Posts by Charles E 97 publicly visible posts • joined 2 Jul 2009
I remember our office had a Vector Graphic MP/M system much like the one described here. Dumb terminals on desks, attached via RS-232 to the main computer, which had an insane amount of S-100 card slots and could run the new Corvus hard drives. Everyone ran Wordstar of course.
There's an infamous video demo on YT somewhere, a guy is monitoring a huge HDD RAID and sets up a live graph of error rates. He goes over and YELLS into the RAID rack and the error rate goes sky high! It settles back down and everything is (mostly) fine, but the error rate is still nonzero. Hey might be a good idea generally to keep sound levels down in the server room.
I remember attending a homebrew computer club meeting at MIT circa 1974 on this upcoming 8080A chip, and how much better it was than the 8008 which was unobtainable and you might be able to actually get your hands on an 8080A. Hey assembly and higher level languages? Shut up and take my money. I built an 8080A S-100 system, it's still operational. In college, I used the 8085 SDK boards in our microprocessor lab to control stepper motors and other small circuits, it had a breadboard built in. The 8085 was intended to reduce the cost of the support chip set and it was competitive with the Z80. But the whole 8 bit generation of processors quickly got skipped over for the 8086 and other 16 bit processors.
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.
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.
GIMP will never gain widespread acceptance, because the industry standard tools like CMYK separations, Pantone colors, etc. are all proprietary code and thus cannot be included in GNU-license software. Sorry, that's just a fact of life for professional graphics creators. Amateur software is only good for amateurs.
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.
Perhaps you should consider whether Parliament was trolling when it enacted The Dual-Use and Related Goods (Export Control) Regulations 1966, Category 9 - Aircraft, Space Vehicles, Propulsion Systems, and Related Equipment. I'm not certain what regulations would apply at the launch site in Spain, but I have contacted the Tripoli Rocketry Association (active in Spain) and asked them to evaluate the flight systems and launch parameters.
This isn't funny, Lester. Do you not understand what you are doing? This is no longer a paper airplane built from straws. This is a missile with military grade components. You have already shown the world how to build a radio operated computer controlled detonator. What do you think a rocket motor is? It's a stick of explosive. You've told people where to get these products, and shown your original research on how to get these detonators to work in a vacuum. The same device that can ignite a rocket motor in a vacuum could ignite in an oxygen-free environment like for example, the bottom of a gasoline fuel tank on a bus full of people.
Now you're getting ready to launch the damn thing. You've built a rail-launch system, just like the Nazis used to launch the V-1 buzz bomb. You've built a GPS guidance system that can guide a glider to specific coordinates, which could be an empty field in Spain, or 10 Downing Street. It has significant payload capacity, since it doesn't have to fly level, it can plummet to earth and merely use its fins to steer, like a GBU-27. There is almost no limit to payload, you can just add more helium balloons to compensate for the extra weight of a few kilos more RDX or C4. You almost have a TV guidance system like the AGM-65 Maverick missile, certainly your PiCam system can transmit enough live telemetry to allow you to watch through the nose cone and steer your missile to the target. Or maybe you didn't think of that. Like you haven't thought ANY of this through. If a bunch of idiots like you guys can build a military grade missile, just think of what the technology you have built and shown to the world, could do in the hands of the wrong people.
Do the world a favor, Lester. Scrap the missile. Burn it. Remove the detonator plans from El Reg's site. Try to erase all the evidence you were ever connected to such a stupid idea. Because when someone drops one of these things on London, MI5 is going to come looking for YOU.
The speed issue is trivial when it is dropped from above. You can name the aircraft after a bimbo and carry a toy as a payload, but it's still a standoff missile, and far more sophisticated than the guided glider bomb that sank HMS Egret.
Did anyone check with the MoD to see what they think of this project?
We have been discussing your flight systems elsewhere on the web, and I propose that you program your flight a bit differently and equip it with a payload other than the Vulturenaut.
Instead of launching the rocket at the highest balloon altitude, you should just drop it. Then let the autopilot systems glide it to the ground target. When the aircraft is within visual range of the target, fire the rocket, and detonate the C4 explosive payload with a proximity fuse when it hits the target. This would be like an Exocet cruise missile, it would speed up as it approached the target so it could not be shot down.
Then maybe you'll realize this isn't a toy and you are building a prototype cruise missile weapon.
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.
This whole LOHAN project is a classic case of Creeping Featuritis. The more features you keep adding, the less likely it is that ALL of them will work perfectly during unexpected conditions. And the way you are setting it up, every single feature has to work perfectly the first time. What could possibly go wrong?
