CAD plus FEA equals time savings

By Laurie Ann Toupin Associate Editor

Every engineer is under pressure to speed design. The potential rewards: cutting design costs, beating the competition to market, and owning a new market for as long as possible. Part two of a four-part series examining engineers' concerns according to the Design News Simmons Study describes four ways to speed design without working yourself into a frazzle. Square D Co. sponsored this package of stories that shows how using CAD with integrated analysis tools, getting vendors to share design work, designing for manufacture, and using Internet tools can all help you work smarter.

Engineers Ken Lange, Rod Giles, and Paul Conley all needed to get their designs to production fast. For Lange, quick turnaround of the design of a new boat block meant it would be ready for yachts entered in the America's Cup race. For Giles, a 90% reduction in design time for a chassis meant keeping his client happy. And for Conley, cutting design time by 80% on a pump meant winning a new customer.

To speed design, each took advantage of a recent soft-ware trend: integrating CAD and finite element analysis (FEA) in one software package. This integration makes FEA programs easier to use and understand, allowing design engineers to run their own structural, dynamic, or thermal analyses.

Such integrated programs let engineers move FEA to the beginning rather than the end of the design cycle, where it has traditionally resided, says Victor Weingarten, president and CEO of Structural Research and Analysis Corp. (SRAC, Los Angeles). By giving engineers the ability to check their designs, the integration of FEA into CAD cuts time to market by reducing rework. It also results in fewer and more accurate prototypes and raises client confidence.

Lange, an engineer at Harken Inc. (Pewaukee, WI), a hardware supplier for the sailing industry, agrees: "The CAD/FEA combination shortens overall development time and reduces the number of prototypes."

Sailing through design. Using the SolidWorks CAD package from SolidWorks (Concord, MA) integrated with COSMOS/Works by SRAC, Harken drastically cut its design and optimization cycle. Harken makes blocks, travelers, furling systems, mainsail handling systems, and winches along with a range of complementary products for sailboats ranging from dinghies to yachts.

In 1996, the company introduced a new line of aluminum blocks, Black Magic, for large offshore cruising and racing yachts. The ropes from the rigging feed through these blocks for smooth raising and lowering of sails.

The design goal: Make the Black Magics the strongest, lightest blocks available. "Lighter boats accelerate more quickly," says Harken's Lange. These running backstay blocks are used in pairs to hold up the mast from the aft end of the boat, and tend to be the most highly loaded blocks on the boat.

The blocks incorporate CNC-machined cheeks and sheaves. High-strength plastic rollers bear the rolling loads in the block. A cage, which separates the rollers, reduces rolling friction and minimizes maintenance.

The Black Magic blocks' sculpted shape made early design analysis difficult. COSMOS/Works in conjunction with SolidWorks let Harken engineers quickly model and accurately analyze several designs before coming up with the optimum block. The result: a runner block that exceeded their expectations for weight reduction, strength, and ultimately sales forecasts.

When looking for analysis tools, Lange wanted an integrated product that used the same solid geometry as SolidWorks. "As we evaluated other software packages, the lack of integration and higher cost was a big barrier," he says. "We liked COSMOS/Works for its ability to associate loads and boundary conditions with a variety of designs and design changes. It also allows us to perform stress analysis quickly."

Hours instead of weeks. Pre-Star (Bedford, UK), a supplier of pressed and fabricated chassis suspension parts to automotive manufacturers such as Rover, Jaguar, and Ford, cut its design cycle by 90% using Pro/ENGINEER and Pro/ MECHANICA from Parametric Technology Corp. (PTC, Waltham, MA) to optimize a part even before it was shaped.

"The key to optimization is to examine the structure's performance early in the design cycle," says Rod Giles, design analysis manager at Pre-Star. "But our traditional process brought in structural analysis too late to have much impact on design. We wanted to reverse this situation."

Engineers got the chance to do that when a customer asked Pre-Star to increase the stiffness of the axle ends on a 4 x 4 vehicle. The bottom arm was bending elastically on rough roads and under continual severe impact, causing the drive shaft to move up. The drive-shaft movement caused oil-seal damage, and the leakage meant premature failure of the axles. Pre-Star engineers remodeled the original design in Pro/ENGINEER and optimized it using Pro/MECHANICA. The latter is simply a menu choice in Pro/ENGINEER, so there was no delay in translation and no need to wait until the end of the design process to analyze. Within four hours, they succeeded in increasing the stiffness of the part from 14 to 30 kN/mm. This task would normally have taken weeks or even months.

The new part, however, gained 2.5 kg. "We quickly realized that as weight increased, the stiffness rapidly tailed off--the law of diminishing returns," says Giles. "Seeking a better solution, we decided to start the design again from scratch."

Because the CV joint was rotational, the engineers wrapped the sides upwards to get a more effective section. This change increased the stiffness value to 38 kN/mm, while reducing the weight to 0.5 kg less than the original part.

Lubricating development. Lincoln Industrial designs and develops steel components for the pulp and paper, automotive, and mining industries. It provides lubrication systems such as pumps, controls, control valves, and metering valves.

The company never used FEA until two-and-a-half years ago when it decided to give Structural Dynamics Research Corp.'s (SDRC, Milford, OH) I-DEAS program a try. Usually projects took a year and half to finish. Today, using FEA early in the design cycle, Lincoln has shaved off more than eight months.

A customer asked Lincoln to customize a rotary pump in three months. If Lincoln met that goal, it would be able to market the pump for the customer. "We used SDRC to help us develop the concept, analyze the product for stress using the FEA module, produce drawings, and build a prototype all in two-and-a-half months," says Conley. "We supplied the customer with a fully operational pump within the time allotted."

Lincoln choose I-DEAS because it is a Windows NT-based, 3D solid-modeling program and structural package all in one. Plus, it can format AutoCAD drawings. "At the time we bought I-DEAS, only one other CAD package filled these criteria," says Conley.

The decrease in design time wasn't instantaneous. "It took us a while to get used to designing in 3D, to use the built-in library, and perform the structural analysis," he says. "We also had to get used to concurrent engineering." This was a total change in culture for the company. But today, Lincoln can do both design verification and validation well before the production phase.

"I-DEAS is a tool for the front end of the design cycle," says Conley. "If design time is going to decrease any more, it's the culture that needs to change. The tools are all in place. Engineers just need to get comfortable using them."

Vendors help share the load

By Charles J. Murray Senior Regional Technical Editor

Sparing no expense can help speed design, but it can also cause your next product to be a financial failure. That's what many manufacturers learn when they shorten their design cycles.

For that reason, design engineers are learning an important lesson: Let your vendors share in the cost, design work, and headaches. By taking advantage of a vendor's design expertise, product design can occur in parallel, thus speeding end products out the door.

A case in point: When a major computer maker recently needed a subassembly of three precisely spaced light-emitting diodes for a display, its engineers sought help from a vendor. The vendor, Bivar Inc.'s Optoelectronic Div. (Irvine, CA), shipped a custom-designed LED assembly to the firm within 48 hours.

That's a far cry from how long it would have taken if the computer manufacturer had purchased the LEDs, and then custom designed its own mounting system. Under those circumstances, the time from design to part shipment would have been 24 weeks or more, say Bivar engineers.

The LED assembly would have required all the conventional design and manufacturing steps of any major component. Those include: concept design with 2D drawings; 3D CAD modeling; stereolithography; creation of prototype tools and molds; testing; and full production tooling. In many cases, creation of single-cavity molds for prototypes can take up to 12 weeks. Similarly, full production tooling can take 12 weeks or more.

The computer maker simplified the process, however, by using Bivar's "Design Your Own LED Assembly" web page. Using the on-line process eliminated 3D modeling, stereolithography, and creating prototype tools and molds. It enabled engineers to test the design with real hardware, rather than stereolithography models.

