Catching up here, so it might be that this have been sorted out in later
mails...
Josh Dersch <derschjo at mail.msu.edu> wrote:
> Ok, finally stopped being distracted by other shiny objects for long
> enough to do some more fiddling with the 11/40.
>
> And of course, instead of hooking up the logic analyzer, I decided to
> play around with the Console SLU/LTC board. Because I evidently don't
> follow suggestions well.
>
> But this has a good ending, sort of. Maybe.
>
> So the SLU was unresponsive no matter what I did. Tried it at 9600
> baud, no go. Dialed it down to 300, no dice. Checked the continuity of
> the dip switches, of which there are approximately 500. No problems
> there. Checked, and double-checked the wiring on the serial cable I
> built. No go. Stole the cable from my 8/e... still no good.
>
> So I moved it out of the 9th slot on the processor backplane and into
> the first slot on Unibus backplane. (And put a grant card in the 9th
> slot...) And hey, it works. Toggled in a short "echo" program and what
> I type on the terminal keyboard is echoed back, at a blistering 300 baud.
Excellent!
> So... clearly there's something wrong with the SPC slot on the processor
> backplane. A couple more questions:
>
> 1) Is the NPG grant on the unibus slot on the processor backplane (slot
> 9) supposed to be connected to the NPG grants on the Unibus expansion?
> That is -- right now if I set my DMM to continuity mode and put one
> probe on CA1 on the first slot of the unibus expansion, and the other on
> CB1 on the last slot of the unibus expansion, since all NPG grant
> jumpers are in place, the DMM shows the circuit as closed. This is as
> I'd expect. However, if I move the probe from CA1 on the first slot of
> the expansion to CA1 on slot 9 of the processor backplane, the circuit
> is then open. I'm guessing this is not correct. (There is currently an
> NPG jumper installed on slot 9.)
Are you *sure* slot 9 in the processor backplane really is a Unibus
slot??? More correctly stated: the unibus out in the backplane A and B
don't neccesarily imply that C-F is a Unibus SPC slot.
I haven't checked the 11/40 drawings or manuals, and I assume you have
been reading them some. Please check this.
It's a big mistake to just assume that one slot is like another...
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
I was perusing DN's "Sherlock Ohms" series when I came across this
article:
http://www.designnews.com/blog/Sherlock_Ohms/15423-
The_Adventure_of_the_Camera_Shy_Computer.php?nid=4785&rid=1504665
Has anyone tried a camera flash as a way of very quickly erasing
EPROMs?
--Chuck
David writes:
? Anyone here use an Extech multimeter? This thing seems
? to get confused with certain capacitors. In particular,
? a new 10uF electrolytic register randomly from 1 to 8
? nF whereas a 1-year-old 1uF electrolytic registers fine.
I never trust autoranging multimeters. What's happening is that it is applying a charging current, seeing a dV/dt response that's in a different range, trying to switch to a different range, applying a different charging current, seeing dV/dt in some other range, switching to a different charging current, etc.
The textbook definition of capacitance I = C dV/dt works great in a truly linear world but old electrolytics have leakage, soakage, nonlinearities, and other things messing up the textbook definition.
Soakage is always fun. Take a big electrolytic, short it out and remove the short, let it sit for a while on the bench, then put a hi-impedance voltmeter on it. It will not read 0V.
Tim.
"Zane H. Healy" <healyzh at aracnet.com> wrote:
> On Fri, 5 Jun 2009, Sridhar Ayengar wrote:
>
>> > Dave McGuire wrote:
>>>>>> >>>>> It's damnably slow, but at least it works.
>>>>> >>>> Yep. The scary thing is...an OS like RSX-11 or RSTS/E is quite zippy
>>>>> >>>> on a machine like that.
>>>> >>>
>>>> >>> Hmmm. Porting (or writing a work-alike of) RSX-11 for a newer
>>>> >>> architecture (suck as PC -- for the low cost) comes to mind.
>>> >>
>>> >> That would be extremely yummy.
>> >
>> > I wonder how hard it would be? I can't say that I'm very familiar with the
>> > capabilities of RSX, but, considering the size of the code we're talking
>> > about, could it be possible that it wouldn't involve as much work as writing
>> > a more modern, featureful, cluttered, bloaty operating system?
>
> The main problem I see with porting it is that to do so would be in
> violation of copywrite. The second problem I see is that I'm not sure what
> exists in the way of source code. You would need some sort of Macro-11 to
> Macro-x86 compilier. An easier port might be something like RSTS/E, though
> the source code for it is somewhere around 150MB, IIRC.
RSX ships with full, commented source code. So the OS itself isn't a
problem. Applications are where you'd suffer.
But I don't think a MACRO-11 compiler for x86 would be the solution.
We're talking about the OS here. There is way too much hardware-specific
things going on that needs to be done differently on an x86. I'd rewrite
it, using the same layout of the code and everything, but rewritten to
use the x86 architecture instead. The MMU is different, and lots of code
is playing with that. And registers and register conventions differ, not
to mention processor context, and locking mechanisms.
> Realistically time might be better spent on writing a TCP Stack and running
> it under an emulator.
Probably. I already have most of the TCP/IP stack running. :-)
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 Thu, Jun 11, 2009 at 5:24 PM, Sridhar Ayengar<ploopster at gmail.com> wrote:
> Even today, one of my favorite diagnostic tools is the two-digit display on
> the front of RS/6000s.
I haven't had the pleasure, but with so much time spent on various
models of Elf, I approve.
One of my favorite diagnostic hacks is Morse code messages blinked out
via the power LED on an Amiga. If the processor isn't totally wedged
and the hardware isn't so broken as to allow I/O port access, you can
get your message.
Rather low bandwidth, but huge portions of the machine can be borked
and it still works.
-ethan
Was the person injured?
I understand about the hardware thing, I had assumed that the company had aqcuired it on your recommendation. It didn't occur to me that you would loan them your own hardware.
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
--- On Fri, 12/6/09, Daniel Seagraves <dseagrav at lunar-tokyo.net> wrote:
From: Daniel Seagraves <dseagrav at lunar-tokyo.net>
Subject: Re: UNIX V7
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Date: Friday, 12 June, 2009, 5:52 PM
Dropped the machine (no crate, it was a local move from another building) off the back of the truck and destroyed it. The person unloading it slipped and fell, the machine was thrown about eight feet. The case was broken, drives had failure warnings, and rather than take chances we parted the machine out.
It was replaced because I am not interested in providing free hardware to the company on a long term basis.
On Jun 12, 2009, at 11:09 AM, Andrew Burton <aliensrcooluk at yahoo.co.uk> wrote:
>
> Did they drop the crate it was in from a great height? Or was the vehicle it was being transported in involved in a road accident? Or was it something else?
>
> How much power would it require of the MicroVAX (I'm an Amiga/Speccy person, so have no clue about VAXen or PDP's etc.) too be a DNS server and why replace it if it worked?
>
>
> Regards,
> Andrew B
> aliensrcooluk at yahoo.co.uk
>
>
> --- On Fri, 12/6/09, Daniel Seagraves <dseagrav at lunar-tokyo.net> wrote:
>
> From: Daniel Seagraves <dseagrav at lunar-tokyo.net>
> Subject: Re: UNIX V7
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
> Date: Friday, 12 June, 2009, 4:22 PM
>
> Yes, but nobody will care until the law shows up or we get hacked, in which case things will still be my fault. He who bitches loudest gets what he wants, and I am outnumbered. (We run a data warehouse for government/corporate contractors to locate certified minority owned subcontractors for bidding disclosure compliance purposes.)
>
> To make things a bit more on-topic, for the first two weeks of our operations our DNS server was a MicroVAX standing in for a machine that was destroyed in shipping.
>
To cut a long story short, we have put a 240v/50Hz motor from an IBM
56 verifier in the keypunch and that part works great. We transplanted
the motor cradle and motor start relay too. The manual showed how the
DC power supply could be configured for 115v or 208v or 240v, though
all at 60Hz. Well we tried that and the DC produced was about 41volts
instead of 48v, which was more or less what was predicted by
collective list wisdom. The relay logic intermittently seems to work.
The existing capacitor in the ferro-resonant power supply is marked
15MF (incidentally, how come MF does not mean Mega Farad), and rated
at 330VAC. I think this means ideally I need (90/50)^2 * 15 which is
21.6MF. I have ordered two more capacitors to connect in parallel, one
5uF and one 1.5uF, to give 21.5 total, both at 440VAC.
There was one wire hanging off the bottom of the mechanism which we
have reconnected. The mechanical side gradually came back to life,
probably the grease had gone hard at the surface or oil needed
spreading about a bit. It now fairly reliably moves cards from the
input hopper to the output stacker. There were chads stuck all over
the place and at first, the top row did not poke the chads out of the
holes and we joked about hanging chads and George Bush coming back.
Comparing my old keypunch and this one, there is an auger screw in the
old one but not in this, but after looking through the parts list, it
seems IBM deleted that part. Anyway a 9mm twist drill pushed up the
empty auger hole and twisted and wiggled and a backlog of old chads
and strangely black cloth came out and now it punches cleanly, or at
least it does when the relay logic feels like it. It even prints the
codes. To get alpha I had to hold down the alpha key, though I think
it should latch in logic, probably the low DC supply again.
The whole thing looks like it has been re-sprayed in the right colour/
texture of paint and thoroughly cleaned. Maybe a factory refurbished
unit.
Picture of it with cards in the track here, covers off:
http://www.ict1301.co.uk/emulator/029_03_09
I hope to be using it soon to correct any cards which wreck when I try
to read in the library of ICT 1301 software so I can capture it on my
Mac, from where I can load it via RS232 into my 1301 as well as make
it available to others.
Roger Holmes
Did they drop the crate it was in from a great height? Or was the vehicle it was being transported in involved in a road accident? Or was it something else?
How much power would it require of the MicroVAX (I'm an Amiga/Speccy person, so have no clue about VAXen or PDP's etc.) too be a DNS server and why replace it if it worked?
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
--- On Fri, 12/6/09, Daniel Seagraves <dseagrav at lunar-tokyo.net> wrote:
From: Daniel Seagraves <dseagrav at lunar-tokyo.net>
Subject: Re: UNIX V7
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Date: Friday, 12 June, 2009, 4:22 PM
Yes, but nobody will care until the law shows up or we get hacked, in which case things will still be my fault. He who bitches loudest gets what he wants, and I am outnumbered. (We run a data warehouse for government/corporate contractors to locate certified minority owned subcontractors for bidding disclosure compliance purposes.)
To make things a bit more on-topic, for the first two weeks of our operations our DNS server was a MicroVAX standing in for a machine that was destroyed in shipping.
On Fri, Jun 12, 2009 at 12:09 PM, Andrew
Burton<aliensrcooluk at yahoo.co.uk> wrote:
>> To make things a bit more on-topic, for the first two weeks of our operations our
>> DNS server was a MicroVAX standing in for a machine that was destroyed in shipping.
>
> How much power would it require of the MicroVAX (I'm an Amiga/Speccy person, so
> have no clue about VAXen or PDP's etc.) too be a DNS server and why replace it if it worked?
We ran primary and secondary DNS from a pair of Microvaxen at McMurdo
in the 1990s with no load issues. They served up mcmurdo.gov for all
comers, on and off the Ice (McMurdo has a 24/7 connection to the 'net
via a relay station on Black Island). I think they retired those
servers as part of the Y2K effort, not because they weren't going to
work, but because they had a pile of money to modernize everything
(like replacing the aged 64MB 486-based Novell servers that fed
hundreds of 386SX/16s, etc).
It was fun going down the Ice in the mid-1990s as a PC technician and
finding out that there were VAXen at McMurdo and the Pole. I even got
to help out with the occasional issue (like making a 'phone patch' (HF
radio<->land-based PBX) to talk the Computer Technician at Pole
through a SCSI disk replacement.
I can't give you exact numbers, but I don't see a performance issue
with using MicroVAXen as DNS servers in a moderately busy environment.
If you only had a T1 or smaller to the outside world, there's only so
many requests per second that can fit along with the data going to
previous questors.
I don't know if I could make the same endorsement if you had an OC3
and the traffic to fill it - that would end up being a lot of DNS
requests.
As for "why replace it", I'd say power consumption, possibly skillset
(if I were the only one in the company who could keep it running), and
maybe hardware maintenance concerns (especially if it was an
RQDX3+RD-drive system, not a SCSI system).
-ethan
