16 Nov
2021
16 Nov
'21
7:20 p.m.
On 11/16/21 1:05 PM, Johnny Billquist wrote:
Very nice, I will look at it. I've been wanting to learn Datatrieve
programming. Thanks for the source!
Yes, I removed the BA11-K expansion chassis when I got that system
many years ago. The system was going into my house, years before I ever
knew I would be able to finally realize my dream of opening a big-iron
museum, and the only thing in the expansion chassis was a DH11 and a few
DZ11s, and that chassis was the only thing in that extra rack. So,
needing to reduce its size and power consumption for a home environment,
I removed that chassis and rack from the configuration. That was about
twenty years ago. The DL11-W, UDA50, and DELUA are currently the only
Unibus peripherals on FANG.
Now, with the machine at the museum with a lot more space and power,
we're in the process of putting the expansion chassis back into the
system, but with different contents.
Before we got the RA73s, I was running an Emulex UC17 and a 200MB
SCSI drive on that system. I didn't do any tests either, but I think
the bottleneck was the Unibus; the UDA50+RA73 doesn't really feel any
different.
That UC17 is now on my personal PDP-11/34 at home, connected to two
Bernoulli 44MB drives. I make disk images under simh, and dd(1) them to
cartridges to run on it. That 11/34 has no network interface, so it's
not on HECnet, but I do run it occasionally, for soul-healing purposes.
I may try to network it at some point.
?? Speaking of
ddb, does it do a DTR query across the network to
access the data?? Or something else?
Yes it does.
Sources are on MIM. See
MIM::HECNET:DDB.C
and
MIM::HECNET:DDBDTR.CMD
(Yes, DDB itself is written in C.) ?? It sounds
like MAGICA is much bigger.? We don't yet have a Unibus
expansion chassis connected to FANG, so we have limited Unibus slots.
There's an RL02 and an RX02 in its rack, but no place for their
controllers to live.
What? You only have the four slots in the CPU backplane? That's a rather
unusal and limited 11/70 setup. I think it was pretty much standard that you had at
least one BA11 box
in any 11/70.
Yes, I assume so; that's the only way I've ever seen them in the field.
?? We also
have an Emulex SC72 disk controller (actually a few of
them), which is a board set that plugs into RH70 slots and implements
an SMD interface.? We have a Fuji Eagle prepped and ready to go onto
that, but we still need to cable it up, format it, etc.? I expect that
to be much, much faster than the UDA50+RA73.? Hopefully we'll get to
that sometime this winter.
That could potentially be much faster, yes.
I haven't done any tests, but I suspect even some SCSI on the 11/70 and
some modern disk would be a big improvement. I think seek times on the
RA73 isn't that great. But the Unibus on the 11/70 is also known as possibly
the slowest Unibus
around.
Yes, that's why we'd like to move our mass storage away from that, if
we can make it all work.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA