Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

No, Brad was not the founder of NewTek.  He did do early designs of the Toaster.
- John


Derp! Checked, he built the first Video Toaster but not the company.
https://en.wikipedia.org/wiki/Brad_Carvey

Thanks for the correction!

--
Ethan O'Toole

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[John Foust]

At 05:13 PM 7/19/2016, et...@757.org wrote:
>I'm sure you know the thing about Garth/Dana Carvey? Him mentioning the Unix 
>book in Waynes World was a nod to his brother, his brother founded NewTek the 
>company behind the Amiga video toaster and the current NewTek Tricaster stuff?

No, Brad was not the founder of NewTek.  He did do early designs of the Toaster.

- John

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

The only ones worth using that I'm aware of are Scream Tracker and Impulse
Tracker and neither was around in the 16 bit ISA days pre-386, IIRC. I
doubt Scream Tracker would be able to function on a 286 anyhow. It puts a
486DX2/66 at about 50% CPU load, from my recollection. The Amiga trackers
were more efficient, but you got fewer channels, too. OctaMED was
8-channel and that seemed massive until it wasn't.


IT was VGA but I think Scream Tracker was a 50 line text mode or 
something. I guess it depends if Scream Tracker used protected 
mode. Hmm intarnet says 386s were out during 1990 which was the year the 
more popular Scream Tracker was released. I swear my friend was playing 
coma.s3m on his Northgate 286-16 via PC Speaker



Several made it there over the years. I can't remember which ones, but I
do remember one day I was listening to Nectarine Radio and heard one of my
own Protracker MODs. That was awesome.


Awesome!


Ahhh, those air-car-mounted-on-hydraulics "ride" thingys? Huh. Laser disc
was always a cool thing, too. Remember "Time Traveler" ? That
"holographic" (it wasn't really but it looked damn cool) game were the
characters appeared in front of some kind of curved mirror volumetric
display uhm, thingamabob? It used a Laserdisc too. Of course I loved Space
Ace and Dragons Lair along with every other self-respecting geek, too.
Also, my favorite was called "Thayer's Quest" in which you were a wizard's
apprentice.


Yes. There is an arcade in Chicago called Galloping Ghost which has both 
of the Sega holographic machines, and some of the laserdisc games like 
Space Ace and Dragons Lair. In the arcade world, due to the unreliability 
of the laserdisc players often used in games like Dragons Lair (it uses a 
real HeNe laser tube!) it's okay for people to move them to the MS-DOS 
Daphne replacement system and such. Normally MAME/emulation is frowned 
upon by collectors but the LD games get an okay. The way they work is 
amusing, the game board drives the LED score and just watches for joystick 
directions and sends the chapter skip commands via RS-232 or RS-422 to the 
serial port equipped commercial LD player in the cabinet. Pretty simple 
but legendary.



Most commercial real estate weasels think you are the next "sucker" coming
through the door. They seem to believe that some old crufty warehouse
that's been empty for a decade is actually worth the ridiculous rents they
charge. You'd think it'd be better to have the buildings occupied and
someone giving you a bit or two to cover the property taxes, but they
still don't seem to see their clients as anything more than walking cash
registers. It's definitely a hard slog to find a screaming deal on space.
All the hacker-spaces here in big-D have lots of folks pitching in to make
ends meet. The first one here with an Ethan-style laser arcade will
definitely get my membership dues.


Hah awesome!


Then there is the problem that nobody but old dudes remember how fun/cool
arcades could be, back in a time when they looked a lot more like
nightclubs. I remember them so crowded you had to go out for some fresh
air. Flynn's Arcade may never live again, but it's still a paradigm of
cool in my mind. Then again, I'm probably too old now to adjudicate "cool"
for anyone. If you do open an laser-illuminated LED-walled arcade, let us
all know so we can put you on the cctalk road-trip map. We'll rent a bus
in Seattle, and drive to your place (or visa versa). I nominate Fred to
run the logistics. I'll drive. :-P


I help with an event each year called MAGFest which is currently in the DC 
area. We had 278  arcade cabinets in the arcade room and a decent 
deployment of classic computers in the museum. The attendance is 20,000 
people or so -- it's a large event. Much of it is video game music 
related, and there is a ton of history and classic computer tie ins there. 
All the synth chips all the machines. The event is an insane amount of 
work though, I think it was 14 26' penske trucks some of which made 3 
trips full of arcade cabinets, and the computer museum stuff occupied 
2/3rds of a truck and was all owned by 3 people (just their personal 
stash.) No big metal mostly plastic micros but it's all hands on.


There is a big arcade event in Seattle / Tacoma that has 450+ games, and 
there is CAX in California which just happened that has a large 
collection. They have a lot more people with lower numbers of games from 
what I understand where MAGFest has a handful of collectors with very 
large collections.


There is definitely interest in the retro computer stuff growing outside 
of the age group the reminisces about it. There is also some cross over I 
think between the arcade and classic computer (plastic micro) crowd.



 --
Ethan O'Toole

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Chuck Guzis]

On 07/20/2016 05:59 AM, Paul Koning wrote:

> Three phase power shows up in a bunch of places.  Some high current 
> power supplies (pre switching era) use three phase input to increase 
> the ripple frequency and reduce its amplitude, which significantly 
> reduces the size of the required filter capacitors.  I remember that 
> in the KL-10.  CDC 6000 mainframes go further, not only using 3
> phase but also 400 Hz power for that reason (that also shrinks the 
> transformers).

Indeed, I was going to mention this.  A full-wave 3-phase rectifier
configuration produces ripple at six times the distribution frequency
and the output is largely DC.   Even more interesting is the use of a
transformer with both wye- and delta-configured secondaries.  This
introduces a bonus phase shift of 30 degrees, with the result that the
ripple frequency is twelve times the mains frequency (e.g. 720Hz on 60Hz
mains).

I remember working summers as a projectionist at a drive-in movie
theater that used carbon-arc lamps.  Many such installations simply used
a motor-DC generator for the arc supply, but one theater used a
transformer-rectifier setup on 3-phase power.  Even above the noise of
the projector and the exhaust fans, you could hear the 360 Hz "whine" of
the arc lamps.

3 phase induction motors are simple in the extreme--no starting
capacitors or coils.  I think (but am not sure) that they also deliver a
lot more starting torque than the typical single-phase induction
motor--at least that's been my experience with machine tools.

FWIW,
--Chuck

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Wed, 20 Jul 2016, et...@757.org wrote:
> Very cool! I'm a.d.d. a bit with hobbies. On the synth side I recently 
> picked up a Roland MT-32, so that was an achievement unlocked. Hope to 
> find an Oberheim Matrix 6 at some point.

I'm not a keyboard guru like some on the list, but I've owned a Roland 
FP-9 and Alesis DG8. Now I use a Yamaha Clavinova. I miss the DG8, but I 
traded it off once it's internal amp started fritzing out. 

> I started computeres on Atari 800XL, then next computer was family's 
> Tandy 1000SX.

I had a friend with an Atari 800XL and I was very impressed with it. I 
remember a few demos (one with a metallic rendered robot walking toward 
you, I remember was most impressive). I was surprised that it was just an 
8bit machine. At first I thought it might have been 16 bit! 

> At some point ended up with a Sound Blaster 1.0 in that (Still have the 
> SB.) I don't remember if there was ever a tracker on that, but I 
> remember Scream Tracker on the 386 (same sound card IIRC.)

The only ones worth using that I'm aware of are Scream Tracker and Impulse 
Tracker and neither was around in the 16 bit ISA days pre-386, IIRC. I 
doubt Scream Tracker would be able to function on a 286 anyhow. It puts a 
486DX2/66 at about 50% CPU load, from my recollection. The Amiga trackers 
were more efficient, but you got fewer channels, too. OctaMED was 
8-channel and that seemed massive until it wasn't.

> Spent a lot of time messing with Scream Tracker and Renaissance Composer 
> 669.

Yes! I almost forgot about Composer, that was another good one.

> If you haven't looked, look on the hornet mod archive to see if any are 
> on there?

Several made it there over the years. I can't remember which ones, but I 
do remember one day I was listening to Nectarine Radio and heard one of my 
own Protracker MODs. That was awesome.

> There was recently a video from popular artist deadmau5 where he was 
> driving around interviewing some DJ and he asked the guy if he used to 
> mess with ScreamTracker and all that -- I was pretty shocked.

He was just showing proper street cred. +1 Deadmou5

> Interesting! Never seen the show, we tried to go to it once while at 
> Defcon but messed up on the time. So they're still running it on an 
> Amiga? That's awesome!

It took some extra hard Googling to find anything about it. The only time 
I'd even heard about it was when I was actually in Vegas working as a Def 
Con goon.

> Some of the amusement parks had ride simulators that used Amiga + Laser 
> disk. It's interesting where the Amiga found it's niche.

