Engineers lead the search for life beyond Earth
Exploratory missions to study Mars, Europa, and signs from other star systems will attempt to answer the question: 'Are we alone?'
Seal Beach, CA--Man has always been fascinated with the possibility of extraterrestrial life. Nearly a hundred years ago, astronomer Percival Lowell, having spotted "canals" on Mars, elevated the topic from the metaphysical to the scientific. Today, renewed interest and funding has thousands of engineers and scientists designing machinery, sensors, systems, and spacecraft for exobiological excursions to several nearby planets and moons, as well as for examination of planets in adjacent star systems.
Much of this interest stems from a series of findings during the past three decades. Viking missions of the 1970s revealed no Martian canals, but returned photos of volcanism and massive surface features formed by water erosion billions of years ago. The Galileo spacecraft sent back startling data about possible liquid water on Jupiter's moon, Europa. And this past August, a team of scientists reported the possible discovery of fossilized microorganisms in a chunk of Martian rock that was blasted from the planet 15 million years ago and landed as a meteorite in Antarctica. Beyond our solar system, scientists estimate, lie about 50,000 Earth-like planets in our galaxy alone.
But "interesting findings" are not conclusive signs of life. To gather more evidence, NASA plans to launch a pair of flights to Mars every two years until about 2005, and Congress has promised $100 million a year in Mars money to pay for them.
Bring it back alive? One such program is the Sample Return Mission. Its goal: retrieve for study on Earth dirt, rocks, and core samples from three locations on Mars. These areas would be selected by studying data from the Mars Global Surveyor currently winging its way towards the planet. Onboard is a thermal infrared spectrometer that will help identify carbonate rock formations and an altimeter to map likely locations of sedimentary deposits.
The first mission would launch about 2003-05, with two follow-on missions at two-year intervals. Each would consist of an advance rover that would spend a year collecting samples. The rover would wait for a lander to arrive, transfer about one pound of samples, and then the lander would blast back to Earth.
Sample Return requires advancements in several areas, including:
• High-impulse, low-mass propulsion systems. "We're looking here for a 20% improvement in propulsion-to-mass ratio for traditional chemical engines," says Dan McCleese, leader of the Mars Expedition Strategy Group for NASA.
• In situ instruments. An example would be a microchip-based capillary electrophoresis instrument for amino-acid analysis that could be etched on glass just centimeters long. NASA's Microdevices Laboratory is working with Jeffrey Bada at the Scripps Institution of Oceanography in San Diego to make such a device.
• Lightweight, low-power excavation tools to get below the planet's radiation-sterilized surface.
• Long-range rovers capable of surviving for years on the surface.
Red rover. Such an exploratory vehicle might look a lot like Marsokhod. Built by the Lavochkin Association in Moscow, the roughly 150-kg rover has an articulated spine and rolls on six individually powered titanium wheels. "It can crawl like a serpent over rocks three feet high," says Daryl Rasmussen, an engineer with Ames' Intelligent Mechanism Group (IMG). Should all go as planned, Marsokhod will first fly as part of the Mars Together Program in 2001.
IMG engineers took the basic chassis and added U.S.-built electronics and avionics to create a world-class planetary rover. A three-joint robotic arm (McDonnell Douglas) can retrieve and manipulate rocks and tools while two of three video cameras, mounted on a 1.2-m tall mast, provide stereoscopic vision and "situational awareness." Camera signals feed through either a Matrox image digitizer for side-by-side grayscale shots, or a StereoGraphics processor to create 3-D color video for view-ing through CrystalEyes VR glasses.
Scientists can "pre-run" maneuvers on a computer workstation with a high-fidelity virtual re-creation of the rover and its environment. "They can perform a task virtually and then send the commands to the rover on Mars," says Rasmussen. With a 10- to 80-minute delay, real-time telepresence isn't possible.
Engineers expect to learn more about the planet's operational conditions from Sojourner, the small rover carried aboard the Pathfinder spacecraft scheduled to land on Mars July 4, 1997. Sojourner contains experiments to measure the effects of Martian dust on solar cells and determine the abrasive characteristics of the soil on machinery.
Watery moon. Mars isn't the only place scientists think could harbor life. On Jupiter's moon Europa, tremendous gravitational tidal forces might generate enough heat to create a liquid water ocean beneath the several-kilometer-thick ice crust. Henry Harris, a Jet Propulsion Laboratory technical staff member, thinks he has a way to sample that ice.
Called Ice Clipper, the proposal involves releasing a 50-kg, spherical, boron-nitride "impactor" from the spacecraft that is racing towards the moon at 8.6 km/sec. Just after release, retrorockets slow the spacecraft enough to miss hitting Europa by about 50 km. The impactor strikes the moon, shooting up a plume of debris that the spacecraft flies through, gathers, and returns to earth.
Refractory materials are captured by embedding them in a retractable panel of thick aerojel-filled pockets, while a sapphire plate coated with magnesium collects samples of volatile material. A shield protects the craft from the high-speed ejecta.
Challenges? Designing a laser pointer to target and track the impact location, and simulating a 19,000-mph impact with supercooled ice. "Nobody has ever tried to sample the surface of a planetary body by hitting it with something," says Harris.
Beyond Pluto. NASA's proposed Origins program, beginning about 2003, is charged with the formidable task of peering outside our solar system for habitable--or even inhabited--planets orbiting stars light-years away. Using a series of long-baseline, space-based interferometers (possibly as large as 1 km), scientists will analyze the spectrum of reflected light to measure the composition of these planets' atmospheres.
As with the Mars and Europa programs, Origins relies heavily on inferences and detective work; nobody expects to see crawling creatures. Says Dr. Firouz Naderi, Origins program manager at JPL: "You really don't have to sit down and split a pizza with an extraterrestrial to know that they exist. You can look for the telltale signs."
Center for Mars Exploration:
NASA Ames Intelligent Mechanisms Group:
The Origins program: http://www.hq.nasa.gov/office/oss/origins/Origins.asp
Jet Propulsion Laboratory:
--Mark A. Gottschalk, Western Technical Editor
Chrysler debuts new engine line
Auburn Hills, MI--Employing the aggressive approach that has marked their recent successes, Chrysler engineers have developed a new family of automotive engines in record time.
The company's aluminum V-6 engines, introduced in November, were developed in 98 weeks at a cost of about $625 million. In contrast, typical automotive engine-development programs take about two-and-a-half years and a billion dollars. "We designed these engines in the shortest time in the history of Chrysler and maybe in the history of the industry," notes Francois Castaing, executive vice president-vehicle engineering and general manager of powertrain operations for Chrysler.
The company's new engine line includes three models: a 2.7-l, 24-valve, dual overhead cam V-6; a 3.2-l, 24-valve V-6; and a 3.5-l, 24-valve V-6. The 2.7-l engine will first appear as the standard engine in the Dodge Intrepid and Chrysler Concorde for 1998. The 3.2-l engine will power the Dodge Intrepid ES and Chrysler Concorde LXi, while the 3.5-l will be used exclusively on the replacements for the Chrysler LHS and Eagle Vision.
To speed development and cut costs, Chrysler engineers employed a paperless design process. To accomplish that, they used CATIA-based computer design, predictive modeling technology, and rapid prototyping. They also used a simultaneous engineering process incorporating cross-functional teams from design, engineering, manufacturing and other disciplines. Result: The engines were designed and built in 98 weeks--about 26 weeks less than the norm for automotive engines.
Shortening the development time enabled Chrysler engineers to cut costs. The computerized design process also helped meet future emission regulations. "Because we are efficient and because we are fast, the customer benefits," Castaing says.
--Charles J. Murray, Senior Regional Editor
Little disk breaks data-density record
San Jose, CA--IBM has developed a 2.5-inch disk drive weighing less than 100 grams that packs 1.44 billion bits of data per square inch, company officials announced. Big Blue believes the disk, designed for a new generation of super-slim notebook computers, has broken the previous record for hard-drive data density.
Engineers used magnetoresistive (MR) head technology to design the 1.6-Gbyte Travelstar VP, just 9.5 mm thick. (The Travelstar 3XP hits 3 Gbytes of storage at a density of 1.35 billion bits per square inch.) The MR data-writing head allows data to be written more narrowly than with conventional thin-film inductive head technology; thin film is still used in the drive for reading data. "You want to write narrow and read wide," explains Mark Jones, program director, mobile business line management.
The 99-gram drive is a major weight reduction from the early '90s, when initial 3.5-inch hard drives for the first notebooks tipped the scales at around 300 grams. IBM's most recent 2.5-inch drive weighed 140 grams; Travelstar shaves off another 40.
"Notebook manufacturers want to increase features in a smaller size," Jones notes. "This is one of the contributors." About 90% of IBM's drives are sold to third-party OEMs, he says. dn
For more information on IBM drives, visit http://www.storage.ibm.com.
