18 Oct
2013
18 Oct
'13
7:52 p.m.
On 2013-10-18 00:48, Jerome H. Fine wrote:
If you don't have a PDP-11 (or at least a Qbus PDP-11),
then this is definitely a good start.
I do have an 11/83 that I still haven't gotten up and running yet. I'd
love to find a pedestal (plastic 'wrapper') for it, as mine came out of
a rack at one point in it's life.
This VT103 makes my second PDP-11.
What is your goal? Is this primarily a hardware project and what
operating system you run is not important? Or do you have specific
software goals?
As I have an 11/83, I don't have a particular goal in mind... but it
would be nice to collect the parts necessary to juice it up a bit so
there are more options.
An excellent start. The LSI-11 does not support an MMU,
so ONLY UnMapped Monitors can be used. For RT-11,
that means RT11SJ or RT11FB. Since you have 48 KB
of memory (the maximum for RT11FB is 56 KB in any case
unless you use a 4 KB IOPAGE), RT11FB will run very well.
I suggest you check the board number!!!!!!! If M7264-EB is
correct, then according to the field guide from Megan Gentry,
you actually have a KD11 or an LSI-11. BE CAREFUL!!
A field guide I found on line says it is a KD11-F, and it has the
socket filled with the right part number, so it has the KEV11 option.
I suggest that you attempt to upgrade to at least V05.03 of RT-11
since the features in that version are much better than in V04.00
of RT-11. If that is possible, upgrading all the way to the most
recent
version of RT-11 should also be possible and with 48 KB of memory,
RT11FB will run well. You also have the advantage of current manuals
which are available on bitsavers.
My first step for the 103 will be to clean it up in and out, get it
operating, and preserve the floppies and tapes (I have at least Basic
and Fortran I believe).
Then learning and doing some stuff with it for fun once I know the data
is preserved.
As for archiving the RX02 floppies, it appears that Kryoflux supports
RX02 media... I just need an 8" floppy drive and adapter.
(and a Kryoflux). Still trying to find out if there are other options
for reading/writing these off of the VT103 with solutions like the
Kryoflux.
With the lack of support for an MMU, you don't have much
choice.
Hence thinking towards something more powerful inside it towards the
future. I like the idea of getting it self contained with a hard drive
(ideal would be something based on compact flash, SD, etc), powerful
enough to run an old BSD, RSTS/E (if possible), etc. Not sure if I can
get enough memory/cpu/peripherals into it (slots and power
restrictions). Having storage, memory, and a network card would be
cool. How much memory does PDP-11 BSD require ? RSTS/E ? Can it be
done with an 11/23 in a VT103 with the backplane modified for 22 bits ?
Using an emulator would be a fast way to do it.
The piece you don't really learn with an emulator is the hardware,
buses, interfaces, construction, etc....
Now emulating a DEC-10 is the way I'll have to go in that department
(short of rescuing a TOAD-1 (probably have better luck winning the
Power-Ball Lottery !). Not sure if I'd ever get lucky enough to own a
10 small enough to want to deal with running physically (though that
would be awesome !)
Likewise!!!!!! I would also suggest that you don't run
for hours on end. There is a definite limit to the 5 V
supply and with the age of the VT103, the internal
power supply might be hard pressed. I don't really
know, maybe Tony can comment on how well a DEC
power supply ages????????????
My biggest concern are the capacitors.... the questions of:
1. are they doing their job ?
2. are they going to blow ?
3. could they take anything out downstream (cpu, etc) ?
are what come to mind.
Wonder if the VT103 used standard voltages so that if more power was
needed a more modern rack mount PC power supply could be wedged in to
provide the extra kick ?
Any changes I make (other than going to 22 bit backplane) would have to
be reversible.
I have no idea if it is in the configuration DEC sold it (is there any
way to know) ?
It was used at University of Lowell years ago for computer classes (as
I was told it was donated by Digital). (I did not get it from the
school, but I did get it from someone who had been involved in the day
setting these up for the school).
ALMOST ALWAYS based on what I have heard.
And is there any replacement capstan that someone has come up with ?
If you want to save the contents and the TU-58 drives
are OK now, do it ASAP.
Need to get it all going first, but preserving the media is one thing I
want to do.
Rather than an RX02 emulator, maybe the TU-58 emulator.
