5 Oct
2007
5 Oct
'07
6:09 p.m.
[Sorry for the double post...having trouble with my mailer
line-wrapping]
The gods smiled upon me, and I was chosen to rescue the DEC
VAX 11/750 that Richard alerted us too about a month ago.
Yesterday I went up to collect it. I think most of us,
during a pickup, are mindful of just getting the load
onboard and away, and it was the same way for me with
this pickup. Besides, the unit was literally stuffed so
tightly into the front corner of their storage that there
was no way to examine the innards at that location. A few
images can be found at:
http://www.rogerwilco.org/VAX11-750
Once back on homebase, I finally got a chance to open up the
unit. To my horror (it is October, after all), I find just
a single board installed in the CPU backplane, and one loose
q-bus board! The first is a System Industries 9700-6301
with the following significant chips: Signetics N8X60N, AMD
AM9128 (x2), Motorola MCM93L422PC (x4), TI SN74S181N, and
about a dozen TI 82S137s with little numbered stickers on
each. Otherwise it's loaded with TTL logic chips. There
are no headers or other connectors on board, just the
backplane fingers. I have no idea what this board is. I
openly admit that I'm a complete {non-uVAX | massbus |
unibus} novice. The second board is an MCD MLSI PC-11,
which I'm guessing may be some kind of dual parallel
interface. I'll have to do a little scouting on Bitsavers
and Manx to see if I can turn up anything useful.
Anyway, sadly, this box is not much more than an empty
carcass, without any brains. It clearly was sacrificed to
keep other systems alive. Still, I would dearly love to
populate the backplane(s) and light this baby up, but I
guessing I'll be hard pressed to find anyone with a whole
set of spares that I could somehow convince into letting
them go.
I don't want to lose an opportunity here, and I'm not saying
that I have my eye on the local metal recycler just yet, but
what am I going to do with an empty chassis?! Now, I should
say that the donor was extremely nice, and offered to pass
along anything related that eventually turns up as they dig
deeper into their massive pile (12' x 15' x 20', literally
boxes/cartons/PCs upon boxes/cartons/PCs), but I'm not sure
I should hope for much.
Am I foolish to ask? Anyone with a spare set of VAX 11/750
modules?
- Jared
6 Oct
6 Oct
1:28 a.m.
On 10/6/07, J Blaser <oldcpu2 at rogerwilco.org> wrote:
The gods smiled upon me, and I was chosen to rescue
the DEC
VAX 11/750 that Richard alerted us too about a month ago...
http://www.rogerwilco.org/VAX11-750
... To my horror (it is October, after all), I find just
a single board installed in the CPU backplane, and one loose
q-bus board!
That is unfortunate.
The first is a System Industries 9700-6301
with the following significant chips: Signetics N8X60N, AMD
AM9128 (x2), Motorola MCM93L422PC (x4), TI SN74S181N, and
about a dozen TI 82S137s with little numbered stickers on
each. Otherwise it's loaded with TTL logic chips. There
are no headers or other connectors on board, just the
backplane fingers. I have no idea what this board is. I
openly admit that I'm a complete {non-uVAX | massbus |
unibus} novice.
That looks to me (from appearance and the part number) to be the
11/750-specific SI-9900 interface. I have one in an 11/750 in my
quonset hut. SI made a number of host-specific interfaces (Qbus and
11/750, for certain, others likely)... this one fits in the same kind
of slot as a DEC RH-750 MASSBUS interface, but is not, itself,
specifically a MASSBUS card (there is at least one other board for
that slot include, an additional UNIBUS interface).
For the case of what you have there, you should also have a pair of
40-pin cables going off the backplane for that slot, out to an I/O
bulkhead header. There would then be a pair of (possibly shielded)
40-pin cables running off to a 5.25"-tall rackmount box marked "SI
9900". It should have at least one host board to receive the pair of
40-pin cables, then on the other side of the box, one or more disk
interfaces (there should be room for two or three of those). We had a
pair of SMD interfaces in ours, attached to 160MB and 450MB Fuji
disks, emulating a pair of RM03s and a "custom-sized" RM05,
respectively. The 450MB disk always caused us heartburn because we
had to patch the, IIRC, DBDRIVER.EXE to change the RM05 geometry,
every time we upgraded VMS. The 160MB drive emulated a pair of
RM03s/9762s, with no tweaking.