Truck caps pass tough certification tests
Mansfield, TX--Truck owners have long known the importance of high-performance truck caps that can withstand the rigors of the road and defy even the most demanding off-road terrain. However, until now, truck-cap owners have had to rely only on verbal assurance--or their own "pass/fail" experience--to ensure their truck cap was "tough" enough.
Enter the Brahma Tough Certification program. Introduced by ADUCO International Inc., the program tests truck-cap performance and provides a benchmark for the highest standards of materials and product quality in polymer truck caps. The tests simulate on- and off-road conditions and temperature extremes.
"While the style and appearance of a truck cap are critical, it is equally important that a cap withstand extreme weather conditions and has the strength to endure the jolt, twists, and torque of on- and off-road use," says J. Richard Negrey, ADUCO president. "We needed a material that would meet the Brahma Tough requirements of strength and functionality, while maintaining an attractive, stylish appearance."
ADUCO found that material in Centrex® and Lustran® ABS resins from Bayer Corp., Pittsburgh. The Brahma Tough tops are formed from a composite sheet of Lustran ABS 130 resin, with a cap surface of protective Centrex 401 weatherable polymer. The sheet, coextruded by Primex Plastics Corp., Richmond, IN, holds the key to creating the tough, yet flexible top that easily conforms to the shape of a truck bed.
The polymer caps are UV resistant, up to one-third lighter than fiberglass tops, and can be recycled, Negrey claims. The caps can be left unpainted or painted to match the color of a truck bed. Not only are they easy to maintain and clean with approved cleaning agents, they have reduced the potential for VOC emissions.
The Brahma Tough tests included a torsion test, during which the sample cap is bounced and twisted for up to 24 hours at room temperature. The sample is then thermocycled for 15 cycles in an environmental chamber that ranges from -40 to 160F over a 24-hour period. It is further tested for impact resistance to simulate the normal knocks a cap takes during loading and unloading materials.
ADUCO and Bayer also are investigating the possible use of polycarbonate glazing for truck caps. A new organic modified ceramic hard coat promises to dramatically increase the durability and abrasion resistance of polycarbonate windows. The material is expected to be introduced in mid-1997.
Computer connectors beat the heat
Harrisburg, PA--AMP Inc. has designed a one-piece, card-edge connector with the same one-to-one signal-to-ground ratio found in two-piece models. The design allows the connector to handle high signal speeds required by today's computer processors.
"As far as we know, AMP is the first to successfully make a one-piece, high-speed, card-edge connection, which is less expensive than the original two-piece connectors," says Jose Domingos, AMP's product manager of card-edge products.
In order to make the design feasible, AMP replaced liquid-crystal-polymer (LCP) materials with injection-molded Ryton® polyphenylene sulfide (PPS) supplied by Phillips Chemical Co., Bartlesville, OK. The housing's original design specified the LCP when production began. Because of dimensional instability problems during the high-temperature solder process, however, the LCP gave way to the Ryton R-44 PPS a few months later.
"Our major problem with LCP was its poor high-temperature creep characteristics," explains Doug Sarver, AMP's card-edge products engineering manager. "High-temperature creep is a real concern with connectors having a relatively deep card-slot depth and preloaded contacts."
The LCP-made parts distorted during infrared soldering. The interior walls for the card slot collapsed and prevented insertion of the daughtercard. Rejected connectors were scrapped, resulting in a large amount of costly, unusable parts.
On the other hand, the PPS resists high-temperature creep and can withstand the infrared heat used in surface-mount soldering--240 to 250C--to produce a more dimensionally stable part. Resistance to soldering heat, both wave and surface mount, is one of the many environments that AMP connectors must survive.
For example, the high-speed, standard-edge connectors are tested for long-term temperature resistance by being mated with test circuit boards and exposed to 105C for seven days. The PPS passed these tests without difficulty, and did not distort during the mounting process.
The multi-contact, edge-board connectors are used in high-speed, digital computer systems. These systems have printed wiring boards with two levels of 0.050-inch-centerline gold-plated pads offset by 0.025 inches. The connector's one-to-one signal-to-ground ratio is 40 signal lines per inch, with 500-ps edge rates and less than 10-ps skew.
Giant servomotors replace hydraulics
Rockford, MI--To coil the powerful springs for a truck's suspension, coiling machines must produce tremendous force. That's why most such machines typically use large hydraulic pumps and actuators.