These emulators support VERY LARGE emulated TU-58
media and you could copy the 988 blocks (about 1/2 MB)
to your emulated TU-58, then save the file to the hard drive.
That is an interesting idea. Although something like a Kryoflux would
be good as the media can be recreated w/o a DEC system w/RX02.
If you can upgrade to at least a PDP-11/23 and a CQD-220TM, then
a 3 1/2" 50 pin SCSI drive can use the power directly from the VT103.
You can solder the wires to the board while also distributes the
power to
the TU-58 and solder the pins for a power plug for the 3 1/2" hard
drive.
At one point, I upgraded a number of VT103 systems to use an ST412
(10 MG hard disk drive) on a 3rd party MSCP controller and I mounted
the ST412 (5 1/4" hard drive) just below the tube. There was just
enough
power for everything with that 3rd party MFM controller. The RQDX2
would have used too much power and, in any case, does not have a boot
ROM which was needed with the M8186.
If you upgrade from an 18 bit backplane to a 22 bit
backplane, I don't think removing the extra wires would
be considered to bring it back to original. Since everyone
has their own definition, you decide. My personal preference
to have more than 256 KB of memory would outweigh
any concern.
Making the backplane 22 bit, while not being original, would be easily
undone (as long as nothing was on those 4 lines already which requird
removal), plus even with the 4 extra bits wired, an 18 bit setup would
still work in it.
Ethan Dicks
wrote:
On Wed,
Oct 16, 2013 at 11:28 PM, rescue <rescue at hawkmountain.net>
wrote:
I made a trek over the weekend to collect a VT103
with RX02 drive
unit.
Nice.
With it
came around 35+ 8" disks with stuff on them, and a dozen or
so
DECtape II tapes for the dual dectape II drives in the VT103.
Cool.
I have not tried powering on either unit yet.
Inventory of the boards in the VT103 are:
M7264-EB KDF11-F with KEV-11 with onboard 4KW MOS RAM
M8047-CA 16KW RAM
M8044-BB 8KW MOS RAM
M8028
M8029 RX02 flopppy disk controller (18 bit DMA only)
Seems like a good setup.
BDAL18-21 are used VERY differently for the LSI-11
than for the PDP-11/23, etc. Before you use a different CPU
or upgrade to a 22 bit backplane, find out from someone who
knows what, if anything, needs to be done. OTHERWISE,
there may be a release of magic smoke (the euphemism on this
list for a fatal hardware burnup!!!!!!!!!!!). On your backplane,
there may be power on some or all of BDAL18-21. Since
all of the VT103 terminals I have ever seen used at least an
M8186 (PDP-11/23), BDAL18-21 were all UNUSED.
Thankfully I haven't release much magic smoke of my own accord. I did
have 2 Sun 600MP boards let go the magic smoke on a surface mount
capacitor on each. I scavenged a couple of the same size/value off of
some PC mobo in my junk bin. Worked great. Not sure of those are
tantalum... but working with arcade games I've grown to not like
tantalums.... when your 12" from a monitor/board working on it and one
goes like a firecracker, its unsettling !
I have a
set of floppies with dot matrix'd lables 1/4 through 4/4
for RT 4.0
"patched". Not sure if these are original DEC. They have DEC part
numbers/etc on them, but nothing that really indicates they are DEC
(no DEC
branding/etc). Any idea of these are original ?
All of my original DEC floppies had typewritten text on labels with
blue DEC
edges/markings. It sounds likely that these are copies, possibly of
original
DEC distro diskettes.
Where are you located? If you are restricted to RX02 floppy media,
then someone might be able to copy the needed files.
I'm in Sharon, MA.
Given the CPU and storage, I'd assume RT would be
this boxes current
limit,
correct ?
Yes. 28KW is plenty for RT-11. There might be something else you
could
run in that (like RSX-11/S?) but not much.
>Are 2
8" floppy drives enough to make a sysgen'd RT with software
> and space
>to do stuff with ?
>
>
YES!! But is would be slow and cumbersome with just the
dual RX02. I recommend you stick with DEC distributions
for now until you obtain a hard disk drive. If you really need
to perform a SYSGEN, do so under Ersatz-11 with an
emulated 32 MB (or larger) emulated hard drive, then transfer
all of the files back to your system.
What would be your goal in performing a SYSGEN?