Ahhh, those air-car-mounted-on-hydraulics "ride" thingys? Huh. Laser disc 
was always a cool thing, too. Remember "Time Traveler" ? That 
"holographic" (it wasn't really but it looked damn cool) game were the 
characters appeared in front of some kind of curved mirror volumetric 
display uhm, thingamabob? It used a Laserdisc too. Of course I loved Space 
Ace and Dragons Lair along with every other self-respecting geek, too. 
Also, my favorite was called "Thayer's Quest" in which you were a wizard's 
apprentice.

> Very cool! I always think about trying to do some sort of music venue 
> with a focus on live music + video recording / live streaming, or 
> arcades + old computers.


> Here in Northern VA everything is crazy expensive tho, so coming across 
> commercial space for pennies is difficult (at this moment.)

Most commercial real estate weasels think you are the next "sucker" coming 
through the door. They seem to believe that some old crufty warehouse 
that's been empty for a decade is actually worth the ridiculous rents they 
charge. You'd think it'd be better to have the buildings occupied and 
someone giving you a bit or two to cover the property taxes, but they 
still don't seem to see their clients as anything more than walking cash 
registers. It's definitely a hard slog to find a screaming deal on space. 
All the hacker-spaces here in big-D have lots of folks pitching in to make 
ends meet. The first one here with an Ethan-style laser arcade will 
definitely get my membership dues.

Then there is the problem that nobody but old dudes remember how fun/cool 
arcades could be, back in a time when they looked a lot more like 
nightclubs. I remember them so crowded you had to go out for some fresh 
air. Flynn's Arcade may never live again, but it's still a paradigm of 
cool in my mind. Then again, I'm probably too old now to adjudicate "cool" 
for anyone. If you do open an laser-illuminated LED-walled arcade, let us 
all know so we can put you on the cctalk road-trip map. We'll rent a bus 
in Seattle, and drive to your place (or visa versa). I nominate Fred to 
run the logistics. I'll drive. :-P

-Swift

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

I knew it! Piano, bass, violin, and guitar, here. I play them all badly
but guitar a little less badly. I've been an amateur for about 10 years
and I've been taking guitar lessons for about three years, now.
Sax, eh? Cool. I've never tried a reed-based instrument.


Very cool! I'm a.d.d. a bit with hobbies. On the synth side I recently 
picked up a Roland MT-32, so that was an achievement unlocked. Hope to 
find an Oberheim Matrix 6 at some point.



You have all the cool sound gear you need if you have an ST and a machine
with a GUS! Well maybe an Amiga with Octamed or Protracker, but Scream
Tracker and Impulse Tracker also rocks fairly hard with a GUS, so never
mind. :-)


I started computeres on Atari 800XL, then next computer was family's Tandy 
1000SX. At some point ended up with a Sound Blaster 1.0 in that (Still 
have the SB.) I don't remember if there was ever a tracker on that, but I 
remember Scream Tracker on the 386 (same sound card IIRC.) Spent a lot of 
time messing with Scream Tracker and Renaissance Composer 669.



As you can tell, I like trackers. I wrote a few MOD/IT/S3M files "back in
the day".


If you haven't looked, look on the hornet mod archive to see if any are on 
there? There was recently a video from popular artist deadmau5 where he 
was driving around interviewing some DJ and he asked the guy if he used to 
mess with ScreamTracker and all that -- I was pretty shocked.



Ah... I finally found some mention of it. Check this out:
"The light and sound spectacular runs on a master show controller and
three sub-systems. The controller runs Stage Manager 3000 software on an
Amiga computer originally installed when the show began in 1995. Murphy
said the master controller sends commands to the video-display controller,
light console and digitally automated audio system. The audio system, a
recently upgraded LCS Matrix 3 system, distributes 550,000W of sound
through 220 remote amplifiers located throughout the outdoor mall."
From:
http://www.signweb.com/content/night-lights


Interesting! Never seen the show, we tried to go to it once while at 
Defcon but messed up on the time. So they're still running it on an Amiga? 
That's awesome!


Some of the amusement parks had ride simulators that used Amiga + Laser 
disk. It's interesting where the Amiga found it's niche.




Whoa, very neat. When I was in college I used to run shows out of an old
machine shop in an industrial part of town. It started as just a practice
place. However, I knew a bunch of artists. They weren't just other college
kids but artists who are pretty well known in the area and responsible for
large public works etc... They all had daughters, you see... Anyhow, they
talked me into letting them setup some art "openings" at this same little
dinky venue I had going. One of them was an electrical engineering student
who would come up from Texas Tech and cover the place with LED matrices
that he had built. It was really impressive tech for the 1990s. He could
do things like color cycling, and display static frames, but not
animation. It always brought in lots of folks (200-800 per show usually)
who were impressed by our tiny art shows with the "Light Room" display.
People gave canned food or $$$ to get in and we raised a bit of food and
money for charity that way, too.


Very cool! I always think about trying to do some sort of music venue with 
a focus on live music + video recording / live streaming, or arcades + old 
computers. Here in Northern VA everything is crazy expensive tho, so 
coming across commercial space for pennies is difficult (at this moment.)



--
Ethan O'Toole

RE: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, Mark Green wrote:
> I don't know a lot about data transmission, my main application is 
> display.

Thanks anyway for the informed reply. Do you happen to know the best place 
to view large format holograms? I'm just looking for your personal 
opinion, since you seem to be in the know about such things. I've been 
fascinated with holograms since I was a kid (ie.. the National Geographic 
comment).

> The mathematics behind data transmission and display are similar, they 
> are based on wave propagation and diffraction and lots of Fourier 
> transforms.

FFT is a wonderful and amazing algorithm. It's akin to Diffie-Hellman in 
it's magicalness, to me. Without it, imagine how poor (or non-existent) 
some technologies would be!

> The laser power is not overly important, it's the resolution of 
> diffraction pattern or hologram that you produce.  It's a very redundant 
> coding scheme, so part of the signal can be lost and you can still 
> recover all the information.

Hmm, I'm guessing holograms have their own redundancy methods. I've seen 
Reed-Solomon matrices for such things, but that's the only one I know 
about. People write their Ph.D thesis on such things, so I'm not even a 
hobbyist, just an admirer of such tech. 

-Swift

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

I wouldn't be doing that.  I cited the cg6 by way of contrast.  How the
points get into the display hardware is still open, but a framebuffer
seems unlikely to be involved.  (I suppose a framebuffer with something
like DVI-D could be used as a way to continuously replay sequences very
fast, but it has its limitations.  I'd rather build a hardware ring
buffer, but I tend towards hardware hackery.)


Ah gotcha. In the laser show world there are gadgets properly called DACs, 
that usually connect to a host computer via USB, ethernet, or in the old 
days parallel port or PCI/ISA bus. They usually have 8 to 24 bits per 
channel, and will have channels for X, Y, then colors (Red, blue, green 
for diode based systems -- or some have a lot more channels as it's 
possible to have different sets of the same color on different 
wavelengths. 445nm blue looks a lot different than the 473nm blue, etc.)


The Etherdream is the open hobbyist ethernet/USB connected device and runs 
around $200. The Pangolin FB3 is Pangolin's USB and the FB4 is ethernet. 
The pangolin units mostly only work with Pangolin stuff when it comes to 
modern DACs but the Etherdream has more hobbyist type stuff using it. 
There is an "industry" pinout for the DB25 called ILDA that specifies the 
color and XY pins, safety interlocks and what not. Some DACs are 
differential signalling for running over longer cables.


The old school Pangolin hardware is called QuadMod boards, so if you find 
a QuadMod card in an Amiga or a QuadMod32 in an ISA PC that's what those 
are. The QuadMod2000 runs on PCI computers, but still approaching classic 
since it was a Windows 2000 product.



 -- 
Ethan O'Toole

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, et...@757.org wrote:
> I live in Virginia but go to a number of events every year. I dabble 
> with music a little, have some synths and midi hardware (and of course 
> an Atari ST setup, and a luggable Pentium 200 with a SB/GUS and Voyetra 
> Sequencer!) Also dabble a little with saxophones but it's been a while!

I knew it! Piano, bass, violin, and guitar, here. I play them all badly 
but guitar a little less badly. I've been an amateur for about 10 years 
and I've been taking guitar lessons for about three years, now. 

Sax, eh? Cool. I've never tried a reed-based instrument.

You have all the cool sound gear you need if you have an ST and a machine 
with a GUS! Well maybe an Amiga with Octamed or Protracker, but Scream 
Tracker and Impulse Tracker also rocks fairly hard with a GUS, so never 
mind. :-)

As you can tell, I like trackers. I wrote a few MOD/IT/S3M files "back in 
the day".

> Hmm interesting! https://en.wikipedia.org/wiki/Scala_%28company%29 No 
> mention of freemont street but their current market is digital signage. 
> That would have been one of the earliest LED video screens ever!

Ah... I finally found some mention of it. Check this out:
 
"The light and sound spectacular runs on a master show controller and 
three sub-systems. The controller runs Stage Manager 3000 software on an 
Amiga computer originally installed when the show began in 1995. Murphy 
said the master controller sends commands to the video-display controller, 
light console and digitally automated audio system. The audio system, a 
recently upgraded LCS Matrix 3 system, distributes 550,000W of sound 
through 220 remote amplifiers located throughout the outdoor mall."

