Posts by Charles E

Ouch

I was on the receiving end of a problem like this. Our company purchased a new Agfa imagesetter, $200k if I recall. But upon delivery, they dropped it 3 inches off the truck tailgate onto our loading dock. The light-tight laser compartment was damaged and leaked light into the film compartment, every film we printed was ruined. The techs came out repeatedly to slap opaque tape over the area where they thought the pinholes were, but they could never fix it. I think the shipper's insurance must have eaten it, we eventually sent it back for a replacement. It sure was a nice piece of hardware, once we got a working unit.

Talon

Notice it did not so much fly as plummet.

Project Inferno

I think we all know where this is headed. Green slime starts coming out of the hole, turning the Professor into a Primord. Section Leader Liz Shaw must intervene.

Where are they?

I keep hearing about the new Pi models. Then I go to online sources and they're never in stock. Sometimes obsolete models are available, or higher end previous-gen models in expensive bundles. Or I could buy one on Amazon at a huge markup, from profiteers trading on scarcity. It seems like this "disruptive" computer has fallen to the same old greedy vendors and supply chain problems.

The 500 Mile Email

This sounds like the legend of the "500 Mile Email." Google it, it's hilarious (if you're a tech).

He should claim that due to the stress of the consequences of his actions, he has eczema and is suicidal. That legal argument seems to work.

Open the pod bay doors, Hal.

I've just picked up a fault in the AE-35 unit. It is going to go 100 percent failure within 72 hours.

Customer support, not Computer Support

You guys sound like the asshole IT manager at my university's computer lab, he wouldn't allow people to use this new software called NCSA Mosaic, he insisted this new "web browsing" thing was a fad and was a frivolous use of computer resources. Students should use Gopher instead.

Macs of that era were perfectly capable of storing both MacWrite and Word apps and running either one on demand. Word of that era was particularly heinous, MacWrite was far easier to use. But no, IT knows better than the users. They insist there is a PROPER way to use computers, which is not what the students want or need.

Design

Now that it's assembled, it looks even more like a JDAM.

http://navyaviation.tpub.com/14313/img/14313_41_1.jpg

Pretty short wingspan, has anyone calculated the glide slope? Or flight tested it, even tossing it by hand?

Just as last time..

This airplane did not "fly" so much as it "plummeted."

Almost my first computer game

I remember playing this on an early HP-3000 at my university when I was just a little kid, it must have been around 1973. I was pleased to see it was available on the Processor Tech SOL-20 computer I built from a kit in 1975. It was known as TREK-80, since it was ported to assembly language on the Intel 8080A processor. I remember being quite pleased to read in the manual that you could put a radio next to the computer, tune it to an empty channel, and the radio interference from the CPU would be picked up to make phaser sounds.

Here's a scan of the old TREK-80 manual, with a screen cap (a photo of the CRT screen).

http://www.dunnington.u-net.com/public/startrek/trk80.pdf

But I'm sure that wasn't the first computer game I ever played. I recall playing MoonWar on the PLATO IV system, long before the university got their HP-3000.

Imperial Units are god's law.

If god had meant for us to use Metric, he would have made the distance between King Henry's nose and thumb a meter instead of a yard.

Two different planes of existence

This story is so typical of journalistic excursions to Japan. It says more about the writer's inability to access Japan, than it does about Japan.

Pressure maintained?

I am curious if the low pressure in the vessel was maintained after the initial firing of the igniter, before the engine fired. The igniter carries a significant amount of oxidizer which enables it to burn in an oxygen-poor environment (like a vacuum). But this also means that when it fires, it releases a lot of gas, which would reduce your vacuum pressure. So while the igniter might burn, it still might not indicate whether the engine would fire at low pressure. The pressure might not be as low as you expect, at actual ignition time.

Why the fax is still popular in Japan

There are several reasons why the Fax is still popular in Japan. The CCITT Group 3 image standard used in Fax machines was designed to be just enough resolution to read handwritten kanji characters as used in Japanese. Before the advent of word processing, Japanese companies had terrible difficulty producing typewritten documents, so businesses usually circulated handwritten documents via fax. There's a really interesting article on El Reg somewhere, written by a really clever guy, about Japanese typewriters and word processing. It explains all this stuff, you ought to read it.