The point of the sysgen would be... experience, and tuning the OS to
the specific hardware.
Sure. It'll be slow to compile FORTRAN, but
fine for BASIC or
MACRO-11.
I suggest that FORTRAN IV will be OK as well. Just don't
expect anything to be very fast. If you want FAST, then use
the Ersatz-11 emulator. I estimate that a current 3 GHz Intel
CPU will be about 500 to 1000 times faster (based on being
able to run RT-11 more than 100 times as fast as a PDP-11/93). Before
powering up for the first time, anything I should be aware of
that
would be likely weak with the VT103 after years of sitting idle
(attic) ?
(i.e. caps in the power supply are likely to pop)
I will defer this to others. Do you know how recently this was
powered up?
How are the DECtape II drives ? Do the capstans tend
to turn to goo
?
Yes.
They
look OK visually, though I have not touched them. Any good way to
confirm
if they'll hold up or break down before they eat a tape ?
I give mine a squeeze. If they deform like jelly beans and leave a
black
stain on your fingers, they are toast. If they don't now, they wiill
at
some point.
How best
to preserve images of the 8" disks ? I understand there
are
parallel port RX02 emulators for the system, but nothing that I
found for
hooking up the RX02 drive unit to a PC for imaging. I've also read
that the
RX02 used a percular format (MFM sector data with FM headers as I
recall).
Will things like the Disc Ferret archive images if I had a more
modern 8"
floppy drive to use with it ? Suggestions ? Obviously if I get the
system
working and I had another M8029 (which I don't), I could hook up a
RX02
emulator and duplicate discs from real ones to the emulator. Is
that the
only viable option ?
I would like to know a good way to do it with a low-memory machine.
One can use vtserver on a machine with enough RAM to run 2BSD (it's
a standalone disk image read/write tool that can be used to put UNIX
on blank hard disks), but AFAIK, the vtserver client requires more
than 28KW of RAM.
One way I've done in the past uses hardware you didn't say you had.
You can put 8" floppies on a MicroVAX and use EXCHANGE or
BACKUP/PHYSICAL.
Just a suggestion, I have never used the TU-58 emulator myself.
You can use any M8186 or M8189 (PDP-11/23 CPUs) or
M8192 or M8190 (J11 CPUs) in either an 18 OR 22 bit
backplane. What I do NOT remember is what the 18 bit
backplane requires for the M7264 to run. I seem to remember
that the PDP-11/03 required power on lines BDAL18-21,
so as I suggested (WARNED EMPHATICALLY ABOVE),
CHECK WITH SOMEONE WHO KNOWS WHAT IS
REQUIRED!!!!!!!!!!!!!
If your BDAL18-21 lines are unused at the moment (or you can
remove what has been added to them), then I have upgraded
my VT103 which I received with an M8186 (PDP-11/23) with
256 KB of memory. Other than identifying the exact points to
solder the extra wires (you will need lead based solder since this
is a VERY OLD backplane), it is very easy to use insulated wire
wrap wire (either 28 or 30 is probably OK) and strip the
insulation ONLY where the wire needs to be soldered to the
backplane. If you have a 4 x 4 backplane which allows 8 dual
boards, each wire needs 8 solder points. Start by stripping the
insulation as far back as possible (I suggest about 2 ", but maybe
Tony can elaborate) from the end if the wire and solder the first
point. Then cut the insulation (WITHOUT CUTTING THE WIRE)
for the exact distance needed to the second solder point and squeeze
the insulation as far away from the second solder point on the wire
as possible. Solder and repeat 6 more times with the first wire.
If you hold the wire carefully just beyond the solder point and very
gently press the bare wire to the next solder point (I suggest - Tony
please comment - with flux already on the bare wire), then with the
other hand heat the bare wire and below it the solder point until the
solder melts, that could be quite sufficient if you immediately
remove
the heat and allow the joint to harden as you prevent any movement
of the wire relative to the solder joint. It is probably best if you
completely remove the backplane before you start.
If you mean a CQD-220M or CQD-220TM in a 22 bit backplane,
I agree. I have not ever placed a CQD-220TM in an 18 bit backplane
or with a PDP-11/03. Since a CQD-220TM is probably still fairly
expansive, a PDP-11/23 with at least 1 MB of memory is probably
a reasonable companion for a CQD-220TM.
