17 Oct
2013
17 Oct
'13
9:48 p.m.
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.
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.
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?
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.
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.