I did notice you have a cable hanging down for a UDA50... it's likely
that they had both SI disk _and_ Unibus-attachd SMD disks. That was a
common arrangement for a variety of reasons. You will also want to be
on the lookout for a DU boot ROM. The 11/750 didn't use the TU58 for
boot files as the 11/730 and 11/725 did. You just twisted the ROM
selector to the right device, then pressed reset/boot. the D ROM was
typically the TU58 boot (DDA0?) so you could boot tape-based
diagnostics.
The second board is an MCD MLSI PC-11,
which I'm guessing may be some kind of dual parallel
interface. I'll have to do a little scouting on Bitsavers
and Manx to see if I can turn up anything useful.
If you don't find anything, the board looks to me like a papertape
punch/reader interface. Try throwing that into your searches.
Anyway, sadly, this box is not much more than an
empty
carcass, without any brains.
Good luck on finding boards. They are out there, but I doubt they'd
be inexpensive from a dealer.
If you do find boards, you will have to match up the memory to your
memory controller. There are three flavors. The oldest only can talk
to 256KB boards (the same ones that work in an 11/730 or 11/70). You
can stuff a max of 2MB in there - enough for ancient UNIX or VMS, but
I wouldn't want to run VMS 4.0 or newer on that. The most common
version will support eight 1MB boards (same as used with an 11/730 or
11/725). The newest version supports a pair of 4MB boards and a six
1MB boards (14MB). I have never worked with that one, but it would be
something to look for.
The other thing to do, and I don't have the docs handy for this, is to
check your backplane in the memory area, to confirm what it's wired to
accept. I have 11/750 S/N BT0000354. It shipped with 512KB, then I
upgraded it to 8MB by adding the extra refresh/mux line and changing
the SID dipswitch (rather than paying DEC to do it). I presume an
additional wire is needed for the 14MB mod. I think you should be
able to put a lower-rev memory controller in a backplane designed for
a newer one, but you might need to update the SID switch to match what
the OS is expecting.
Don't let this worry you until you get enough boards to throw together
into a CPU... just get some memory - 1MB boards _should_ be safe -
then worry about which memory controller you find next. 256KB boards
shouldn't be expensive, I wouldn't think - since nobody wanted them
much after 1990. Everyone wanted 1MB boards for several varieties of
VAXen, so lots of those were produced, too. We even had a couple
3rd-party boards with a handful of 256Kbit DRAMs, but the DEC boards
(packed solid with 4164s) were the easiest to locate at surplus
dealers.
Now, I should
say that the donor was extremely nice, and offered to pass
along anything related that eventually turns up as they dig
deeper into their massive pile (12' x 15' x 20', literally
boxes/cartons/PCs upon boxes/cartons/PCs), but I'm not sure
I should hope for much.
Have them keep an eye out for that SI disk box - it's the other half
of the board you already have.
Am I foolish to ask? Anyone with a spare set of VAX
11/750
modules?
I have no spares, sorry. Just a couple of machines and lots of
experience crawling around inside them (at Software Results, I was our
own primary hardware maintenance resource from about 1990-1994).
-ethan
P.S. - don't forget to pick up a short length of 1/2 ID Tygon tubing
to rehab the TU58 roller. If you _do_ eventually have to scrap out
the machine, save the backplanes, PSUs and TU58 for other 11/750
owners. Best of luck on finding a boardset, though. The 11/750 is a
really neat beast. It would be good to see you getting it going.
11:33 a.m.
At 10:28 AM +0200 10/6/07, Ethan Dicks wrote:
On 10/6/07, J Blaser <oldcpu2 at rogerwilco.org>
wrote:
Not even looking at the pictures that was what I figured it was.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
The second board is an MCD MLSI PC-11,
which I'm guessing may be some kind of dual parallel
interface. I'll have to do a little scouting on Bitsavers
and Manx to see if I can turn up anything useful.