From:
http://www.signweb.com/content/night-lights

> I'm sure you know the thing about Garth/Dana Carvey? Him mentioning the 
> Unix book in Waynes World was a nod to his brother, his brother founded 
> NewTek the company behind the Amiga video toaster and the current NewTek 
> Tricaster stuff?

I did know some of that story, but not all. That's really cool. 

> Also, you can put together your own freemont-street-living-room at not 
> totally insane prices now. I put together this LED video screen [...] 

Whoa, very neat. When I was in college I used to run shows out of an old 
machine shop in an industrial part of town. It started as just a practice 
place. However, I knew a bunch of artists. They weren't just other college 
kids but artists who are pretty well known in the area and responsible for 
large public works etc... They all had daughters, you see... Anyhow, they 
talked me into letting them setup some art "openings" at this same little 
dinky venue I had going. One of them was an electrical engineering student 
who would come up from Texas Tech and cover the place with LED matrices 
that he had built. It was really impressive tech for the 1990s. He could 
do things like color cycling, and display static frames, but not 
animation. It always brought in lots of folks (200-800 per show usually) 
who were impressed by our tiny art shows with the "Light Room" display. 
People gave canned food or $$$ to get in and we raised a bit of food and 
money for charity that way, too.

-Swift

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Paul Koning]

> On Jul 20, 2016, at 9:12 AM, Mouse  wrote:
> 
>> As far as sending video from a computer frame buffer, I think it
>> might be way too fast.
> 
> I wouldn't be doing that.  I cited the cg6 by way of contrast.  How the
> points get into the display hardware is still open, but a framebuffer
> seems unlikely to be involved.  (I suppose a framebuffer with something
> like DVI-D could be used as a way to continuously replay sequences very
> fast, but it has its limitations.  I'd rather build a hardware ring
> buffer, but I tend towards hardware hackery.)

Given modern processor speeds, an obvious answer is to do it the same way the 
CDC mainframes drive the console: a program loop feeding coordinates to the 
interface.  You just need a loop that takes less than the acceptable refresh 
interval (30-50 ms or so) which isn't hard to do.  Especially since the 
deflection performance is likely to be the limiting factor.

paul

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Mouse]

> As far as sending video from a computer frame buffer, I think it
> might be way too fast.

I wouldn't be doing that.  I cited the cg6 by way of contrast.  How the
points get into the display hardware is still open, but a framebuffer
seems unlikely to be involved.  (I suppose a framebuffer with something
like DVI-D could be used as a way to continuously replay sequences very
fast, but it has its limitations.  I'd rather build a hardware ring
buffer, but I tend towards hardware hackery.)

/~\ The ASCII Mouse
\ / Ribbon Campaign
 X  Against HTMLmo...@rodents-montreal.org
/ \ Email!   7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Paul Koning]

> On Jul 19, 2016, at 4:58 PM, Wayne Sudol  wrote:
> 
> Laser technology to draw things like this is used in photo typesetters. A
> laser beam is focused onto a thin (about 1/2" thick)  many sided (about 8
> sides i think) spinning mirror. Each facet of the mirror is cut differently
> to deflict the beam up, down or center it on a sheet of moving paper or a
> plate of sensitized aluminum. 

Depending on the typesetter, the spinning mirror might just be horizontal 
deflection, with vertical positioning provided by the film transport motor.  
But in any case, those are raster scan systems.  It's very easy to scan a light 
beam in a regular pattern at high speed, with schemes like this.

DLP (micro-mirror chips) are also raster systems.  

paul

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Wayne Sudol]

Laser technology to draw things like this is used in photo typesetters. A
laser beam is focused onto a thin (about 1/2" thick)  many sided (about 8
sides i think) spinning mirror. Each facet of the mirror is cut differently
to deflict the beam up, down or center it on a sheet of moving paper or a
plate of sensitized aluminum. The more facets you have, the more 'cuts' you
can have and the beam can be deflicted more each time it hits the mirror.
The electronics is mainly used to control the timing/pulsing/power of the
laser beam hitting the mirror.  Using the same idea, a larger mirror could
be used to deflict the beam more and shine it on any surface.

 Think of the scene  in the Val Kilmer movie "Real Genius" where they
advertise a part using a laser beam.





Wayne Sudol
Riverside Press-Enterprise
A Digital First Media Newspaper
1-951-368-9945

On Tue, Jul 19, 2016 at 1:45 PM, jim stephens  wrote:

>
>
> On 7/19/2016 1:22 PM, Noel Chiappa wrote:
>
>> Those have been around for decades - I recall seeing them used to draw
>> things
>> on the sides of building,_many_  moons ago.
>>
> I know that the pen motors from Brush recorders were used eons ago. They
> have frequency response that is very high, and if you had the power to
> drive them would move very quickly.
>
> Also Oscilligraph motors could be used, and already had mirrors mounted on
> the end.
>
> Piezo actuators could be mounted on the Brush motors and swung for a
> second degree of motion as well.
>
> These were in use in the 70's if not earlier.
> Thanks
> Jim
>
> Gould Brush example:
> GOULD-BRUSH-220-Strip-Chart-Recorder-Model-15-6327-57-POWERS-ON-SEE-DETAILS
> http://www.ebay.com/itm/262507072142
>
> Oscillograph:
> HONEYWELL-1406-VISICORDER-OSCILLOGRAPH
> http://www.ebay.com/itm/272248210671
>
>

RE: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Mark Green]

I don't know a lot about data transmission, my main application is display.
The mathematics behind data transmission and display are similar, they are
based on wave propagation and diffraction and lots of Fourier transforms.
The laser power is not overly important, it's the resolution of diffraction
pattern or hologram that you produce.  It's a very redundant coding scheme,
so part of the signal can be lost and you can still recover all the
information.

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Swift
Griggs
Sent: July 19, 2016 6:04 PM
To: General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org>
Subject: RE: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was
Re: Straight 8 up on Ebay just now))

On Tue, 19 Jul 2016, Mark Green wrote:
> In my day job I work on computational holography and other forms of 
> esoteric 3D displays, so I can give you some insight in how these 
> things work.

Holography is amazing. Do you know much about so-called "free space optical"
data transmission? I worked with some gear a few years ago that could
transmit & receive using multiple lasers at 1Gbit. I was fascinated with
that stuff, but the vendor had their folks do all the alignment and
installation. So, I didn't get to work with it much.

I wonder if you've seen faster speeds than that. I also wonder what the
power levels look like for those lasers and what distances the really
serious ones can reach. Can they still work in bad weather? It seemed like
the ones that I mentioned, still worked in the rain.

-Swift

PS: It was the May 1984 National Geographic cover that blew me away and made
me forever respect holography. :-)


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Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Noel Chiappa]

> From: Mouse

> my impression is that they're only for pre-prepared displays, and only
> some displays (notably those that don't involve the beam turning any
> sharp corners

My vague recollection is that they could do pretty sharp corners, but it's
been decades. IIRC, they were multi-coloured.

> Turning sharp corners is the hard part with mechanical deflectors like
> mirrors, as it means very high acceleration of the mechanical parts. 

Probably the trick is to do what old voice-coil actuator drives did for
multi-track seeks, which was to evenly accelerate up to maximum velocity,
coast at that until you got close to the target track, and then evenly ramp
down, so that the head assembly's radial velocity goes to 0 as you get to the
target track. (If you're not moving enough tracks to do the whole thing, you
only ramp up part-way, then ramp back down.) The RK05 drive did this with
fancy analog circuits, but these days one would do it in software.

I would assume one would do something similar with the mirror; evenly
accelerate up to maximum slew rate, then back down at the end of the move, so
that when one gets to the corner, the mirror is mostly stationary, and so not
so much force is needed to sharply change directions. Of course, this might
make the parts of the line where the mirror is moving slower brighter, but
perhaps one could tweak the brightness to compensate.

Noel

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Pete Turnbull]

On 19/07/2016 21:46, Mouse wrote:

You'd probably know, then - what's the fastest way to deflect a
laser beam?  In particular, I'm wondering how practical it might be
to take a laser and turn it into a vector display



Turning sharp corners is the hard part with mechanical
deflectors like mirrors, as it means very high acceleration of the
mechanical parts.  I haven't done the math to be sure, but,
until/unless taught otherwise by testing, I'd feel dubious about
clipping the X and Y signal bandwidths at anything lower than ~1MHz.


If you want to experiment, you might try to find the mirror/coil 
assemblies from a Pioneer laserdisk player or similar.  They consist of 
a small mirror mounted on a moving coil so as to turn on one axis 
through an angle of some +/-10deg (total 20deg).  They're light enough 
to respond somewhere in the kHz (maybe 10s of kHz) range if you only 
need small deflections, rather than the full 20deg.  I've got one here, 
but never got round to trying it out.


--
Pete

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

Killer. I wish we were neighbors, Ethan. We'd be able to throw the most
awesome block parties, I swear. I bet you are a musician, too.


