[HECnet] disk loading success

[Dave McGuire]

  [Please forgive the cross-post...I don't think all of the "social"
people on the HECnet list are actually on the DECtec list (yet).   I
believe this to be a general-interest post.]

  I just did something cool.   I've long been in need of a more
convenient way of loading up system disks for real PDP-11 and VAX
systems, and I've finally come up with one.   It's dead simple.
Initially I had wanted to set up a MicroVAX running NetBSD for stuff
like this, but NetBSD/vax has had a lot of problems in more recent
releases, and is becoming rather slow and bloated. (I never thought I'd
see myself say that about NetBSD...I've been running it since v0.9!)

  Yesterday I fired up a simh PDP-11 instance, installed RSTS/E v10.1 on
an RA90-sized disk image, and used Linux' DECnet support to copy it over
to my VAX-7000.   The VAX-7000 has an HSJ50-based disk subsystem, but it
also has a pair of KDM70 SDI controllers.   It is running VMS v7.3.

  I plugged an RA90 into the VAX-7000, did a mount/foreign on it, and
copied the disk image over to the raw device.   I started up a simh
PDP-11 on the VAX-7000, attached device rq0 to the raw physical RA90
drive, and booted it.   It booted and ran normally!

  Then, armed with confidence from that success, I dismounted and
unplugged the RA90 from the VAX-7000 and plugged it into a PDP-11/44
(2MB, FPP, CIS, UDA50) and booted it.   That worked too! =)

  (Now of course I could do the same with a Qbus PDP-11, with a KDA50
SDI controller.)

  My first desire was to do the actual RSTS/E install under simh on the
VAX-7000 directly to the raw device, but that crashed for reasons
unknown.   Mark Pizzolato told me that it was unlikely to work, so I may
not investigate that any further.

  Tonight, I will likely put together a VAX4000-700 in a BA440 chassis
with DSSI drives.   Into that I will put a KDA50 (I have an S-box KDA50
distribution panel) and use that in the role of the VAX-7000 for this
type of stuff in the future.

                                  -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA