On 2012-07-02 17:01, Bob Armstrong wrote: Was that the RTOS used with the T-11 (the first single-chip PDP-11?) I seem to remember that it was used as the RTOS in the LA-120 printer. Oh, and I almost forgot - the only use of RT11 that I know of for an "embedded" system was the CFEs for the VAX 780 and 8600 (on a 11/03 in the former and a PRO in the latter). Are there any more? The 86x0 uses a T11, and runs RT-11. You can even get into the RT-11 system and play around, if you want to. I'm not sure how complete a RT-11 system you had on the VAX-11/780, since it was living on a single RX01 (or was that RX02?) The PRO was for later VAXen. 8800-range, I think. Anyway, that one ran P/OS, which is RSX derived. Johnny