I live in Virginia but go to a number of events every year. I dabble with 
music a little, have some synths and midi hardware (and of course an Atari 
ST setup, and a luggable Pentium 200 with a SB/GUS and Voyetra Sequencer!) 
Also dabble a little with saxophones but it's been a while!



Okay, after talking about the recent roots of that hobby, and in an effort
to keep this slightly on topic, do you know anything about the original
animations used on Freemont street in Las Vegas? I was told that at one
time it was run from an Amiga using Scala "and some other stuff". If you
haven't seen it, it's a giant (uhm, like 4 city blocks) color LED array
and a big sound system.


Hmm interesting! https://en.wikipedia.org/wiki/Scala_%28company%29  No 
mention of freemont street but their current market is digital signage. 
That would have been one of the earliest LED video screens ever!


I'm sure you know the thing about Garth/Dana Carvey? Him mentioning the 
Unix book in Waynes World was a nod to his brother, his brother founded 
NewTek the company behind the Amiga video toaster and the current NewTek 
Tricaster stuff?


Also, you can put together your own freemont-street-living-room at not 
totally insane prices now. I put together this LED video screen, it's a 
square meter of panels, the software screen scrapes Windows desktop sends 
it over gigabit:

https://www.youtube.com/watch?v=78RUIGVvQ5E


--
Ethan O'Toole

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[ethan]

Yeah, me too, but my impression is that they're only for pre-prepared
displays, and only some displays (notably those that don't involve the
beam turning any sharp corners, such as Lissajous figures).
My impression may, of course, have been - be - incorrect, which is what
I'm asking for; if you've seen such displays involving sharp-corner
turns of the beam and run-time chosen displays, then obviously my
impression is incorrect and the technology exists.


The devices are called Galvometers and they work like audio meters. There 
is in deed a mirror, and they are used in an XY pair. Old gas lasers used 
a RF driven crystal to select a specific wavelength of light (and deflect 
all other wavelengths.) Those crystal setups are known as Poly-chromatic 
acouso-optic modulation or PCAOM for short.


The current fastest scanners that I know of on the market for laser show 
display would be the Pangolin Saturns. Next up would be something in the 
6800 series from Cambridge Technology.


The galvos can do sharp turns, text, and graphics. There is software for 
Linux that can do edge tracing and send it out of a modified sound card 
DAC (has to pass DC voltage?) to the X/Y scanner drivers. Most galvos have 
a feedback loop for inertial correction.


The laser display world uses a test frame known as the ILDA (International 
Laser Display Association) and there is a performance benchmark in points 
per second, so 12,000 points per second is old spec, 30,000 points per 
second is a newer spec. Now people are claiming 60 and 90K on the modern, 
expensive, quality scanners. The Chinese stuff is mostly 30K and 40K. The 
old days 8 degrees was the scan width but now people push it way further.


Old technology stored the laser show information on various formats for 
shows ... like 8 track multitrack reel to reel, and then the Alesis SVHS 
based ADAT machines were popular for a while. Now everything is directly 
driven from computer.


Some of the old systems are being recovered here and there, and similar to 
vintage computers people pet them and clean them and take care of them. 
I'm pretty certain some old school stuff existed in the S100 world, but 
none of that has surfaced. There is also analog consoles and the like.


As far as sending video from a computer frame buffer, I think it might be 
way too fast. Also, the more you scan and the faster you scan the laser 
power has to be higher. And there can also be issues with modulating the 
actual laser diodes. Direct solid state run at one rate and diode pumped 
solid state run at another rate.


This is a random picking of a laser graphics show, projected on a scrim. 
It's from LD-2000 which would of been Windows 2000 to XP era software, but 
the show is pushed into a card that is a Motorola 68040 on a board with 
RAM where the card just runs the show once it's loaded. Pangolin's roots 
are on the Amiga so I've always grinned thinking they just put an Amiga on 
a board:


https://www.youtube.com/watch?v=khVGAOLTaTA

There are a few ports of MAME for running vector arcade games into laser 
projectors, the older hardware had quite a bit of flicker.


There is also someone who has rebuilt, from scratch, several older analog 
consoles that had some fame.


China really opened the floodgates with the availability of parts, and 
lots of projectors and low cost galvos. Before China a set of galvos could 
run a thousand or more dollars with the amps. And the PCAOM hardware would 
costs thousands. When I had the argon system I had picked it up from a 
NASA auction while hunting lasers, SGIs, and Suns.


Everyone will probably cry when I say that one of the first NASA auctions 
I went to there was a Convex system there.

RE: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, Mark Green wrote:
> In my day job I work on computational holography and other forms of 
> esoteric 3D displays, so I can give you some insight in how these things 
> work.

Holography is amazing. Do you know much about so-called "free space 
optical" data transmission? I worked with some gear a few years ago that 
could transmit & receive using multiple lasers at 1Gbit. I was fascinated 
with that stuff, but the vendor had their folks do all the alignment and 
installation. So, I didn't get to work with it much.

I wonder if you've seen faster speeds than that. I also wonder what the 
power levels look like for those lasers and what distances the really 
serious ones can reach. Can they still work in bad weather? It seemed like 
the ones that I mentioned, still worked in the rain.

-Swift

PS: It was the May 1984 National Geographic cover that blew me away and 
made me forever respect holography. :-)

RE: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Mark Green]

In my day job I work on computational holography and other forms of esoteric
3D displays, so I can give you some insight in how these things work.

Remember these are vector displays and not raster displays, so the
computational side is not an issue.  You are basically looking at a pair of
D/A convertors that are driven by a pair of parallel ports.  The circuit is
probably a bit more complicated than that, but you get the idea.  This can
be done interactively with no problem.  With a modern CPU you are probably
looking at less than 1% of the CPU time.

The complication occurs with the lasers and the optics.  For an outdoor
display you need a very high power laser, which will literally melt standard
optics devices.  There are special lens and mirrors that are used with high
power lasers, look at Edmund Optics.  The deflection range is relatively
small, around 1 degree.  The limiting factor is how fast you can move the
mirror, which depends on mass and inertia.  With these small deflections you
can get pretty high rates.

Indoors with low light you can get away with much lower power, 10mW is more
than enough.  With this power level you can use standard optics, and the
lasers are quite cheap < $30 as long as you like red.  I've heard of people
using TI DMDs to deflect laser beams.  Even the low end DMDs can display 1
bit raster images at 4000Hz.

One of the problems with this technology is it's hard to modulate the laser
intensity, which greatly restricts the range of colours you can produce.

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Mouse
Sent: July 19, 2016 4:47 PM
To: cctalk@classiccmp.org
Subject: Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was
Re: Straight 8 up on Ebay just now))

>> You'd probably know, then - what's the fastest way to deflect a laser 
>> beam?  In particular, I'm wondering how practical it might be to take 
>> a laser and turn it into a vector display on a handy blank wall [...]
> What bandwidth (deflection rate) do you need?  Full scale in a 
> microsecond?  In 10 microseconds?

Well, if it takes longer than 100ms to replot the display, it will flicker
visibly, and the more under 100ms the better.  In that time I'd like to draw
at least a couple hundred lines, though most of them will be short (line
length maybe 1-15% of corner-to-corner distance).  What kind of
radians/second deflection rates this means depends on how far from the wall
you put the projector.

But, in terms of the bandwidth on the X and Y axis signals?  If we say
200 lines at 25 ms replot (I get 20ms frame rate out of the cg6 for displays
significantly more complex than that - ie, with the cg6 the actual
limitation is the video signal vertical frequency), that's 125us/line.
Turning sharp corners is the hard part with mechanical deflectors like
mirrors, as it means very high acceleration of the mechanical parts.  I
haven't done the math to be sure, but, until/unless taught otherwise by
testing, I'd feel dubious about clipping the X and Y signal bandwidths at
anything lower than ~1MHz.

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Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Greg Stark]

On Tue, Jul 19, 2016 at 5:47 PM, Mouse  wrote:
> For example, I once had a neighbour who replaced an outlet in his
> kitchen.  Turned off the breaker, removed the old one, put in the new
> one, all very nice.  Turned the breaker for that circuit back on and
> popped the service main breaker.

Heh, I knew what was coming here and that it must mean you were in
Canada (and only then checked the sender...)

But all this seems like a red herring. Surely the three-phase power
requiring devices only require three phase for the cooling systems?
Wouldn't it be easier to just use a modern switching power supply to
provide 5V and feed cold air directly from your home hvac and not try
to run 50-year old cooling and power?

-- 
greg

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[jim stephens]

On 7/19/2016 1:22 PM, Noel Chiappa wrote:

Those have been around for decades - I recall seeing them used to draw things
on the sides of building,_many_  moons ago.
I know that the pen motors from Brush recorders were used eons ago. They 
have frequency response that is very high, and if you had the power to 
drive them would move very quickly.


Also Oscilligraph motors could be used, and already had mirrors mounted 
on the end.


Piezo actuators could be mounted on the Brush motors and swung for a 
second degree of motion as well.