I keep telling you guys, you should not attach the lines to the truss that way. It lets the truss roll around the axis of the top bar. Instead, you should turn it upside down and attach four lines, one to each corner. You will basically be making a pyramid of lines, four attachment lines leading to a central point. This will keep the truss from rocking back and forth, the four-point bridle will keep it stable. If you use the current method, it's going to be a problem during launch. There's no way to keep the direction of thrust perfectly aligned with the truss, so that will make the truss roll a bit. The plane could easily get snagged if the truss gets rotated or inverted.
Thanks, but I notice the article still retains the usage. Oh well, the story is water under the bridge by now.
But seriously, El Reg's headline writers can do better than that. It might have been preferable to use a headline like "Dem Chicks Lack Fizz" or something like that, rather than the GOP disparagement.
Please be aware that the accepted usage is "Democratic Congresswomen," not "Democrat Congresswomen." The usage of Democrat Party and similar constructions is a Republican idiocy, they refuse to refer to the Democratic Party by its properly accepted name. They would howl with anger if anyone used a similar construction like the "Republic Party."
You have succumbed to "Dog Whistle Politics." While you may not have understood anything was wrong with that particular usage, Conservative Republicans hear "Democrat Congresswomen" and hear the inaudible dog whistle, indicating the author is also a Conservative who is intent on disparaging Democrats.
Of course there is always the possibility that Mr. Page deliberately intended to disparage Democratic Congresswomen.
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.
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.
Actually mulching the grass clippings is really bad for your lawn. The decomposing grass clippings actually take nitrogen out of your lawn, which is the one nutrient the grass really needs most. Mulch is rich in nitrogen, but only AFTER it has decomposed.
If you want to mow a lawn properly, you have to catch the clippings. I used to mow lawns (with certification by a national lawn care company) and I always used a mower with a catch basket. I assure you that collecting and disposing of the clippings was far more work than actually cutting the lawn.
Now if you want a challenge, there it is. Set up your robot to catch and dispose of the collected clippings. And if you really want to do it right, use a reel mower mechanism.
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.
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.
Show me a 7 year old workstation-level windows PC that has performance that is still competitive with current models. How many times did you buy new PCs in the last 7 years? Do you even run high-performance apps like Maya that need a high end video card, or do you just run Microsoft Office?
I think this is Apple's implicit recognition that they are deliberately forcing customers to upgrade, to preserve the features they're using now (and paying for now).
I had to buy a new Mac just to preserve my mac.com email address that I've been paying $90/year since MobileMe first shipped, that must be at least 5 years ago. I had no devices that could run iCloud, I have a first generation iPhone and a PowerMac Quad G5 (a really expensive one that cost $4700, with developer discount, due to the insanely expensive Quadro FX4500 video card). Both of these machines serve me perfectly well. But no, Apple is forcing me to upgrade my Mac. If I had kept using my old Mac which runs MacOS X 10.5 maximum, I would have lost my primary email address.
So I've been paying for this lame MobileMe service for years, about the only feature I used (aside from email) was file storage on iDisk. And now that's gone. I feel like I was forced to buy a new computer, and I got a downgrade in services. Well at least I can still get my email on my old iPhone, even though it no longer syncs anything.
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.
Apple really had something that no other computer manufacturer had: a unified retail presence. It went way beyond a demo disk, it was a complete retail system from store fixtures down to the sales pitches. Their //c marketing packet for dealers changed the game completely. I will post one photo I scanned from their marketing materials, look at it and you will understand why I said this was the birth of the Apple Store.
http://i.imgur.com/sGCEz.jpg
There really was nothing like this in the retail computer industry, until Apple produced this campaign in 1984.
Alas, it was an inexpensive "credit card calculator" that fit in your wallet. But It was a nice gadget if you were a salesman like me that lived with a calculator in hand.
I published a few pages my sales newsletter, but some pages are incomplete first drafts. That's all I could find in my old paper records.
http://imgur.com/a/0P6mS
You can tell this document was written by an overworked, snarky salesman. I remember I used to get up in the morning, drink some coffee, drive to the store, then it was so busy all day that I wouldn't have time for lunch. Then I would get home late in the evening, too tired to make dinner, and I'd just flop into bed. A few days before christmas, I suddenly realized I had not eaten a meal for 6 days!
I note that the upgrade for MacOS X only supports Intel CPUs, running the installer says "PowerPC processors are no longer supported." This is stupid since there are millions of PPC Macs and leaving them vulnerable is just going to poison the entire Flash environment.
I guess Jobs was right, Flash Considered Harmful.
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.
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.
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.
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
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.
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