Now, however, one firm has found a better way to coil steel wires for a suspension spring. JM Systems Corp., a maker of wire-forming and spring-coiling machinery, has introduced a spring-coiling system that employs giant servomotors instead of hydraulics.
The dc brushless servomotors, which may be the biggest in the world, power the systems that control the pitch, diameter, and feed rate of the springs. Using them, the machine can coil wire up to 0.75 inches in diameter, and produce up to 1,200 springs per hour.
Achieving such speeds, especially in high-force applications, would have been impossible with conventional servomotors. But the motors used on the new machine combine high torque capabilities with relatively low inertia, enabling the machine to reach higher speeds. "The better the torque-to-inertia ratio, the faster the machine can accelerate and decelerate," explains John Mitteer, president and founder of JM Systems Corp. "And the faster you can accelerate and decelerate, the higher your production rate." The motor's relatively low inertia minimizes overshoot and eliminates the need to take special steps to dampen the overall system, Mitteer says.
Key to the capabilities of the new machine was the development of the giant servomotors. Designed by engineers at Custom Servo Motors, New Ulm, MN, they measure 320 mm across and weigh 568 lbs each. Their peak torque rating is more than 12,000 in-lb and they are rated at 3,500 in-lbs continuous torque. To produce such high torque, the servomotors employ high-energy neodymium iron boron magnets. As a result, the magnets' weight and inertia are far less than they would have been if conventional magnets were used. "A conventional servomotor probably would have had at least four times as much inertia as our motor and probably would have weighed over 1,000 lbs," notes Bill Anderson, president of Custom Servo Motors.
The servomotors apply torque through a gearbox made by Cone Drive Textron, Traverse City, MI. Positioning accuracy of the tools, which must be maintained to 0.001 inches, is accomplished through closed-loop computer control.
By employing electric motors instead of hydraulics, Mitteer says he has eliminated potential noise, contamination, and maintenance problems. The machine will be used to coil springs for domestic automobiles, NASCAR vehicles, and railroad cars, as well as light and heavy trucks.
--Charles J. Murray, Senior Regional Editor
Silicone compound improves heat-resistance
Exton, PA--High temperatures, flame exposure, and molten splash can all mean trouble for industrial cables, hoses, and gas lines. Fyrejacket® sleeves and Fyretape® wrap from Bentley-Harris protect against such heat-related hazards.
Each product's design employs a substrate of woven fiberglass: hollow tube, filled tube, or flat tape. A specially compounded liquid silicone rubber (LSR) is coated over the top of the substrate and heat-cured. The LSR, from Dow Corning STI, Plymouth, MI, is a solventless, 100%-solids material with low flammability and a high limiting oxygen index.
The low surface energy of the cured elastomer helps Fyrejacket and Fyretape products shed molten glass or metal splash in difficult applications, such as steel mills and foundries. According to Bentley, both constructions are highly resistant to a wide range of solvents, fuels, and oils. And the products remain flexible at temperatures as low as -65F.
Fyrejacket sleevings are offered in two grades. Industrial class resists molten splash and temperatures up to 500F, while the aerospace class protects against short-term flame exposure and temperatures as high as 2,000F.
The LSR coating from Dow is a 30-durometer elastomer developed for use in high-speed injection-molding or extrusion processes. The material can be cured very rapidly and with little flash, holding tolerances and scrap rates low. It offers a 1:1 mix ratio and low viscosity for easy mixing and delivery, even at low injection pressures.
The solventless formulation of the silicone compound forms no hazardous by-products during the additional cure process, minimizing venting requirements and eliminating the need for solvent removal. The material also offers a long pot life of at least 24 hours after mixing at room temperature.
Getting a brake from the landfill
Carbondale, IL--Research-ers seeking ways to use Illinois' estimated 30 billion tons of recoverable coal have come up with some surprising results. For instance, it turns out that the properties of fly ash, a combustion byproduct, make it an excellent material for automotive brake pads.
That's the contention of Vik Malhotra, a professor of physics at Southern Illinois University (SIU). Malhotra's research, conducted under a grant from the Illinois Clean Coal Institute, concludes brake pads made from fly ash have better friction and wear characteristics than brake pads currently on the market.
"The combination of several combustion fly ashes makes the material used in the brakes superior to any synthetic material currently used in brake pads," Malhotra says. "In fact, it would be nearly impossible to duplicate the properties of fly ash for automotive brakes."