But the main reason why Faxes are still popular in Japan is not obvious: the cryptic Japanese street address system. Most businesses and homes have fax machines so they can send hand drawn custom maps to people who need to visit or make deliveries. Japanese street addresses are numbered by the age of the building. Street names are often unmarked and are often laid out in strange patterns. I recall buying my first Japanese Zaurus PDA in 1994 and being astonished that it had detailed maps of major Japanese cities stored in ROM, you could draw on them and fax them to people. This is why GPS systems were first popular with Japanese consumers. As GPS smartphones take over, and everyone can use their phones to access the internet for maps, the fax will gradually decline. But for most people, a fax machine is still easier.

C Rail - Apex Down

I concur with Ron B's description in the article of a truss configuration using an aluminum C rail, with the apex of the truss down and the flat side up. I have previously described the advantages of the apex down/flat up truss.

If the apex is up, that gives two attachment points to the balloon. This allows the truss to roll around the axis of the top rail. If the flat side is up, you could have four attachment points at the corners, giving additional stability along the longitudinal axis of the truss. It would prevent the truss from rolling.

Internet's First "Hall Of Shame" REVEALED

This is NOT the collection of web stars who've helped literally make the internet. Such a venerable institution has existed since the early 1990s, and apparently has now vanished from the web. It is worthy of preservation, but the only copy I could find is on the Internet Wayback Machine. So I submit to you, the "Kook Of The Month" gallery:

http://web.archive.org/web/20060719233552/http://www.lart.com/auk/whiners.html

Internet nut cases like Archimedes Plutonium, Doctress Neutopia, Terri Tickle, and RIchard Bullis did more to shape the modern Internet than Vint Cerf, Tim Berners-Lee, or Linus Torvalds ever did.

Tail configuration, etc.

I was surprised at this:

>For obvious reasons, the Vulture 2 must have a "V" tail elevon configuration..

No, actually it doesn't. The little tubes that guide the rocket down the rail can go on the bottom of the rocket, so the tail fins are facing away from the rail and truss.

Another note: I would not attach the lines to the truss at only two points, top and bottom. This will allow the truss to rotate or wobble around the axis of the top rail. Make a two point harness at the top, and another at the bottom, like a kite bridle. This will prevent the truss from swinging. I would actually invert the truss and put the apex of the triangle pointing down, next to the launch rail. This will allow you to put the attachment points on the four corners of a flat face of the truss, which is facing up, for more stability.

Some people have commented that the rocket could slip off the rail if it accidentally pointed down. There's an easy solution, you put a stopper on the rod, above the guide tubes, that is sufficient to keep the rocket from slipping off, but not sufficient to resist the force of the engine. That's tricky because if you make it too strong, the rocket will not get off the rail.

I also notice this new method of deploying the launch platform is exactly the same as the standard rockoon system that has been in use for over 50 years. I wondered how long it would take you to figure out that this was the best way to do it.

I am disappointed

As I was waking up and drinking my morning cup of coffee, with eyes still trying to focus, I saw that headline and I thought it read "Lenovo primed with keyboard-connectable toilet."

I am disappointed. That would have been quite a story.

Plural.

I wouldn't read too much into the iPhone(s) plural. That is a common enough way to refer to a singluarl item that ships en masse.

Hey, the new phone books are here!

Thin air

Ah, I see that someone with practical experience in building aircraft is noting the same problem I spotted and remarked on in previous LOHAN discussions: the thin air in the upper atmosphere is insufficient to provide enough lift, or control.

I think I know a time-tested way to work around this: drogues. Even Mars landers have used drogue chutes during the initial descent through the upper atmosphere, and Mars doesn't have much atmospheric pressure even at ground level. You wouldn't really even need a drogue chute for LOHAN, just something like a long streamer. I thought about it, you could put two drogue streamers, one from each wingtip, this would keep the nose pointed down and also prevent spinning. Then when the aircraft reached lower altitudes with enough air to actually fly, the drogues could be released, and it can level off and fly in a controlled path.

Drogues work pretty well, I used to build light model rockets that used drogues rather than parachutes. That worked perfectly in high winds, when you didn't want a long descent time to allow the winds to blow the rocket into the next county.