These were in use in the 70's if not earlier.
Thanks
Jim

Gould Brush example:
GOULD-BRUSH-220-Strip-Chart-Recorder-Model-15-6327-57-POWERS-ON-SEE-DETAILS
http://www.ebay.com/itm/262507072142

Oscillograph:
HONEYWELL-1406-VISICORDER-OSCILLOGRAPH
http://www.ebay.com/itm/272248210671

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Mouse]

>> I'm wondering how practical it might be to take a laser and turn it
>> into a vector display on a handy blank wall
> Those have been around for decades - I recall seeing them used to
> draw things on the sides of building, _many_ moons ago.

Yeah, me too, but my impression is that they're only for pre-prepared
displays, and only some displays (notably those that don't involve the
beam turning any sharp corners, such as Lissajous figures).

My impression may, of course, have been - be - incorrect, which is what
I'm asking for; if you've seen such displays involving sharp-corner
turns of the beam and run-time chosen displays, then obviously my
impression is incorrect and the technology exists.

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Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Noel Chiappa]

> From: Mouse

> I'm wondering how practical it might be to take a laser and turn it
> into a vector display on a handy blank wall

Those have been around for decades - I recall seeing them used to draw things
on the sides of building, _many_ moons ago. I'm assuming they bounce the beam
off a mirror, and actuate the mirror, but I don't actually know how they
worked.

Noel

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Paul Koning]

> On Jul 19, 2016, at 4:02 PM, Mouse  wrote:
> 
>>> Light show hobby.
> 
> You'd probably know, then - what's the fastest way to deflect a laser
> beam?  In particular, I'm wondering how practical it might be to take a
> laser and turn it into a vector display on a handy blank wall - but
> that requires some very fast acceleration of the spot, probably faster
> than mechanical deflection can support (though if I'm wrong I'd love to
> know it).  For example, does piezoelectricity make a crystal distort
> enough to use it as an optical deflection element in such a scheme?
> (My guess is no, but I don't actually know.)
> 
> I have SPARCstations with cg6s that I can use as vector displays, but
> they are vectors converted to raster.  I'd like to do real vector - a
> parallel port driving a couple of moderately fast D->A converters might
> be able to do it; it might take something better, dunno.  But without
> the deflection mechanism there's no point in even trying to design the
> rest of it.

What bandwidth (deflection rate) do you need?  Full scale in a microsecond?  In 
10 microseconds?

Piezoelectric loudspeakers work up into ultrasonic range.  A mirror attached to 
such an actuator would give you variable deflection.  So 10 microseconds might 
be doable.

A faster (no moving parts) scheme might be to use Kerr cells.  I don't know if 
that has been done, but from what I understand about the Kerr effect it seems 
plausible that it could be.

paul

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, Mouse wrote:
> You'd probably know, then - what's the fastest way to deflect a laser 
> beam?

Whoa. Interesting problem since a photon carries no charge and thus you 
can't horizontally or vertically deflect it with a magnetic field. I guess 
that's why folks make things like these:

http://www.newson.be/rhothor.htm

> In particular, I'm wondering how practical it might be to take a laser 
> and turn it into a vector display on a handy blank wall - but that 
> requires some very fast acceleration of the spot, probably faster than 
> mechanical deflection can support (though if I'm wrong I'd love to know 
> it).

I wonder how laser projectors work. The must use some kind of internal 
screen like the ones that use "lamps". I'm guessing they just use lasers 
instead of lamps to get a brightness and longevity boost.

> For example, does piezoelectricity make a crystal distort enough to use 
> it as an optical deflection element in such a scheme? (My guess is no, 
> but I don't actually know.)

I found mention of something like that in this paper:
http://www.sciencedirect.com/science/article/pii/S1875389214002351

It's in the references:
F. Filhol, E. Defay, C. Divoux, C. Zinck, M.-T. Delaye
Resonant micro-mirror excited by a thin-film piezoelectric actuator for 
fast optical beam scanning

That sounds wicked-cool, by the way. If you ever do build something like 
that, please share some video!

-Swift

Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Karl-Wilhelm Wacker]

They generaly use mirrors -

I would cobble something together by taking the laser diode read head from 
a CD rom,
and removing the diode assembly, and glue a small, thin, front surface 
mirror in its place,

and drive the coil from the output of an audio amp, just to try it out.
A pair of these, at right angles, would give you X/Y deflection.

Karl



- Original Message - 
From: "Mouse" <mo...@rodents-montreal.org>

To: <cctalk@classiccmp.org>
Sent: Tuesday, July 19, 2016 4:02 PM
Subject: Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was 
Re: Straight 8 up on Ebay just now))




Light show hobby.


You'd probably know, then - what's the fastest way to deflect a laser
beam?  In particular, I'm wondering how practical it might be to take a
laser and turn it into a vector display on a handy blank wall - but
that requires some very fast acceleration of the spot, probably faster
than mechanical deflection can support (though if I'm wrong I'd love to
know it).  For example, does piezoelectricity make a crystal distort
enough to use it as an optical deflection element in such a scheme?
(My guess is no, but I don't actually know.)

I have SPARCstations with cg6s that I can use as vector displays, but
they are vectors converted to raster.  I'd like to do real vector - a
parallel port driving a couple of moderately fast D->A converters might
be able to do it; it might take something better, dunno.  But without
the deflection mechanism there's no point in even trying to design the
rest of it.

/~\ The ASCII   Mouse
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Re: LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Mouse]

>> Light show hobby.

You'd probably know, then - what's the fastest way to deflect a laser
beam?  In particular, I'm wondering how practical it might be to take a
laser and turn it into a vector display on a handy blank wall - but
that requires some very fast acceleration of the spot, probably faster
than mechanical deflection can support (though if I'm wrong I'd love to
know it).  For example, does piezoelectricity make a crystal distort
enough to use it as an optical deflection element in such a scheme?
(My guess is no, but I don't actually know.)

I have SPARCstations with cg6s that I can use as vector displays, but
they are vectors converted to raster.  I'd like to do real vector - a
parallel port driving a couple of moderately fast D->A converters might
be able to do it; it might take something better, dunno.  But without
the deflection mechanism there's no point in even trying to design the
rest of it.

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LASERS! && Freemont Street LED array (was Re: Cray J932SE (was Re: Straight 8 up on Ebay just now))

[Swift Griggs]

On Tue, 19 Jul 2016, et...@757.org wrote:
> Light show hobby. Inspired by the Def Leppard music video "Pour some 
> sugar on me."

Killer. I wish we were neighbors, Ethan. We'd be able to throw the most 
awesome block parties, I swear. I bet you are a musician, too.

> Everything is from China and solid state now. There is a laser 
> "con/fest" of sorts and a small bit of vintage computing cross-over. 

Huh, cool! That sounds (and from the videos also looks) fun.

> Like any technology I suppose it grew up along side of personal 
> computing.

> SELEM event in NC: https://www.youtube.com/watch?v=-S75y8-StKE

Neat. What fun!

Okay, after talking about the recent roots of that hobby, and in an effort 
to keep this slightly on topic, do you know anything about the original 
animations used on Freemont street in Las Vegas? I was told that at one 
time it was run from an Amiga using Scala "and some other stuff". If you 
haven't seen it, it's a giant (uhm, like 4 city blocks) color LED array 
and a big sound system.

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, Paul Koning wrote:
> I wouldn't run my $100 little VFC in production, but I expect that the 
> more expensive ones from serious companies like Yaskawa or Allen-Bradley 
> will do just fine.

I forgot about those. I think you are right. I've seen what I believe to 
be massive VCFs in a metal-powder mill with multiple inputs. Those 
probably can provide you with even more redundancy since you can run 
multiple input lines.

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[ethan]

I haven't been able to articulate anything witty, but I'll go ahead and
just say: Ethan I don't know what you do with those BF-lasers, but it
sounds damn awesome, anyway. Your stock just went up. It's hard to make
lasers anything but sci-fi radical coolness.


Light show hobby. Inspired by the Def Leppard music video "Pour some sugar 
on me."


Everything is from China and solid state now. There is a laser "con/fest" 
of sorts and a small bit of vintage computing cross-over. Like any 
technology I suppose it grew up along side of personal computing. Early 
animation/graphics systems probably existed (low quantity) on S100 systems 
then moved to things like the Commodore Amiga (Pangolin) and then IBM PC 
(but using coprocessor cards and stuff.)


SELEM event in NC:
https://www.youtube.com/watch?v=-S75y8-StKE

There are more videos on youtube but I just grabbed one I know.
Just another geekfest, and that's just one of a number of rooms.

--
Ethan O'Toole

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Dale H. Cook]

At 02:41 PM 7/19/2016, Fred Cisin wrote:

> and resulted in high voltage to the 110 outlets, damaging a bunch of minor 
> stuff, such as grinder, space heater, clock, etc.

Obviously a delta with a high (aka "wild") leg.

Dale H. Cook, Roanoke/Lynchburg, VA
Osborne 1 / Kaypro 4-84 / Kaypro 1 / Amstrad PPC-640
http://plymouthcolony.net/starcity/radios/index.html 

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Fred Cisin]

On Tue, 19 Jul 2016, Paul Koning wrote:
Anything powered by electric motor above 2 hp or so often comes in 3 
phase, and when you get to somewhat higher power (5 hp or so) it seems 
to be about the only option.  Lathes and milling machines are good 
examples.


and air compressors in automotive shops, maintaining a large tank of 
compressed air.



