25 Jan
2011
25 Jan
'11
9:23 p.m.
I am reassembling a PDP-11/44 from parts for the Rhode Island Computer
Museum. I would like to try an RL01 or RL02 drive on the system, but
we don't have another RL02 controller.
Do any of you have a M7762 RL11 disk controller board that you could
donate or sell inexpensively for this project?
The RA81s won't spin up, so I suspect that I need to replace the
starting capacitors.
Do any of you know where to get replacement starting capacitors for
the RA80 or RA81 drives?
Details on the project are here:
https://sites.google.com/site/ricmwarehouse/Home/equipment/dec-pdp-1144
--
Michael Thompson
26 Jan
26 Jan
10:11 a.m.
On Tue, Jan 25, 2011 at 9:23 PM, Michael Thompson
<michael.99.thompson at gmail.com> wrote:
I am reassembling a PDP-11/44 from parts for the Rhode
Island Computer...
The RA81s won't spin up, so I suspect that I need to replace the
starting capacitors.
I read through the blog - if the motors start spinning as you describe
(I envision you mean for a few seconds; please correct me if this is
wrong) _then_ the drive stops spinning, I doubt it's the capacitors.
If the motors _don't_ start moving when you put the drive online, then
that is one component to examine.
RA81s were at one point, exceedingly susceptible to HDA failure. I
don't recall the specific ECO levels, but some version after "E" used
a different glue than its predecessors leading to particulate
contamination leading to catastrophic failure. ISTR looking for "H2"
or "K2" drives after that disaster.
RA81 drives have a DB25 inside. You can plug a terminal in and run
on-board diagnostics and monitor operations. You can run with the lid
up or lid down (snaking a ribbon cable out of the drive). The molex
connector next to the data connector is to power a small hand-held LED
terminal (I saw one once, used with a high voltage chassis for
particle physics, but the terminal was the same).
Try plugging in a working VT220 and letting the drive tell you what it
thinks is going on. You might find that it's starting to spin up then
not liking what it sees and spinning down.
Oh... just a detail - you mention locked heads - you _did_ pull the
cord to retension the drive belt, right? (for safe transport, the
RA81 has you locking the heads _and_ disengaging the motor from the
HDA by removing belt tension). If you didn't do this step, what I
think may happen is the onboard processor will start to spin the
motor, sense no rotation from the HDA, then spin the motor down and
emit a fault code. Maybe this is what you are seeing?
Reading through your blog, I don't think you will have success with
booting 2.11BSD on your 11/44 with a TU81+ unless you have install
media that knows about that tape controller. The 2.9BSD tapes I have
require an "MS" device (older OSes might or might not require an "MT"
device). Back in the day, there were several incompatible tape
controller types, with different boot ROMs, and your install media had
to match your controller and ROMs (or you had to toggle in the
bootstrap). You can install 2.11BSD using vtserver and a virtual tape
drive though. Also, if you do get real 2.11BSD install tapes, you'd
probably want to be looking for a TU80 and, IIRC, an M7454 controller
card.
-ethan
4:45 p.m.
Hi Michael,
I have the RL11 (M7762) for $ 60. If you need cables, I should have them,
but need a few for myself and a list member who is getting an RL8-A from me.
Domestic shipping should be around $10.
Thanks, Paul
On Tue, Jan 25, 2011 at 8:23 PM, Michael Thompson <
michael.99.thompson at gmail.com> wrote:
I am reassembling a PDP-11/44 from parts for the Rhode
Island Computer
Museum. I would like to try an RL01 or RL02 drive on the system, but
we don't have another RL02 controller.
Do any of you have a M7762 RL11 disk controller board that you could
donate or sell inexpensively for this project?
The RA81s won't spin up, so I suspect that I need to replace the
starting capacitors.
Do any of you know where to get replacement starting capacitors for
the RA80 or RA81 drives?
Details on the project are here:
https://sites.google.com/site/ricmwarehouse/Home/equipment/dec-pdp-1144
--
Michael Thompson
5:25 p.m.