High Power Rocketry

It's good that you're going to the Scotland rocket event. You will undoubtedly encounter a niche in the rocketry hobby world, High Power Rocketry. I used to build rockets when I was a kid, back then, E F and G rockets were considered the top end, I recall building a small 2 stage F-D rocket that was designed to break the sound barrier with an audible bang (It worked but it flew so high it was unrecoverable). But now, things are way bigger. Hobbyists are using motors from small military missiles, and reloading them too. I was just blown away by what people are doing when I discovered HPR a few years ago. I just did a quick check of online vendors, now people are looking with disdain at puny F and G class motors, they're up to N and O class and above. And this high power requires a higher build quality too. You're basically building military class missiles.

Now the problem is, this stuff all requires licensing. I think you're going to need a consult from a licensed UK HPR builder. There is a hobbyist organization that could surely find an experienced HPR builder who would jump for joy at a chance to work on LOHAN. Check out the United Kingdom Rocketry Association:

http://www.ukra.org.uk/

Now here's where it gets serious. Or does it? Do you want to do a real rockoon and just skip the glider stuff? Because you could probably just do a regular HPR rocket and get the altitude you want, and descent could just be a regular parachute. These HPR guys are all experts in this stuff, they are good at tracking and recovery too.

Check out the IBM dot matrix printer

I had forgotten all about IBM's dot matrix printer until you showed that pic on the first page. That is an Epson printer, rebranded with an IBM badge. IIRC it had an IBM ROM so it could print the IBM PC extended character set and it responded accurately to commands like Print Screen. Epson sold their own version minus the IBM PC-specific code, it didn't quite work the same, it didn't print the ASCII graphic characters right, and I think the PrtSc didn't do a page feed right. But it was much cheaper than the IBM printer, so it sold like hotcakes. I think I recall selling only a couple of IBM branded dot matrix printers while I sold hundreds of Epsons.

No atmosphere = no aerodynamics

I am appalled at the designs with wings that depend on aerodynamic effects for lift. Remember that PARIS released at 89,000 feet, well into the stratosphere. There is insufficient air density at that altitude for a wing to create lift. That's why they use rockets for flight beyond the stratosphere. Rockets have fins to guide it through the lower atmosphere, but the fins have almost no effect once it hits the stratosphere. At that point, the rocket basically only has two forces acting on it, lift (the engine) and gravity. It takes careful design to get a rocket with an engine at the bottom to fly. You have to keep the center of thrust carefully aligned with the center of gravity.

So the LOHAN rocket stage cannot rely on wings during the boost phase. It's going to have to be basically a Congreve Rocket, the engine way up at the top, well ahead of the center of gravity. You could put a rocket on the end of a stick, like a bottle rocket, and it would perform adequately at stratospheric altitudes. The only force you can rely on at this height is gravity, you'll need it to keep the rocket oriented upwards.

Once the boost phase is over, the aircraft can basically tumble through the stratosphere. There is no air to provide lift and no drag that can orient the plane forward. It will need a wing design that has adequate lift, once it hits the denser lower atmosphere, and a good dihedral angle that can automatically correct a roll, and a good tail fin to correct spin. But none of those wing surfaces will have any effect at launch height.

IMHO the best design provided by readers is suspending an angled launch platform at the end of a 50 meter cable. This is enough distance to clear the balloon. Look at the wikipedia entry for Rockoon. It shows a photo of a Deacon Rockoon, it uses this design. It's been tested by real rocket scientists and it works. The wiki entry has a link to JP Aerospace, their Rockoon page has a similar design, and shows an actual launch photo.

http://www.jpaerospace.com/rockoons.html

The Plane that Fell to Earth

I suggest you first take a look at the flight plan, before designing the aircraft. This might address my criticism of PARIS which landed very close to the release point, indicating it did not really fly, so much as plummet. I noticed Samsung copied the PARIS flight concept as a commercial stunt, they sent up a balloon with hundreds of paper airplanes with memory chips affixed to them. They reported planes recovered hundreds of miles from the release point. This shows these simple fixed wing paper planes had a good glide slope, flying horizontally for a considerable distance. However, this is also a disadvantage in recovery, unless you have an international team to recover LOHAN across Europe (and perhaps the seas).