3-phase comes in "delta" or "Wye"("Y")
some installers don't know the difference!
I experienced TWO misdone installations.  One was an auto garage, and 
resulted in high voltage to the 110 outlets, damaging a bunch of minor 
stuff, such as grinder, space heater, clock, etc.


The other was was a PDP installation.  After excessive downtime of third 
party disk drive, the community college had sold it to a neighboring 
school district, and bought a roomful of PCs. Microsoft PC COBOL and 
Fortran were crap, but quite adequate for teaching the languages, and it 
was great to have dozens of machines for students to use without fear of 
downtime.  PG (our power company) agreed to buy a new replacement 
computer, if those involved would go along with the fiction that it had 
been a lightning strike (NOT common here).  The bad drive ceased 
to be a problem.  Everybody was happy, and PG got to call it a donation 
on their taxes.

Wiring Regulations. RE: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Dave G4UGM]

In the UK we have, for DOMESTIC premises something call "Part P"

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Mouse
> Sent: 19 July 2016 17:47
> To: cctalk@classiccmp.org
> Subject: Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)
> 
> >> [...electrical wiring...]
> > This very definitely is an area where, if you're not 100% comfortable
> > with t$
> 
> Also, know your own limits.  A depressing number of people think they're
> more competent than they are.
> 
> For example, I once had a neighbour who replaced an outlet in his kitchen.
> Turned off the breaker, removed the old one, put in the new one, all very
> nice.  Turned the breaker for that circuit back on and popped the service
> main breaker.
> 

In the UK we used to have an inspection regime. You did the work, they would
inspect.

These days, for DOMESTIC premises we have something call "Part P" which
limits what a householder can and cannot do.

So you can generally do "like for like" replacements, add additional outlets
where permitted and one or two other things.

Originally all work in Kitchens was defined as "Special" and was notifiable,
but this was modified so that is no longer the case.

So as the above is a "like for like" replacement, I believe it is currently
permitted in the UK.

Of course in a Museum, or even a Scout Hut, provided it does not share a
supply with residential premises then any one can do the
Work so long as it is later inspected.

... the problem with Part P is that it encourages a "tick box" approach and
the Electrician who replaced my "Consumer Unit" (distribution panel)
With a new one with multiple RCD's which tripped suggested it would be
simpler to re-wire rather than fix the existing wiring. 
This sort of approach seems common. The actual fault was that I have a pair
of linked smoke detectors, and one was connected via one RCD, the other via
a different RCD.
The connection between the two was sufficient to cause an imbalance. I
replaced them with wireless linked smoke detectors and all works well


> When I investigated, it turned out the new outlet still had the bridging
piece
> that shorts together the hots for the two outlets, and this was a kitchen
> outlet and thus had separate circuits for each half (and, as is often the
case,
> they were on adjacent fingers in the breaker box and thus on different
> phases).  So, of course, the new outlet shorted the two hot phases
together.
> 
> He didn't have the experience to recognize that those shorting pieces
exist,
> to realize that having four conductors instead of three coming to the
outlet -
> or its being a kitchen outlet - likely means the two halves are on
different
> circuits and thus likely different phases, or the electrical understanding
to put
> those facts together.  Which wouldn't've been a problem, except that he
> thought he was fine - he didn't bring me in until the main service breaker
> blew.  (He did, fortunately, have enough sense for that to tickle his
> "something I don't understand happened, call for help" reaction.)
> 
> I've been doing electrical work since I was maybe ten or twelve, when I
> helped my parents wire the house they were building.  (My father inspected
> my work first; then, this being de rigeur there-and-then, it was inspected
by
> a suitable authority.  Only then was it energized.)  I don't hesitate to
do
> routine house electrical work, maybe even installing 30A outlets (though
I'd
> make sure I looked up the appropriate gauge of wire, and probably then
> used the next larger gauge).  But I'd call in someone more experienced for
> something well outside my own experience, like (say) dealing with 600/600
> service.
> 
> I would say that, if you don't have a good deal of experience, find
someone
> who does to look over your work before you energize it.
> Indeed, some jurisdictions require that for work done by unlicensed
persons
> - or at least used to, and I would assume some still do.  Even if yours
doesn't,
> it strikes me as the smart thing to do.
> 
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Dave
G4UGM

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Paul Koning]

> On Jul 19, 2016, at 1:51 PM, et...@757.org wrote:
> 
> ...
> I've heard sometimes the utility will indeed give you 3phase but you have to 
> pay them to replace the transformer and it's very very expensive. Normally 
> it's people buying used milling equipment that are after it from my 
> experience. There are rotary converters and solid state converters but 
> probably not ideal for huge loads.

Anything powered by electric motor above 2 hp or so often comes in 3 phase, and 
when you get to somewhat higher power (5 hp or so) it seems to be about the 
only option.  Lathes and milling machines are good examples.

The expense of a new service for 3 phase is one issue; it may not be available 
at all.  A lot of US rural areas have a single wire running along the street.  
The only way you could get 3 phase service is for the utility to replace that 
by 3 wires, for however many miles it takes to get to the spot where their 3 
phase service ends.

Rotary converters have a good reputation among home workshop types.  You can 
build them or buy them.  I liked the VFC approach when I realized how 
inexpensive a basic one can be, plus I get variable speed and instant reverse 
and controlled braking as well.

paul

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, et...@757.org wrote:
> The Cray is single phase, the only thing I've ever owned that was 3 
> phase was the laser stuff. Now my solid state laser projector uses 100 
> watts and producsed half the power of the argon that used to take 3ph @ 
> 30A (and still tripped the breaker sometimes.)

I haven't been able to articulate anything witty, but I'll go ahead and 
just say: Ethan I don't know what you do with those BF-lasers, but it 
sounds damn awesome, anyway. Your stock just went up. It's hard to make 
lasers anything but sci-fi radical coolness.

> I've heard sometimes the utility will indeed give you 3phase but you 
> have to pay them to replace the transformer and it's very very 
> expensive.

Yep. It's happened in every case I've been involved with here in Colorado 
(ie.. residential or small buildings, not in data centers).

> Normally it's people buying used milling equipment that are after it 
> from my experience. There are rotary converters and solid state 
> converters but probably not ideal for huge loads.

... and as I mentioned before, they can break. So, even if your VCF will 
handle the load, your uptime requirement might be a dealbreaker if you 
have commercial intentions.
 
> The Cray uses 5 x Pioneer magnetics power supplies that I believe are 
> identical to those in the Sun E1.

"back in the day" I was a certified (not as an FE, though) in various ways 
for the E10k, E15k, and E25k. We had several at Oracle when I worked 
there. However, I don't remember that detail (the brand of the PSs). I'm 
sure you are right, though.

> Note - in the modern datacenter in the US it's not uncommon for 
> everything to be run on 208, but everything would run on 120.

Yep, that's my experience, too. Although many telco datacenters still use 
DC. They are funny like that.

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[ethan]

Right... and in my area (hardly unique, I'd wager), you cannot get
3-phase in residential areas.  The shared transformers on the poles
don't provide it and you can't pay them to add/change a transformer.
You have to be in a commercial area to get that.  Fortunately for me,
my tastes in minicomputers runs "small", so my largest machines have a
30A 110V single-phase plug (frequently to an H-861, but not always).


The Cray is single phase, the only thing I've ever owned that was 3 phase 
was the laser stuff. Now my solid state laser projector uses 100 watts and 
producsed half the power of the argon that used to take 3ph @ 30A (and 
still tripped the breaker sometimes.)


I've heard sometimes the utility will indeed give you 3phase but you have 
to pay them to replace the transformer and it's very very expensive. 
Normally it's people buying used milling equipment that are after it from 
my experience. There are rotary converters and solid state converters but 
probably not ideal for huge loads.


The Cray uses 5 x Pioneer magnetics power supplies that I believe are 
identical to those in the Sun E1. The smaller rack with the VME 
chassis and hard drives -- good chance the power supplies are okay with 
110/120v. The disk trays at least are just good quality SMPS that do 5/12 
in each drawer (was 4 x 9GB full height disk per drawer.)


The Pioneer Magnetics supplies that run the computational part are like 
48vdc out @ 5000W each so not sure if they would run on 120V but if so 
-- it would be a real high amperage load.


Note - in the modern datacenter in the US it's not uncommon for everything 
to be run on 208, but everything would run on 120.



--
Ethan O'Toole

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, Paul Koning wrote:
> Yes, and time dependent as well.  I grew up in Holland; in the 1970s, we 
> had 3 phase in our house because we had an electric cooking range.

As you probably know, that's not usual the setup in North America, even 
for folks with electric ranges.

> In the USA, if you're a home owner with a need for 3 phase power, you 
> probably have to get a phase converter.  Fortunately those are not hard 
> to get, and solid state ones (variable frequency motor controllers) can 
> be rather inexpensive.