If you don't find anything, the board looks to me like a papertape
punch/reader interface. Try throwing that into your searches.
1:05 p.m.
Ethan Dicks wrote:
I'll give it a go and see what turns up.
Yes, they are. While making the pickup, we thought we saw another
cabinet just peeking out from under the huge lumpy pile, but it turned
out to be a telephone switch, I guess used as the in-house PBX by the
former owners of all of this stuff. Anyway, the donor is aware that
these big VAXen were coupled with external storage devices, and is
looking out for other cabs.
On 10/6/07, J Blaser <oldcpu2 at rogerwilco.org>
wrote:
Ah, okay, that's helpful. I'll keep that in mind as I do more
background research.
The first is a System Industries 9700-6301
with the following significant chips: Signetics N8X60N, AMD
That looks to me (from appearance and the part number) to be the
11/750-specific SI-9900 interface. I have one in an 11/750 in my
quonset hut. SI made a number of host-specific interfaces (Qbus and
For the case of what you have there, you should also
have a pair of
40-pin cables going off the backplane for that slot, out to an I/O
bulkhead header. There would then be a pair of (possibly shielded)
40-pin cables running off to a 5.25"-tall rackmount box marked "SI
9900". It should have at least one host board to receive the pair of
I'll check that, and see. So, is it normal that a lot of the
connections for this system come off the backplane, rather than headers
on the PCBs themselves? Hmmm..... No wonder the reverse side of the
backplane looks so hairy!
I did notice you have a cable hanging down for a
UDA50... it's likely
that they had both SI disk _and_ Unibus-attachd SMD disks. That was a
common arrangement for a variety of reasons. You will also want to be
Yes, looks like the SMD cabling is in there, but I haven't even gotten
so far as seeing where it might run to.
As it turns out, I _do_ already have an RA81 (and two Fujitsu Super
Eagles) that came along with a separate pickup of some qbus stuff a
couple of years ago. Maybe I now have a use for these drives, assuming
they are functional! ;-)
on the lookout for a DU boot ROM. The 11/750
didn't use the TU58 for
boot files as the 11/730 and 11/725 did. You just twisted the ROM
selector to the right device, then pressed reset/boot. the D ROM was
typically the TU58 boot (DDA0?) so you could boot tape-based
diagnostics.
Okay, good words, thanks for the heads-up on this. I am absolutely
novice with this system, so all suggestions and advice are very welcome!
The second
board is an MCD MLSI PC-11,
which I'm guessing may be some kind of dual parallel
interface. I'll have to do a little scouting on Bitsavers
and Manx to see if I can turn up anything useful.
If you don't find anything, the board looks to me like a papertape
punch/reader interface. Try throwing that into your searches.
Good luck on finding boards. They are out there, but
I doubt they'd
be inexpensive from a dealer.
I've been fortunate enough to already receive some helpful offers (you
guys know who you are!). It just depends on what specific pieces can
rationally be cut loose by their current owners.
The other thing to do, and I don't have the docs
handy for this, is to
check your backplane in the memory area, to confirm what it's wired to
Ooo, sounds like I've got some interesting self-education ahead of me!
:-) Wiring backplanes has definitely not been in my experience...yet! :-o
Don't let this worry you until you get enough
boards to throw together
into a CPU... just get some memory - 1MB boards _should_ be safe -
then worry about which memory controller you find next. 256KB boards
Great advice! Make sense to me.
say that the donor was extremely nice, and
offered to pass
along anything related that eventually turns up as they dig
deeper into their massive pile (12' x 15' x 20', literally
boxes/cartons/PCs upon boxes/cartons/PCs), but I'm not sure
I should hope for much.
Have them keep an eye out for that SI disk box - it's the other half
of the board you already have.
P.S. - don't forget to pick up a short length of
1/2 ID Tygon tubing
to rehab the TU58 roller.
Oh, yes, thanks for the reminder. Indeed there are about a half-dozen
carts floating around in the bottom of the cabinet. I haven't even
extracted them yet to see what they are. But I'll definitely want to
get an image of them, if I can, once the drive is revived. I wonder,
can the integrated TU58 be (temporarily) cabled to something like the
PDP-11/23+ that I have, so that I could image those carts first before
trying to use them in the VAX (eventually)? Is it just a standard
serial connection coming off of the drive, like the desktop TU58
subsystems, or is it something lower level? I guess I'll have to climb
in there and take a look, and scout the docs for more info.
Looks like this is going to be a somewhat lengthy revival, with lots of
things to consider, detail-wise.
If you _do_ eventually have to scrap out
the machine, save the backplanes, PSUs and TU58 for other 11/750
owners.
Actually, I just can't see myself scrapping the machine. It would be a
real shame to do that, so I'm going to do my best to get the backplane
repopulated, cobble some storage, and light it up!
Thanks for the advice and encouragement! Keep it coming!
- Jared
4:07 p.m.
Following up on previous postings...as I get myself educated a bit more
on this system...some questions for the 11/750 experts...
1. It appears that a 'complete' CPU boardset consists of, at a minimum,
the following:
- L0002 Data Path
- L0003 Memory interconnect
- L0004 Unibus interconnect
- either of L0005 CPU control store, or L0008 Program control store
- either of L0011, L0016, L0022 Memory controller (depending on memory
choice)
Is this correct? All other boards in the L-series are optional,
depending on other hardware options, right?
2. Is the L0005 or the L0008 preferred? Which one is easier to use with
VMS? With NetBSD? (Gee, a random thought just hit me...is there ULTRIX
for this beastie?)
3. The TU58 carts only hold 256KB, so they can't be used as a boot
device, I guess, but if I use the L0008 Program control store module, in
normal operations, does it get it's initial 'bootstrap' from the TU58,
or from the boot device?
4. With the L0004 Unibus interconnect in place, can I just use any (more
or less) Unibus module out there, for comm ports and storage?
Drinking from the fire-hose at first, here, and hopefully I can pose
more intelligent questions as we go along.
- Jared
7 Oct
7 Oct
12:57 p.m.
On Sat, 06 Oct 2007 17:07:03 -0600
J Blaser <oldcpu2 at rogerwilco.org> wrote:
2. Is the L0005 or the L0008 preferred? Which one is
easier to use
with VMS? With NetBSD? (Gee, a random thought just hit me...is
there ULTRIX for this beastie?)
There should be ULTRIX for the 11/750.
An other option is 4.3BSD-Tahoe. You can get it from TUHS or the CSRG
CDs. Once I instaled it on a MV II, that was upgraded to a MV III+ after
install. It was really fun to work with that old software. (And it felt
much faster then NetBSD. No surprise, given the 15 years of software
developement in between. Though, NetBSD is astonishing efficient on
"old" hardware, yet giving contamporarily features like IPv6.)
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
1:58 p.m.
Date: Sun, 7 Oct 2007 21:57:42 +0200> From: jkunz
at unixag-kl.fh-kl.de> To: cctalk at classiccmp.org> Subject: Re: VAX 11/750
rescued, alas...> > On Sat, 06 Oct 2007 17:07:03 -0600> J Blaser <oldcpu2 at
rogerwilco.org> wrote:> > > 2. Is the L0005 or the L0008 preferred? Which one
is easier to use> > with VMS? With NetBSD? (Gee, a random thought just hit
me...is> > there ULTRIX for this beastie?)> There should be ULTRIX for the
11/750.> > An other option is 4.3BSD-Tahoe. You can get it from TUHS or the CSRG>
CDs. Once I instaled it on a MV II, that was upgraded to a MV III+ after> install. It
was really fun to work with that old software. (And it felt> much faster then NetBSD.
No surprise, given the 15 years of software> developement in between. Though, NetBSD is
astonishing efficient on> "old" hardware, yet giving contamporarily features
like IPv6.)> -- > > > tsch??,> Jochen> > Homepage:
http://www.unixag-kl.fh-kl.de/~jkunz/
Just my 2 ct, I have an 11/750, but not yet had a good look at it.
I know it boots VMS from an RA81, but can't remember the version.
This is DEC hardware, so will NEVER run NetBSD or anything non-DEC
on it. If I want to run non-DEC software, I'll grab a stupd PC!
I found this a good page: http://www.vaxarchive.org/hw/750faq.html
Somebody (in The Netherlands) promised to send me a CD-ROM with
Ultrix for the 11/750, and I gave him 10 euro to cover expenses.
Alas, after 2 e-mails, I never heard of him ... so I would be very
interested in an Ultrix CD-ROM for the 11/750 too.
- Henk, PA8PDP
www.pdp-11.nl
8 Oct
8 Oct
4:24 p.m.
Henk Gooijen wrote:
Just my 2 ct, I have an 11/750, but not yet had a good look at it.
I know it boots VMS from an RA81, but can't remember the version.
This is DEC hardware, so will NEVER run NetBSD or anything non-DEC
on it. If I want to run non-DEC software, I'll grab a stupd PC!
As a curiosity, I might want to try BSD or NetBSD at some point, but I
agree with you. I'm hoping to run VMS on this thing as the more or less
permanent software environment. Still, it might be fun to explore what
the state-of-the-art in BSD was like back then on this equipment. Like
I said, as a curiosity.
I found this a good page:
http://www.vaxarchive.org/hw/750faq.html
Yes, that has already proven to be useful as I get myself up to speed on
this 'big' VAX.
Somebody (in The Netherlands) promised to send me a CD-ROM with
Ultrix for the 11/750, and I gave him 10 euro to cover expenses.
Alas, after 2 e-mails, I never heard of him ... so I would be very
interested in an Ultrix CD-ROM for the 11/750 too.
Too bad the CD never arrived. <grumble> It would be interesting to see
Ultrix on this beastie.
I'm presently running Ultrix 4.5 on a MIPS R3000-based DECsystem 5400,
with a fairly complete docset for Ultrix 4.0), and I also have several
flavors of Ultrix 4 for VAX that I've played with on a Vs3100, so have
some familiarity with these newest versions. Still, there's no telling
what BSD4.3 or Ultrix 1.x would be like. Be kinda fun to find out.
As Jochen mentioned, some of the ancient BSD stuff is available from
TUHS or on the CSRG CDs. I sprang for the CSRG CDs last year, but
haven't been smart enough yet to try any of that stuff out. I'm getting
there, but maybe this system will give me reason (and a platform) to try
that old BSD stuff out.
- Jared
11 Oct
11 Oct
11:08 a.m.
On Mon, 08 Oct 2007 17:24:56 -0600
J Blaser <oldcpu2 at rogerwilco.org> wrote:
I also have several flavors of Ultrix 4 for VAX that
I've played with
on a Vs3100
Why not install it on the 11/750? There should be some way to prepare
bootable ULTRIX media with a VAXstation 3100 or MicroVAX running ULTRIX.
Or netboot the 11/750...
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
14 Oct
14 Oct
6:02 p.m.
Jochen Kunz wrote:
On Mon, 08 Oct 2007 17:24:56 -0600
J Blaser <oldcpu2 at rogerwilco.org> wrote:
I'm sure I will, at some point. My interest in these old systems (that
I never had a chance to use until now) are seeing how they behave and
perform with different hardware and software configurations. In fact,
it's the act of getting the thing installed and running that makes for
the fun.
And, netbooting shouldn't be too bad. (Hmm...I hadn't even yet wondered
if the 11/750 is capable of netbooting until you mentioned it.)
As has been mentioned previously in this thread IIRC, a VAX should
really be running VMS, but Ultrix is DEC stuff too, after all. I do
believe, though, that I'll end up _keeping_ VMS running on this thing,
once I've had my fill at experimenting with Ultrix on it.
- Jared
I also have several flavors of Ultrix 4 for VAX
that I've played with
on a Vs3100
Why not install it on the 11/750? There should be some way to prepare
bootable ULTRIX media with a VAXstation 3100 or MicroVAX running ULTRIX.
Or netboot the 11/750...