Yes, I was referring to the CQD-220M. I have one now for my 11/83.
And
lastly, towards the future, I understand one can add the 4
missing bits
on the backplane to go from 18 bits to 22 bits, then an 11/23 cpu
can be
used in it.
Yes.
Is this
the only cpu board upgrade option viable in an VT103 ?
With that, I'd assume RSTS/E, TSX, RSX, RT, and old Unix would be
options ?
Perhaps someone here who has done it could comment, but I'd
want to check the current draw against what the VT103 PSU
can provide. You might be able to get away with a KDJ-11 board
of some kind. With more memory, those other operating
systems become viable. 2BSD wants at least 1MB, ISTR,
but 4MB would be grand (if the PSU could handle it). TSX-11
probably runs in 256MB or less, but it's been years and I"m
not sure what the requrements are. Older versions of RSX-11
run in 256KB. A hard disk of some kind becomes
your next sticking point. You'll have to power the disk
externally, but even an RLV12 and a an RL02 or two
is a huge step up from dual RX02 (I made my living for
a year in the late 1980s with an 11/23 and a single RL01
running RT-11 v5.x, so you don't need 400MB to do
interesting things - even 10MB or 30MB is a lot).
What would
be the suggested hard drive options ? Will CQD-22 SCSI
work on
the existing CPU ? Will it work with a larger CPU with an upgraded
bus
within the VT103 ?
I think both of those are true. I haven't tried running a Q22 disk
interface in a Q18 backplane, so
I I'd
like to consider some sort of SCSI->ATA->flash
solution for low power and put it inside the VT103 for a self
contained
approach. The mounts are not standard, otherwise ZIP drives or JAZ
drives
in place of the DECtape IIs would offer immense storage and easy
switchover
to other 11 OSes.
A SCSI interface and a ZIP or JAZ drive should be fine, for as
long as your media lasts.
One thing to watch for is your operating system of choice must
support MSCP disk to use a SCSI controller. This means RT-11 v5
not v4, AFAIK, but others on this list probably know detailed
specifics off the top of their head. 2.9BSD does not support
MSCP (but can be patched) and 2.11BSD does not support
processors that don't have split I&D (like your CPU or the KDF-11
in an 11/23 - you have to move up to a KDJ-11 to run 2.11BSD
on a Qbus box)
Looking to
understand this box more, how to bring it back to
operation, and
what I can do with it as is, and improve it a bit towards the future
(no
cutting/drilling.... any upgrades have to be able to be removed to
bring it
back to original.
Get it up and running RT-11 from RX02 and see about those upgrades
you were thinking about. Perhaps someone who has loaded up
a VT103 with newer boards can tell you what does work. I have
a VT103 myself but haven't tried maxing it out. I have other Qbus
boxes I can do that on.
Since the very first PDP-11/23 that I owned was a
VT103, the opportunity to upgrade was taken VERY
seriously and done as soon as I could purchase the
required parts. After I received a BA23 box, I stopped
using the VT103, but it remains a very important (and
still very much appreciated) member of my PDP-11 systems.
Jerome Fine
I appreciate everyone's knowledge and input here on this.
I've got a long list of systems to get to including Sun 1/100U, Sun
2/120, Sun 3/450, Sun 486i, Altos 886, OKIstation 7300, Symetrix 375,
Amiga 1200HD, PDP-11/83, VT103, Professional 380, Rainbow, Spare Time
Gizmos SBC6120, SGI Indigo, and more.....
Big on the list to get someday is a PDP-8/E or PDP-8/F. (I have a
VT-52 to use on one, just not the 8)
Years ago I had a mint VT-78/WA with an RX01 and RX02. These looked
like new pieces. Unfortunately that was the early 90s and I thought
even if I could have found software I was limited to a glorified word
processor.... I had no idea what lurked under the hood was a PDP-8. It
was consuming space in my father's barn, and he hounded me till I gave
in... all three pieces got dumpstered :-(. All I have left (somewhere)
is one floppy cable for connecting the VT-78WA to an RX01 or RX02, and
some module that screwed on the back of the system. When I grabbed it,
I thought it was a VT-52... and I was looking for a terminal....
whenever I think of that system and what I lost when I caved, I cringe.
I'm happy to have an RX02 again !
I'll close now that I've drifted off the topic of the VT103 :-)
Thanks everyone !
-- Curt