I've been responsible for bringing 3-phase into several new buildings. 
I'd totally endorse a VFC in most cases (except that it's one more part to 
break if that's a concern). The reason is that the lowest cost I've seen 
in Colorado was $4500 and the most is $7000 from Xcel. I've *never* heard 
of them simply saying "Oh your old transformer will handle that just 
fine." YMMV

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, Paul Koning wrote:
> It all depends on what you're comfortable with.

My original point was that it's not trivial. I'd stand by that point no 
matter how comfortable someone is with the install. Of course, even that 
is subjective, I suppose. If you have tons of time, money, and you were 
born with rubber duck feet, okay, sure, it's trivial for that particular 
human-duck hybrid. :-)

My real point is that if someone thinks they are just going to un-do a few 
screws on the breaker panel, slap in a 30A breaker, and they are done: 
that's not realistic. That's kinda how using the word "trivial" struck me 
along with the original description, at least. Maybe I'm over-thinking it.

> There are plenty of books explaining to homeowners how to wire outlets, 
> add breakers, and even larger scale stuff like replacing whole panels.  

Perhaps it wasn't obvious, but I've also done this type of work myself 
before, IRL. I choose not to use as much jargon, but that does not mean 
I'm speaking about hypotheticals. Personally, I don't need the Amazon 
book, though others might appreciate that. Again, I wasn't saying, "OMG, 
that's impossible!" My points were, simply "It's not trivial" and "It's a 
tad bit dangerous to trivialize it.".

> Yes, it takes time to do it right, and installing conduit and thick wire 
> demands some muscle.  Clearly, it's not for everyone.

I think most able-bodied folks would have the "muscle" to do it. It 
doesn't require winning any strongman competitions. No matter if you are a 
skinny little waif like me or some bodybuilding strongman, as I'm sure you 
all are. The issue I was bringing up wasn't despair at the inhuman 
physical strength required (joke!), but that it's going to take time, 
energy, and money... ie... subjectively non-trivial resources. 

To your point, it's definitely going to be cheaper to do it yourself 
versus using a licensed electrician, and it's not black magic.

> Then again, neither is carpentry, or plumbing.

Fair enough, but there isn't as much of a chance for 
instant-electrocution-death involved with plumbing and carpentry. Putting 
in 3-phase 208 isn't rocket science, but it can definitely kill you, burn 
your house down, or ruin your gear if you do it wrong. Of course, plumbing 
and carpentry done wrong could eventually flood your house or cause it to 
fall down in some extreme cases, too. The results just *usually* aren't 
quite as immediate and dramatic as electrical mistakes are.

> Personally, I will readily do electrical work, plumbing on a more 
> limited basis, carpentry hardly at all.

To your point, I'm quite the opposite. I'm a woodworker and setup to do 
just about any kind of carpentry imaginable. I don't have the butt-crack 
power (or the slightest detectable will) to properly plumb, that's for 
sure. When it comes to electrical work the issue is often permitting and 
inspection that are a problem in my area (building boom etc..) that makes 
it non-trivial. That and dealing with Xcel Energy, who could probably 
screw up a wet-dream, for the feeds.

> Other people have a completely different list of what they would 
> undertake.  For example, a lot of people would not tinker with software 
> or networks.

Agreed.

> This very definitely is an area where, if you're not 100% comfortable 
> with the job, the right answer is to pay to have it done.

Yeah, that's sort of my underlying point. While it might be easy to some 
people in terms of them not feeling intimidated by the task, it still will 
take some time, effort, money, and risk to your person (small or large 
depending on your levels of caution and experience).

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Paul Koning]

> On Jul 19, 2016, at 12:53 PM, Mouse  wrote:
> 
>> [...], especially since most electrical installations (even domestic)
>> are 3-phase.
> 
> This, I believe, must be location-specific.  In North America, it is
> usual for domestic electrical feeds to be only two-phase (that is, they
> are the two sides of a centre-tapped secondary - the two hot wires are
> 180 degrees out of phase with one another).

Yes, and time dependent as well.  I grew up in Holland; in the 1970s, we had 3 
phase in our house because we had an electric cooking range.  But ours was the 
only house in the block with 3 phase service; all our neighbors cooked with gas.

In the USA, if you're a home owner with a need for 3 phase power, you probably 
have to get a phase converter.  Fortunately those are not hard to get, and 
solid state ones (variable frequency motor controllers) can be rather 
inexpensive.  I have one for the 3-phase motor on the lathe in the barn.  $100 
for a 3 hp model, as I recall, though that may have been on sale.  VFCs should 
even work for 3 phase 400 Hz power, just the thing if you have a CDC Cyber 
tucked away in the basement.

paul

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Ethan Dicks]

On Tue, Jul 19, 2016 at 12:53 PM, Mouse  wrote:
>> [...], especially since most electrical installations (even domestic)
>> are 3-phase.
>
> This, I believe, must be location-specific.  In North America, it is
> usual for domestic electrical feeds to be only two-phase (that is, they
> are the two sides of a centre-tapped secondary - the two hot wires are
> 180 degrees out of phase with one another).

Right... and in my area (hardly unique, I'd wager), you cannot get
3-phase in residential areas.  The shared transformers on the poles
don't provide it and you can't pay them to add/change a transformer.
You have to be in a commercial area to get that.  Fortunately for me,
my tastes in minicomputers runs "small", so my largest machines have a
30A 110V single-phase plug (frequently to an H-861, but not always).

Code in my area allows for homeowners to do some of their own wiring,
but for projects larger than, essentially, outlet and toggle-switch
replacement, permits are required (but enforcement is, of course,
negligible unless something goes horribly wrong).  They did just amend
code locally to _prohibit_ landlords from self-repair of electrical
(and I think gas and plumbing) in rental properties, because of
several high-profile fires caused by inexpert work.  So you can work
on your own domicile, but not your tenants'.

-ethan

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Mouse]

> [...], especially since most electrical installations (even domestic)
> are 3-phase.

This, I believe, must be location-specific.  In North America, it is
usual for domestic electrical feeds to be only two-phase (that is, they
are the two sides of a centre-tapped secondary - the two hot wires are
180 degrees out of phase with one another).

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Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Christian Corti]

On Tue, 19 Jul 2016, Swift Griggs wrote:

The photo of that unit is entertaining. Whoever buys it will need to setup
3x 30A 220v outlets. That's going to make some licensed electrician very
happy.


Why? 32A 3-phase CEE connectors (the red ones) are very common, especially 
since most electrical installations (even domestic) are 3-phase. We have 
several in our museum, for example for the IBM 1130, the IBM 3340 disk 
drives and the three-rack HP system. You can also have 16A CEE connectors. 
Older installations may still have Perilex connectors.


Christian

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Mouse]

>> [...electrical wiring...]
> This very definitely is an area where, if you're not 100% comfortable with t$

Also, know your own limits.  A depressing number of people think
they're more competent than they are.

For example, I once had a neighbour who replaced an outlet in his
kitchen.  Turned off the breaker, removed the old one, put in the new
one, all very nice.  Turned the breaker for that circuit back on and
popped the service main breaker.

When I investigated, it turned out the new outlet still had the
bridging piece that shorts together the hots for the two outlets, and
this was a kitchen outlet and thus had separate circuits for each half
(and, as is often the case, they were on adjacent fingers in the
breaker box and thus on different phases).  So, of course, the new
outlet shorted the two hot phases together.

He didn't have the experience to recognize that those shorting pieces
exist, to realize that having four conductors instead of three coming
to the outlet - or its being a kitchen outlet - likely means the two
halves are on different circuits and thus likely different phases, or
the electrical understanding to put those facts together.  Which
wouldn't've been a problem, except that he thought he was fine - he
didn't bring me in until the main service breaker blew.  (He did,
fortunately, have enough sense for that to tickle his "something I
don't understand happened, call for help" reaction.)

I've been doing electrical work since I was maybe ten or twelve, when I
helped my parents wire the house they were building.  (My father
inspected my work first; then, this being de rigeur there-and-then, it
was inspected by a suitable authority.  Only then was it energized.)  I
don't hesitate to do routine house electrical work, maybe even
installing 30A outlets (though I'd make sure I looked up the
appropriate gauge of wire, and probably then used the next larger
gauge).  But I'd call in someone more experienced for something well
outside my own experience, like (say) dealing with 600/600 service.

I would say that, if you don't have a good deal of experience, find
someone who does to look over your work before you energize it.
Indeed, some jurisdictions require that for work done by unlicensed
persons - or at least used to, and I would assume some still do.  Even
if yours doesn't, it strikes me as the smart thing to do.

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Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Chuck Guzis]

On 07/19/2016 08:29 AM, Paul Koning wrote:

> Or hobbyist.  It's pretty trivial, after all.  If you live in a state
> where that's not allowed, that would be an issue.  But in NH, for
> example, homeowners can do their own electrical work.  I wouldn't do
> work on the meter box or other always-live parts, but anything that
> can be powered down isn't an issue.  For one thing, I know from
> experience that the fact someone has a license doesn't necessarily
> make him qualified to do electrical work.

