On Fri, Oct 20, 2023 at 1:46 PM Henry Bent <henry.r.b...@gmail.com> wrote: > I have a SIMH installation of Ultrix-11 3.1 on RL02 drives. Two RL02s is > enough for a base system and four (which would be what the DQ614 provides, if > it worked) would be more than enough for sources and work, etc.
Yes. 40MB should be plenty of room. 10MB was definitely not enough for 2.9BSD, but at the time, I only had one RL02 drive. > The Ultrix-11 RL driver does fancy things with overlapped seeks that I'm sure > works on real hardware but on the DQ614, not so much. Ah... I can see that. It wouldn't surprise me if the DQ614 got most of its development and testing with RT-11 in mind, and possibly some RSX-11. I remember that the DEC RL controller (at least for PDP-11, not as sure about the RL8A) did support some pretty handy things for a multi-user OS, like overlapping seek, but I think in all the years I worked with DEC gear, only a few machines had multiple RL drives. Mostly I saw them as data transfer devices or for primary storage on small (single-user) systems. We did have one larger system, an 11/24 with four RL02, running RSTS/E and whatever we were using for accounting software. I didn't work on the machine myself except to physically disconnect and pack and move it from one site to another when we consolidated our operations back into one building. -ethan