8 Oct
8 Oct
1:09 a.m.
On 10/7/07, Jochen Kunz <jkunz at unixag-kl.fh-kl.de> wrote:
There is. Finding it might be tricky, though, and I forget what
versions run on the 11/750, but ISTR we started with Ultrix 1.1
sometime around 1988 (and it wasn't particularly new then).
On Sat, 06 Oct 2007 17:07:03 -0600
J Blaser <oldcpu2 at rogerwilco.org> wrote:
> 2. Is the L0005 or the L0008 preferred? Which one is easier to use
> with VMS? With NetBSD?
There are no OS dependencies that I am aware of, beyond how much
physical RAM you have to stuff into the box. We ran 4.0BSD and 4.1BSD
(and VMS 3.4, I think) on an 11/750 w/2MB. When our leased system
went away, I added the extra memory line to the backplane and took
that same 11/750 to 8MB, where it still remains. On that machine, we
ran VMS 4.x and various versions oUltrix.
(Gee, a random
thought just hit me...is there ULTRIX for this beastie?)
There should be ULTRIX
for the 11/750. An other option is 4.3BSD-Tahoe. You can get it from
TUHS or the CSRG
CDs. Once I instaled it on a MV II, that was upgraded to a MV III+ after
install. It was really fun to work with that old software. (And it felt
much faster then NetBSD. No surprise, given the 15 years of software
developement in between. Though, NetBSD is astonishing efficient on
"old" hardware, yet giving contamporarily features like IPv6.)
Unless you are a dedicated DEC masochist, I can recommend exploring
4.3BSD-Tahoe vs Ultrix.
But for me, even though we did run both BSD and VMS back in the day,
if I were going to pay to power a Unibus VAX, I'd set it up to run VMS
and leave BSD to more generic hardware.
-ethan
7 Oct
7 Oct
12:54 a.m.
On 10/6/07, J Blaser <oldcpu2 at rogerwilco.org> wrote:
Ethan Dicks wrote:
> I did notice you have a cable hanging down for a UDA50... it's likely
> that they had both SI disk _and_ Unibus-attachd SMD disks.
Grrr... I _meant_ *SDI* disks, not SMD. RA81s, RA90s, etc.
Oh, yes, thanks for the reminder. Indeed there are
about a half-dozen
carts floating around in the bottom of the cabinet. I haven't even
extracted them yet to see what they are. But I'll definitely want to
get an image of them, if I can, once the drive is revived. I wonder,
can the integrated TU58 be (temporarily) cabled to something like the
PDP-11/23+ that I have, so that I could image those carts first before
trying to use them in the VAX (eventually)? Is it just a standard
serial connection coming off of the drive, like the desktop TU58
subsystems, or is it something lower level?
Electrically, it's a standard serial interface, but I think there
might be an odd cable because it's an 11/750-internal cable. Nothing
insurmountable with a willingness to make a cable adapater.
Yes, you could use an 11/23+, or even a modern machine running DOS or
UNIX and one of the several TU-58-slurping programs out there.
I personally use a dual TU58 from an 11/725 and a PC to read my carts.
I forget, at the moment, which program I'm using, but it's one of the
old, standard ones that's been kicking around for years. I have about
an 80% success rate with the tapes I've read so far.
Oh... you could eventually substitute a PC or FLASH-based TU58
emulator in place of the drive, but in practice, we only ever used our
TU58 for booting diagnostics or Standalone Backup for OS installs, or
loading the DEC Microcode patch... come to think of it... the
Microcode patch (which we started using around VMS 4.6 or 4.7) would
be an excellent use for a TU58 emulator. Software-based ones are out
there, just like the tapedumping packages, but except for an ancient
8051-based Spare Time Gizmos hardware TU58 emulator (now out of
production), I don't know of any hardware TU58 emulators, but every
once in a while, I kick around the idea of building one (with a CF
socket for storage, and an LCD to see what the emulator is doing).
Looks like this is going to be a somewhat lengthy
revival, with lots of
things to consider, detail-wise.
That seems likely.
