's that did a little timesharing on the side. VAX-VMS was similar in that the design was to allow timesharing if there was no real-time demand on the system.
I brought a VAX to a standstill when diagnosing an intermittant floating point error (which turned out to be in the CPU rather than the FP780) by running a number of copies of the FPU diag in real time in a special batch queue I created to loop them for a while until the diag failed (which happened finally under load). Programmers runnning EDT thought the box crashed when the EDT keypresses stopped registering on the screen.
'Course it was VAX-VMS and when the real-time stuff cleared out of the queue business as usual continued...
IAS was pretty good. Newspapers around here used it as did the military.
I wish DEC would've opened the source. They kept it when Mentec got the rest of the 11 OS's (probably due to gov't military contract requirements for extended support).
Never found out why it wasn't more common commercially. Probably was more costly.
At that time, DEC's PDP-11 operating systems were all over the shop, with DOS, RSTS, RT-11 and RSX in perma-battle, but 11-M version 1, which was pure Cutler, must have...
Bill -- -- digital had it THEN. Don't you wish you could still buy it now! pechter-at-ureachtechnologies.com