Malhotra and his graduate students mix 65 percent fly ash with other combustion byproducts and some non-waste materials. This mixture is poured into molds and allowed to dry. After curing in a hot-water tank, the long timbers are cut crosswise into sections that resemble hockey pucks. The pucks are machined into refined brake pads. Malhotra says this process can be used to produce pads that would retail for $15 apiece, about half the price of a conventional brake pad.
According to the Clean Coal Institute, coal-burning utilities in Illinois landfill three million tons of fly ash and other combustion byproducts annually. The organization funds many projects similar to the one at SIU in an effort to clean up coal's image. Gainful employment for coal byproducts can also be found in road-beds and surfaces, patio bricks, sewer tiles, and flower pots.
Fasteners aim at uninterrupted laptop performance
Melbourne, FL--Paravant Computer Systems' Rugged Notebook (RNB) 510 Series laptop computers operate in temperatures from 0 to 50C. A fully sealed aluminum alloy case protects against dust, dirt, rain, humidity, and salt. The computers are engineered to perform in areas subject to severe shock and vibration as well.
To ensure uninterrupted operating performance under these conditions, every part in each laptop is mechanically strapped, fastened, or soldered. Key to assembling the various components are more than 10 dozen PEM® self-clinching fasteners from Penn Engineering & Manufacturing Corp., Danboro, PA.
"Over the years, other fasteners have given me nightmare experiences by failing prematurely," says Walt Rankins, manager of mechanical engineering at Paravant.
The RNB 510 laptops feature five different types of PEM self-clinching fasteners, totaling 131 in each unit. Type PF32, low-profile, steel, self-clinching panel fasteners are installed at 12 external locations in 0.060-inch-thick aluminum. Rankin cites the fasteners' slotted heads, which enable loosening or tightening by hand, as a benefit should service be necessary in the field.
Fourteen Type BSOS, stainless-steel, blind, threaded standoffs support boards inside each unit. Their larger profile distributes pressure more evenly on the boards.
Meanwhile, 78 Type BS, stainless-steel, self-clinching, blind fasteners in four different thread sizes close off the display area and the main pc-board access area, hold the keyboard, and serve as points at the base of the unit that allow the entire computer to attach to a mounting bracket.
Twenty-four Type FHS, stainless-steel, self-clinching flush-head studs serve as alternatives to standoffs. They provide flexibility in mounting internal components without being noticed externally due to their flush-head assembly upon installation. Three Type SOS stainless-steel, thru-hole, threaded standoffs also mount internal components.
All the PEM fasteners bring the strength of threads and the durability of thread-mating surfaces to each unit's assembly, Rankins says. The hardware has proved so reliable, he adds, new RNB products will feature almost double the number of PEM fasteners: 256 in each unit.
Problem-solving software improves interface
Cambridge, MA--Developed in the former Soviet Union, Invention Machine Corp.'s IM Lab demonstrates that the thawing of the Cold War permits technology to flow both ways. The engineering support tool revolves around a vast database of engineering and scientific principles, each illustrated with diagrams, with an expert-system-like search engine.
While IM Lab contains volumes of information most engineers have never encountered, the Soviet-style interface required patience. The TechOptimizer module is Invention Machine's solution to the database sausage line. With it, engineers input a description of their problem as parameters using block diagrams and a Windows 95/NT interface.
TechOptimizer guides the user to construct a problem as a system of components, functions, and useful and harmful actions. This process in itself may suggest a solution. If not, TechOptimizer processes the input for querying any of IM Lab's so-called problem-solving modules: IM-Principles, IM-Effects, and IM-Prediction. A search may return a number of solutions based on physics, chemistry, thermodynamics, electromagnetic theory, or other laws of nature. Ideally, the engineer now has a better understanding of how to design a solution.
Code hopping foils car thieves
Auburn Hills, MI--Two of the Big Three U.S. automakers hope to take a bite out of crime by implementing Siemens Automotive's advanced vehicle immobilization system technology beginning with 1998 model year vehicles.
The system completely immobilizes a vehicle's engine if someone doesn't insert the correct electronically coded key in the ignition. It works by using a "rolling code." Each time the engine is turned off, the system instantly rolls to a new code that only the ignition key reads and remembers until the next time the driver starts the engine.
Another key to the system design is use of inductive energy to transmit the correct code throughout the system. High-tech scanning devices--common among car thieves--cannot read inductive code. Savvy car thieves have been using sophisticated scanners to decipher the codes of many of the electronically activated antitheft systems now in use.