Actually, I just can't see myself scrapping the
machine. It would be a
real shame to do that, so I'm going to do my best to get the backplane
repopulated, cobble some storage, and light it up!
Good to hear. Keep up the good work.
-ethan
P.S. - as for adding wires to the backplane, any wire-wrap tool should
suffice, including the manual tool that Radio Shack used to sell
(looks like a Jeweler's Screwdriver, with a wire-stripper stored in
the handle). No unusual tools (beyond ordinary WW tools) are
required.
P.P.S - if you are *lucky*, there are plastic alignment blocks on the
backplane where the cables tap into the off-board I/O area. If not,
you might want to track down the installation manual for the SI
9700/9900. More with Massbus or Unibus adapters, I've seen 2x20
plastic blocks that slide down over the pins to help connector
orientation and registration, but they aren't required, as long as you
get the cables on right the first time.
8 Oct
8 Oct
3:40 p.m.
Ethan Dicks wrote:
This is useful to know. I've only had experience using Will Kranz' TU58
emulator on a PC running against my PDP-11/23+, but if it's just a cable
then it'll be pretty easy to get it connected to the RT-11 environment
and capture the images. A simple serial cable is no sweat.
In the last couple of days I've had a chance to poke around inside and
extract the carts. Looks like there are four altogether (I thought
there were six), three of which look to be DEC original carts for bits
of FORTRAN 4.4, and the fourth is some kind of driver/diagnostic tape
for the Systems Industries 9700 board, looks like.
trying to use them in the VAX (eventually)? Is
it just a standard
serial connection coming off of the drive, like the desktop TU58
subsystems, or is it something lower level?
Electrically, it's a standard serial interface, but I think there
might be an odd cable because it's an 11/750-internal cable. Nothing
insurmountable with a willingness to make a cable adapater.
Yes, you could use an 11/23+, or even a modern machine running DOS or
UNIX and one of the several TU-58-slurping programs out there.
I personally use a dual TU58 from an 11/725 and a PC
to read my carts.
I forget, at the moment, which program I'm using, but it's one of the
old, standard ones that's been kicking around for years. I have about
an 80% success rate with the tapes I've read so far.
Mmmm... I doubt the four carts that I have are particularly rare,
someone probably has an image of these already, but I just like to copy
everything that comes my way. Who knows? And based on your success
rate, if I see similar results, I might get lucky and be able to copy
the four carts I have, with an imaginary fifth cart making up the 20%
that are unreadable. ;-)
Oh... you could eventually substitute a PC or
FLASH-based TU58
emulator in place of the drive, but in practice, we only ever used our
TU58 for booting diagnostics or Standalone Backup for OS installs, or
loading the DEC Microcode patch... come to think of it... the
Microcode patch (which we started using around VMS 4.6 or 4.7) would
be an excellent use for a TU58 emulator.
I'm not too worried about this at the moment, at worst I can use a PC
running some type of TU58 emulation, but a simple dedicated device might
come in handy when all of these TU58s start dying off for good, replaced
roller or not.
P.S. - as for adding wires to the backplane, any
wire-wrap tool should
suffice, including the manual tool that Radio Shack used to sell
(looks like a Jeweler's Screwdriver, with a wire-stripper stored in
the handle). No unusual tools (beyond ordinary WW tools) are
required.
Okay, I can probably handle that. I have a simple WW tool exactly as
you describe that I occasionally use on DLV11-Js and whatnot, so as long
as I know what pins to connect, should be doable. ;-)
P.P.S - if you are *lucky*, there are plastic
alignment blocks on the
backplane where the cables tap into the off-board I/O area. If not,
Haven't examined that side of the backplane yet...
you might want to track down the installation manual
for the SI
9700/9900.
So far no luck on bitsaves or manx. I'm still on the hunt, though...
- Jared
6279
days inactive
6288
days old
12 comments
5 participants
participants (5)
-
ethan.dicks＠gmail.com -
healyzh＠aracnet.com -
henk.gooijen＠hotmail.com -
jkunz＠unixag-kl.fh-kl.de -
oldcpu2＠rogerwilco.org