On Fri, Sep 17, 2021 at 9:32 AM Clem Cole wrote: > FYI: The KS11 MMU for the 11/20 was built by CSS and was not on the > product list as it were. To my knowledge, no hardware or prints of it > survive. I've been told it was much more similar to the MMU in the KA10 > than the scheme eventually done for the 11/45/55/70 and the 11/40 class > systems - but I think Noel has done more investigation than I have. So if > others have more info, please chime in. > > As Warner points out the oldest code base we have is Fifth Edition. > I'm not sure if the KS11 code is still there. I did not think so. I > thought it ran on 11/40 and 11/45. > > The V1 work was for a PDP-7 and is before the first 11/20 was secured. > The point is that I think there is a hole in the the SW we have. > V0 was for the pdp-7/pdp-9. V1 was the first port to the 11/20. V2 still supports the 11/20, but V3 and V4 move heavily to the 11/40s and 11/45s. We have printouts for V0. And the kernel for V1 with bits and pieces in the V2 to V3 timeframe that folded into the Unix-Jun72 efforts. Warner > As for RK03 vs. RK05 -- *I think I can help a little*. RK02/RK03 used > an RK-11C. I'm fairly sure that the RK05, used the RK11-D controller. > The '72 peripherals' handbook describes the former and the '76 the later. > But if you believe the handbook, both supported 203 cylinders and 2.45M > bytes/disk with 512 byte sectors. The difference seems to have been in > drive performance. > > On Fri, Sep 17, 2021 at 10:34 AM Warner Losh wrote: > >> >> >> On Fri, Sep 17, 2021 at 8:10 AM Roland via TUHS >> wrote: >> >>> Hello Unix fanatics, >>> >>> I have a PDP11/20 and I would love to run an early Unix version on it. >>> I've been working on the hardware for a while and I'm getting more and more >>> of the pieces back online again. The configuration will be two RK05 hard >>> disks, TU56H tape, PC11 paper tape reader/puncher and a RX01 floppy drive. >>> Unfortunately I don't have a MMU or paging option. But it seems that the >>> earliest versions of Unix do not need the extra memory. >>> >>> Does anyone have RK05 disk images for these early Unix versions? That >>> would be a great help. Otherwise it would be great to have some input about >>> how to create a bootable Unix pack for this machine. >>> >> >> V5 is the earliest Unix we have contemporary images from. We have >> fragments from everything else earlier, including files scavenged/recovered >> from early DECtapes and some code recovered from kernel listings from a >> Unix course that was put together by Bell Labs... >> >> The Unix 1972 project that some TUHS members did. I think it's in the >> TUHS distribution archive, but also on github. I think Warren Toomey's repo >> is the canonical one https://github.com/DoctorWkt/unix-jun72 but >> https://github.com/c3x04/Unix-1st-Edition-jun72 has a couple of newer >> fixes for a docker file to contain the simh simulator. I'm unsure what >> hardware that's supported, though. The machine file suggests: >> >> rk03/rk11 177400 disk RK >> dc11 174000 tty? (not supp?) >> tc11/tu56 177340 dec tape DTn (not showing up in simh?) >> rf11/rs11 177460 fixed head disk RF >> kw11-l 177546 clock CLK >> pc11 177550 paper tape PTR/PTP >> asr-33 177560 tty? TTI, TTO >> >> which has an RK03, not sure how close that is to an RK05, so some tweaks >> may be needed. >> >> Warner >> >> >>> A bit about the hardware restoring is on the vcfed forum: >>> >>> https://www.vcfed.org/forum/forum/genres/dec/78961-rk05-disk-drive-versions >>> https://www.vcfed.org/forum/forum/genres/dec/80723-pdp11-20-restoring >>> >>> Booting RT11 from RK05 >>> https://youtu.be/k0tiUcRBPQA >>> TU56H tape drive back online >>> https://youtu.be/_ZJK3QP9gRA >>> >>> Thanks in advance! >>> Roland Huisman >>> >>> >>> >>