When the PDP-10 was introduced, there were 5 variant operating systems listed in the 1968 PDP-10 Systems User's Guide, directed at more or less capable hardware configurations. From the chapter "Single-User Monitors":
Monitor 10/10: A single-user Monitor for an 8K paper tape system. Includes an I/O Controller, run-time selection of I/O devices, job-to-job transition, job save and restore features, and memory dumps.
Monitor 10/20: A single-user Monitor for an 8K DECtape system. Includes the same versatile features as the 10/10.
Monitor 10/30: A single-user Monitor for 16K and larger systems. Includes the same versatile features as the 10/10.
And from "Time-Sharing Monitors":
Monitor 10/40: A proven multiprogramming time-sharing system which includes an I/O controller, run-time slection of I/O devices, job-to-job transition, job save and restore features, and memory dump facilities. All of these features are incorporated with concurrent real-time processing, batch processing, and time sharing.
Monitor 10/50: A full-range, disk-swapping, multiprogramming time-sharing system incorporating all of the features of Monitor 10/40 with greatly extended capability.
Of course, the operating system we all call "Tops-10" is a late development of the 10/50 Monitor, with the addition of "Level D" disk service (i.e., directories).
What I would like to find, just for historical completeness, are copies of the 10/30 and 10/40 Monitors, at the very least. I (think I) know that Rich Cornwell has some early 10/50 monitors, but I don't think we've seen anything else between the PDP-6 Monitor and the 10/50. I'd be very happy to be wrong, but I want to plant a stake so that they aren't forgotten.
When the PDP-10 was introduced, there were 5 variant operating systems listed in the 1968 PDP-10 Systems User's Guide, directed at more or less capable hardware configurations. From the chapter "Single-User Monitors":
And from "Time-Sharing Monitors":
Of course, the operating system we all call "Tops-10" is a late development of the 10/50 Monitor, with the addition of "Level D" disk service (i.e., directories).
What I would like to find, just for historical completeness, are copies of the 10/30 and 10/40 Monitors, at the very least. I (think I) know that Rich Cornwell has some early 10/50 monitors, but I don't think we've seen anything else between the PDP-6 Monitor and the 10/50. I'd be very happy to be wrong, but I want to plant a stake so that they aren't forgotten.