A big concern would be getting basic service. I'd probably want a
secondary 200A panel for this, so the local utility would probably drop
a second transformer in my front yard (there's buried 12KV service
running up my driveway).   At least getting the extra panel would
involve a licensed electrician and inspections.

What would be a bigger concern is any HVAC needs.  The EPA has been
getting very predatory in their regulation of refrigerants and who is
qualified to handle them.  New proposed regulations are even more
stringent.  Life is very good if you're a licensed HVAC tech today.

--Chuck

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[ethan]

The other thing that's not trivial is that if you make a mistake, you will
likely either: 1. Die.  2. Burn down your house. 3. Ruin some expensive
and rare gear.
To me, that all sounds like a helluva pain and != trivial. Then again, I'm
a software guy. What do I know? :-P


Some fun pics:
https://users.757.org/~ethan/pics/office/IMG_0208.JPG
https://users.757.org/~ethan/pics/office/IMG_0209.JPG
30A 208 pulled from panel temporary to run argon laser. That was before I 
installed the 36KvA UPS. The little power supply in the back takes in 3 
phase 208A @ 30A and uses 2 gallons a minute of water, then drops like 70 
amps of DC at 60V or something to the laser. Something really nasty and 
lethal.


There might be other pics on my flickr of the Cray through the years at 
www.flickr.com/photos/ethanotoole


Had 4, sold 3, kept one for years... but it's up for sale cause 
hobbies/interests have changed a bit and storage space/power (still have 
more than my fair share of older computers.) I work near all the 
datacenters in Ashburn Virginia and I've been tempted to see about finding 
some space for it. The buildings often have a ton of unused space.




--
Ethan O'Toole

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Paul Koning]

> On Jul 19, 2016, at 11:58 AM, Swift Griggs  wrote:
> 
> On Tue, 19 Jul 2016, Paul Koning wrote:
>>> On Jul 19, 2016, at 10:54 AM, Swift Griggs  wrote:
>>> On Tue, 19 Jul 2016, et...@757.org wrote:
 Hmp. Well the Cray J932SE on there is legit :-)
>>> The photo of that unit is entertaining. Whoever buys it will need to setup 
>>> 3x 30A 220v outlets. That's going to make some licensed electrician very 
>>> happy. 
>> Or hobbyist.  It's pretty trivial, after all.  If you live in a state 
>> where that's not allowed, that would be an issue.
> 
> With respect, in my view, it's not trivial. ... That's real physical work 
> in my book and may non-trivially eat your weekend.
> 
> The other thing that's not trivial is that if you make a mistake, you will 
> likely either: 1. Die.  2. Burn down your house. 3. Ruin some expensive 
> and rare gear. 
> 
> To me, that all sounds like a helluva pain and != trivial. Then again, I'm 
> a software guy. What do I know? :-P

It all depends on what you're comfortable with.  There are plenty of books 
explaining to homeowners how to wire outlets, add breakers, and even larger 
scale stuff like replacing whole panels.  
https://www.amazon.com/Wiring-Simplified-Based-National-Electrical/dp/097929455X
 is one nice example, compact but densely packed.

Yes, it takes time to do it right, and installing conduit and thick wire 
demands some muscle.  Clearly, it's not for everyone.  Then again, neither is 
carpentry, or plumbing.  Personally, I will readily do electrical work, 
plumbing on a more limited basis, carpentry hardly at all.  Other people have a 
completely different list of what they would undertake.  For example, a lot of 
people would not tinker with software or networks.

This very definitely is an area where, if you're not 100% comfortable with the 
job, the right answer is to pay to have it done.

paul

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, Paul Koning wrote:
> > On Jul 19, 2016, at 10:54 AM, Swift Griggs  wrote:
> > On Tue, 19 Jul 2016, et...@757.org wrote:
> >> Hmp. Well the Cray J932SE on there is legit :-)
> > The photo of that unit is entertaining. Whoever buys it will need to setup 
> > 3x 30A 220v outlets. That's going to make some licensed electrician very 
> > happy. 
> Or hobbyist.  It's pretty trivial, after all.  If you live in a state 
> where that's not allowed, that would be an issue.

With respect, in my view, it's not trivial. As you point out, it's not 
actually allowed everywhere. Unless you are some kind of local townie who 
knows all the bylaws, you'd need to call your local building/permitting 
office to be sure.  I've lived in several places where it was definitely 
not allowed. In (al)most all places, you also need a permit to do the 
work, even if the PtB let you do it as an unlicensed hobbyist.  Also, any 
given rinky-dink home electrical panel box isn't always going to support 
30A breakers, might be out of room, or might not magically grant you the 
service-line current you may require (or in the case of 3-phase, the third 
phase you are going to need). You'll also need to find a route to get the 
proper sized wire in to the walls to feed the L6-30 or whatever 
receptacles you need, and install the outlets. That's real physical work 
in my book and may non-trivially eat your weekend.

The other thing that's not trivial is that if you make a mistake, you will 
likely either: 1. Die.  2. Burn down your house. 3. Ruin some expensive 
and rare gear. 

To me, that all sounds like a helluva pain and != trivial. Then again, I'm 
a software guy. What do I know? :-P

-Swift

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Paul Koning]

> On Jul 19, 2016, at 10:54 AM, Swift Griggs  wrote:
> 
> On Tue, 19 Jul 2016, et...@757.org wrote:
>> Hmp. Well the Cray J932SE on there is legit :-)
> 
> The photo of that unit is entertaining. Whoever buys it will need to setup 
> 3x 30A 220v outlets. That's going to make some licensed electrician very 
> happy. 

Or hobbyist.  It's pretty trivial, after all.  If you live in a state where 
that's not allowed, that would be an issue.  But in NH, for example, homeowners 
can do their own electrical work.  I wouldn't do work on the meter box or other 
always-live parts, but anything that can be powered down isn't an issue.  For 
one thing, I know from experience that the fact someone has a license doesn't 
necessarily make him qualified to do electrical work.

paul

Re: Cray J932SE (was Re: Straight 8 up on Ebay just now)

[ethan]

The photo of that unit is entertaining. Whoever buys it will need to setup
3x 30A 220v outlets. That's going to make some licensed electrician very
happy.


At the old small office I would just pop some breakers out and replace 
them with 2 pole 30 amp ones. When it was at the hackerspace there was 
some sort of fused cut off switch box on the wall, so I terminated a 
twistlock 30A and ran from there over to a subpanel that had the 3 
twistlocks for the Cray cabinets. I used A-B B-C C-A phases, so 208V each. 
I still have the subpanel and also a SquareD Powerlogic monitor w/ CTs and 
stuff that are mounted to the board that was with the system (might be 
visible in the picture.) I used a rubber core cable to run between the two 
-- which I originally had picked up to temporary run a 6 watt argon laser 
system with from time to time.


I originally had 4 of the J932SE systems, they were all HIPPI'ed together 
to form one system when used for power engineering for nuclear subs or 
something (Bechtel.) I dunno, it was all secret and they destroyed all of 
the hard drives and such from the system.


I never really thought the power was that crazy, I work in datacenters and 
these days there are single racks using twice what the Cray takes!



I worked with a Cray for a while of about the same vintage (pre-SGI Cray
running UNICOS and using an Sun SPARC Classic as a helper). It was a large
telco (MCI) and used for fraud-detection on calling cards. It was a
UNICOS-based system in a private Colorado Springs datacenter about two
blocks from some sort of manufacturing site for Cray (the building is on
Rockrimmon in Colorado Springs - the former home of the late Seymour
Cray).
I thought the whole rig was interesting, but it was barely a few weeks
before the whole company went through a near-death experience (two words:
Bernie Ebbers) and I walked across the street to another company and
scored a new gig (it was the late 90's, you could do that sort of thing
then). I never got a chance to get really proficient with the hardware or
with UNICOS. It was my singular regret with that gig, though.


Very cool! NASA LaRC had a J916 system used by some scientists for 
something, other than that I don't know of any others. I was a SGI guy at 
the same place, had some nice boxes.

Cray J932SE (was Re: Straight 8 up on Ebay just now)

[Swift Griggs]

On Tue, 19 Jul 2016, et...@757.org wrote:
> Hmp. Well the Cray J932SE on there is legit :-)

The photo of that unit is entertaining. Whoever buys it will need to setup 
3x 30A 220v outlets. That's going to make some licensed electrician very 
happy. 

I worked with a Cray for a while of about the same vintage (pre-SGI Cray 
running UNICOS and using an Sun SPARC Classic as a helper). It was a large 
telco (MCI) and used for fraud-detection on calling cards. It was a 
UNICOS-based system in a private Colorado Springs datacenter about two 
blocks from some sort of manufacturing site for Cray (the building is on 
Rockrimmon in Colorado Springs - the former home of the late Seymour 
Cray).

I thought the whole rig was interesting, but it was barely a few weeks 
before the whole company went through a near-death experience (two words: 
Bernie Ebbers) and I walked across the street to another company and 
scored a new gig (it was the late 90's, you could do that sort of thing 
then). I never got a chance to get really proficient with the hardware or 
with UNICOS. It was my singular regret with that gig, though.



-Swift