16 Nov
2021
16 Nov
'21
7:32 p.m.
On 2021-11-16 19:20, Dave McGuire wrote:
? 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.
An extra RL02 is almost invaluable. We do crash dumps on it, we run
diagnostics from it, we can easily move files to/from it on the RL02 and
so on...
And the tape drive is nice for backups, software installations...
Although nowadays with virtual tapes, the tape drive isn't needed that
often. A long time since the last RSX release came around. :-)
TU81 is 1600/6250. So from time to time we have hooked up a TU77 as
well. But the status of those drives are a bit unknown today.
But occasionally we also get requests for media conversions... For that
purpose we also did plan for quite a while to hook up an RK11 and RK611
to Magica. But now I think we'll have to scrap that plan.
? 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.
I would like to test something with SCSI one of these days.
I have SCSI on my 11/93, and CPU wise the difference isn't that big
compared to Magica, but pure disk I/O operations difference is huge.
Sure, Qbus is a bit better than Unibus here as well...
But it just feels like seek times is playing a big part.
Plugging something into the RH70 slots is definitely tempting...
The one other big thing on the wish list for any 11/70 would be a
PEP-70/HC-70 combo...
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
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!
It's fairly simple, if a bit stupid.
You can see an older version of the Datatrieve code inside the C file,
but a more up to date version is in the CMD file.
The C code also make use of a C library to access the DTR call
interface, making it a bit easier to use than the standard interface DEC
defined.
??
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. ?? 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. ? 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.
I sortof don't like the 11/34 that much. Boring front panel (if you even
have one), and limited capabilities. :-)
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.