So I suggest taking some design cues from model rocketry. There is a type of rocket known as a "boost glider" that somewhat resembles my proposed design goals for LOHAN. A boost glider has two flight phases. First, the rocket boosts to a high altitude, and the boost stage burns out and ejects. Then the glider stage deploys, the wing shifts its aerodynamic qualities from vertical flight to glider. The key factor here is that in order to not chase the glider to a distant landing point, the wings are designed to put the glider into a gentle spiral, circling the release point. This is intended to maximize flight duration without flying the thing in a straight line into another country. This also has the advantage that the characteristics of the spiral flight can be fixed into the design without need for autopilots. In some cases, a simple aileron adjustment is all that is necessary to create the gentle turn required for a circular flight path.

The best boost glider kit I ever built will address some of the problems I see in Murray Pearson's proposal. His folding wing design seems to require a mechanism to unfold and fix the wings into flight position. The design I built was a kit from Estes, with a one-piece solid wing that rotated into place around a central pivot. During flight phase, the oval wing as inline with the rocket body. When the boost stage separated, it released the wing, which pivoted 90 degrees, pulled by a rubber band. This is a much simpler design than Pearson's which requires dual wing deployment. Vintage Estes model rocket plans are archived on hobbyist websites, but I was unable to find the rotating wing design. Still, that was perhaps more of a design stunt than would be necessary for LOHAN. Most boost glider designs have fixed wings that merely adjust ailerons during the flight phase. This would be sufficient for LOHAN, since the balloon will lift the glider during the initial lift phase, eliminating the need for aerodynamic characteristics needed for self-powered vertical flight. However, your proposal for a rocket powered initial flight stage would still require a stable flight platform. I might suggest using an example like the SEMROC Swift-BG design.

http://www.cdimodelrocketry.com/proddetail.php?prod=SEMROCKV27

It doesn't have any complex unfolding wing design, it's simple and looks effective.

Lag

I'm having trouble with lag lately. I'm still playing (get this, you won't believe it) Halo 1 for Mac. The main host is still running after all these years. But it seems like the only people that play it are in regions in South America, small "guilds" within a regional subnet but with high pings from any international site on the net. So what happens is the guild and the host are all close together with low latency, and everyone else who joins is a half second to two seconds behind. The guild kicks everybody's ass, especially the host who has home server advantage.

Copyfraud

For a further (and previous) analysis of this problem, you might look for my article on El Reg, entitled "Copyfraud: Poisoning the Public Domain."

http://www.theregister.co.uk/2009/06/26/copyfraud/

Thanks Tom.

I worked with DG Eclipse machines early in the 80s, my first real pro computer gig. Can you believe I was translating FORTRAN II legacy programs into the new 16 bit environment? Nobody in our office quite got the hang of their fancy Array Processor accessory.

I still remember one thing most vividly from the "Soul of a New Machine" book. He said he liked hiring Comp Sci grads straight out of school, because they didn't know what was impossible yet. Now that I'm an old veteran with 35 years of experience, I've tried to keep that attitude that nothing is impossible. If for no other reason, I really owe Tom West for that one idea.

Guy believes in God.

Guy believes HE IS God, at least where Apple's concerned. Guy has spent many years since his brief time at Apple, spouting his arrogant crap about how his "evangelism" saved Apple. But his turf, developer relations, prospered DESPITE Guy, not because of him.

Drone Attack Methods

This use of drones shouldn't be particularly surprising. That's what they were invented for. The first drone attack I heard of was by the Israelis, in the 6 day war IIRC. At that time, drones didn't carry weapons. So the Israelis sent a wave of drones at antiaircraft sites. The drones didn't have a very big radar signature, so they got fairly close, then the Egyptians thought they were an incoming attack wave of fighter-bombers. So like a 1/4 scale or less drone gets about 4x closer than a full size plane to give the same radar return.

So the drones get close, really close, and then the Egyptians turn on the SAM site radars to attack them. The Egyptians think they're shooting at a full attack wave, like 3 or 4x further away than the drones really are. At this point, the REAL attack wave is just popping up over the horizon, now they have fully illuminated radar sites to attack with HARM missiles. Brilliant.