New subject: Need RK8E Controller [Was: Need RL02 Controller for PDP-11/44 Restoration]
All this talk of folks needing an RL0x controller for a Unibus machine
got me to thinking - I have a PDP 8/e in nice shape, and a few known
good RK05 drives, but no RK8E controller boardset. It gets tiring
running the machine off of paper take or RX01 floppies.
Anyone out there have one (or Plessey or other equivalents) that they
might be willing to sell? I have all of the cables needed, including
the paddle cards that plug into the Omnibus to connect up the drives,
just need the three board set in known operational condition.
Rick Bensene
27 Jan
27 Jan
4:46 a.m.
New subject: Need RK8E Controller [Was: Need RL02 Controller for PDP-11/44 Restoration]
On Wed, 26 Jan 2011, Rick Bensene wrote:
Anyone out there have one (or Plessey or other
equivalents) that they
might be willing to sell? I have all of the cables needed, including
the paddle cards that plug into the Omnibus to connect up the drives,
just need the three board set in known operational condition.
Ehm, there are no paddle cards in the Omnibus... The controller is a three
board set which also includes the one-cycle data break interface. The
drive cables directly plug into one of the controller boards. Or do you
mean the "Unibus" (BC11) cables to connect one drive to the next one?
You may ask Philipp Hachtmann for a controller, he may be able to help
you.
Christian
3:22 p.m.
New subject: Need RK8E Controller [Was: Need RL02 Controller for PDP-11/44
All this talk of folks needing an RL0x controller for a Unibus machine
got me to thinking - I have a PDP 8/e in nice shape, and a few known
good RK05 drives, but no RK8E controller boardset. It gets tiring
running the machine off of paper take or RX01 floppies. =20
Youdo realise, I assupe, that an RK05 used with a PDP8 needs 16 sector
packs, which are a lot harder to find than the 12 sector ones used with
PDP11s. There are har dectored packs, the number of sectors is determined
by the number of slits in a ring on the hub. Good luck if you want to try
re-making that ;-)
Anyone out there have one (or Plessey or other equivalents) that they
might be willing to sell? I have all of the cables needed, including
the paddle cards that plug into the Omnibus to connect up the drives,
just need the three board set in known operational condition.
I am a little confused here...
The I/O connecotrs on the RK05 are the normal DEC connector blocks, a
dual-height slot, actualy, You interconnect multiple drives using Unibus
cables amnd put na M930 terminator (original Unibus terminator) in the
last drive.
On a PDP8/e, the drives are not dirrectly connected ot the Omnibus
backplane/ There's a cable consisting of 2 ribbon cables with BERG
connecotrs at one end and a dual-height DEC board at the otther. The
board plugs into the first drive, the BERGs plug into one of the boards o
nthe RK8e. IIRC, there are actually several versions of that cables with
different (if any) circuitry on the PCB, but I think it's possible to
convert one to another.
Is that the cable you have?
-tony
11:28 p.m.
New subject: Need RK8E Controller [Was: Need RL02 Controller for PDP-11/44
Tony (understandably so) wrote that he was confused by my statement
about paddle boards for the RK8E.
Sorry for the confusion. I was mentally confusing the RK controller for
the Unibus PDP 11 with the RK8E. I do have the correct cables for the
RK8E/RK05.
I also have a ton (OK, maybe tens of pounds) of 16-sector packs for the
RK05/RK8E.
Rick Bensene
31 Jan
31 Jan
7:48 a.m.
New subject: RSTS V7.0 source in any form?
I was searching the web for any sort of RSTS source and I could not find
any.
Does anyone have sources (in any form) for RSTS V7.0?
I'd like to look a the first part of the boot, basically the code which runs
right after the boot sector (which I think is init.sys)
Was this often distributed as hard copy printouts or microfiche?
If so, anyone have any scans?
thanks
-brad
4921
days inactive
4926
days old
7 comments
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participants (7)
-
ard＠p850ug1.demon.co.uk -
brad＠heeltoe.com -
cc＠informatik.uni-stuttgart.de -
ethan.dicks＠gmail.com -
michael.99.thompson＠gmail.com -
rickb＠bensene.com -
useddec＠gmail.com