Since its introduction in Europe in 1995, German insurance companies have attributed declining car-theft rates to this technology. In one year, 13,000 fewer vehicles were reported stolen--a 9% drop. In fact, German insurance companies specified in 1995 that car buyers purchasing new vehicles not equipped with Siemens' or a similar antitheft system be penalized by as much as 10% of the vehicle's replacement cost if their vehicles are stolen.
Stator encapsulation boosts productivity, reliability
Rockford, IL--Pacific Scientific engineers have developed an innovative new way to make stators for stepper motors that increases manufacturing productivity, while improving motor reliability. The trick: encapsulating the stators with a thermoplastic polyester resin, and performing the feat in a single injection-molding step.
By replacing time-consuming epoxy potting and other assembly operations, the encapsulation with 30% glass-fiber-reinforced Rynite® PET (polyethylene terephthalate), supplied by DuPont Engineering Polymers, Wilmington, DE, takes care of three key stator functions:
• Protecting the stator windings against vibration as well as from contamination by foreign matter.
• Forming an integral end bell with integral provisions for the way encoders are mounted.
• Enclosing lead connections in a rugged, long-lasting housing.
However, the benefits don't end there. "Changing from epoxy to Rynite gave us a dramatic reduction in cycle time," says Brad Trago, an engineering manager at the Pacific Scientific Motor and Controls Div. Potting with epoxy took two hours, including two curing cycles in ovens. Encapsulation with the PET takes just 45 seconds, according to Trago.
The change of encapsulation method also eliminated the need for 11 parts, including a printed circuit board, and simplified assembly. Winding leads are now welded to an eight-pin connector strip, instead of attached to the circuit board with eight insulation-displacement connectors soldered in place. Slot liners of Rynite PET, also used with the epoxy-potted stator, were modified to eliminate connector recesses.
In addition, thanks to the insulating effect of the encapsulation, the end bell, where the encoder mounts, runs more than 30C cooler than the aluminum bell formerly used. As a result, customers can specify lower-temperature, lower-cost encoders. Molded-in holes provide for press-fitting inserts to retain the encoders. This, in turn, provides greater flexibility in encoder mounting options.
"DuPont engineers helped us throughout the development process for the stator," Trago adds. "We came to them with a design concept, but with no experience in injection molding. DuPont's support was crucial in resolving problems during prototyping."
Pacific Scientific's Powermax II® motors are the most powerful NEMA 23 step motors available, Trago reports. They come in a full range of standard sizes and many custom configurations. Typical applications: factory automation equipment, packaging machinery, vending machines, and computer printers.
Decoder chip set spurs DVD-ROM drives
Irvine, CA--Toshiba has developed a DVD decoder chip set with a copy-protection processor that implements a scheme recently approved by the DVD Consortium to prevent "pirates" from illegally copying movies and other entertainment. Toshiba is also using the chips in its own DVD (digital video disk) players and DVD-ROM drives.
Hardware designers can use the chip set to implement core circuitry for a decoder board that would allow DVD-ready PCs connected to a DVD-ROM drive to play titles that use MPEG2 video compression. It supports all four DVD formats: single-sided, single-layer 4.7-Gbyte disks; single-sided, dual-layer 8.5-Gbyte disks; double-sided, single-layer 9.4-Gbyte disks; and the soon-to-debut double-sided, double-layer 17-Gbyte disks.
The chip set comprises:
• Copy-protection processor, which performs authentication and descrambles encrypted data from copy-protected materials.
• MPEG2 video decoder, which separates DVD program streams into video, audio, and sub-picture streams.
• Video processor, which performs sub-picture stream decoding and video mixing.
• NTSC encoder, which accepts decoded digital video and outputs it in NTSC digital format.
• AC-3 audio interface, which provides audio/video synchronization and audio stream buffering.
• Audio-output IC, which receives output from the AC-3 decoder and provides analog and digital audio output.
DVD-ROM drives and DVD players feature MPEG2 decoding of moving images with a resolution of 720×480 pixels and seamless replay of data dispersed throughout the disk. Interactive applications will include self-paced training/teaching programs, movies with multiple endings, and sports videos offering a choice of viewing angles and on-demand player profiles.
The DVD logic decoder chip set costs $75 each in 1,000-piece quantities. Toshiba also offers a reference design for a DVD-compliant decoder board with a PCI bus interface, and an OEM kit that includes software drivers.