For manufacturers, the key to the success of such systems is the ability to share design and prototyping costs with the vendor. Bivar, for example, keeps an inventory of 60,000 LED-mounting system components, thus eliminating the need for manufacturers to create dies and molds. "It's a matter of investment," says Anthony Vilgiate, vice president of optoelectronics for Bivar. "Why should the OEM invest in all that tooling when they can custom design their assemblies without it?"

Up-front effort. Vendors can also affect time to market by ensuring that the components they supply will fit within the OEM's manufacturing process.

Before Omron Electronics Inc. introduced a new line of signal relays, for example, the Schaumburg, IL-based firm checked with manufacturing equipment suppliers to verify that the relays would be easy to assemble. Omron engineers talked with makers of surface-mount assembly machinery to make sure the relays were compatible with surface-mount systems already in use. And they took their relays to vision-system manufacturers to ensure that the components would be compatible with high-speed machines employing machine vision.

Vendors rarely took such measures a decade ago. "Fifteen years ago, manufacturers would take your component and put it right into the assembly process," says Mike O'Brien, product marketing manager for Omron. "And it wouldn't take long before someone on the assembly line said: 'This is made from the wrong plastic. It's melting during reflow.' But today, by working with our customers' internal specialists, we come up with components that work from the start."

Omron also works with manufacturers' internal specialists to anticipate requirements for upcoming designs. The firm is currently developing 32-channel phone-line cards for companies that make telephone-switching equipment. By working in parallel with OEM designers--as opposed to working in series--Omron can substantially shorten product design times.

In one case, O'Brien says, Omron helped a telecommunications manufacturer cut its design-concept-to-market time from about four years to six months. O'Brien estimates that Omron's contribution accounts for at least a year of that three-and-a-half-year reduction. Similarly, the firm has helped manufacturers of refrigerators, stoves, dishwashers, and furnaces slash cycle times through up-front efforts.

Vendors are also helping to shorten cycle times by developing new software and virtual-reality design tools.

Dana Corp., for example, has formed a group that helps engineers lay out new production plants. The company says the ability to "see" the new plant before it's built encourages communication between OEM design engineers, manufacturing people, and shop floor workers. "It enhances the concurrent engineering concept," notes Ivan Stretten, manager of virtual engineering services for Dana Corp.'s Advanced Technology Resource Group (Ottawa Lake, MI). "Groups are talking to each other much earlier in the process than they normally would."

Dana recently laid out a new plant for a piston-ring manufacturer in Villanova, Spain. To optimize plant layout, the piston-ring maker sent a technical team to Dana's facility, where they "experienced" the plant in a visualization room equipped with a 10-ft screen and a high-end workstation capable of projecting 3D images.

During a two-day period, engineers made more than a hundred changes to the plant by viewing the virtual-reality image. "Ordinarily, those changes would have been made after the plant was built," Stretten says. "And by the time they were made, the company would have already experienced problems that slowed their time to market."

Experts say that such steps are all part of a new spirit of communication that's needed if manufacturers want to shorten their product cycle times. "Engineers can no longer be focused to a fault, not knowing what anyone else in their project is doing," says Jerry Collins, director of the Vehicle Development Process Center for General Motors. "They need to know their customers and suppliers. And they have to learn to work in parallel with them if they expect to cut cycle times."

DFM saves redesign time

By Gary Chamberlain Senior Editor

Want to drastically cut your design cycle, eliminate un-needed steps in your production operations, and get to the market ahead of your competition? Here's how three companies, sometimes with an assist from their suppliers, are using design for manufacture (DFM) to do just that.

In the competitive telephone market, manufacturers constantly strive to improve their products and reduce costs. Lucent Technologies (Middletown, NJ) accomplished both in the redesign and manufacture of its 8400 Digital Terminal Product line. The result: 11 fewer manufacturing steps and 46 fewer hours to produce a phone.

Two major technologies made the project work. The first, according to John Kowalik, technical manager at Lucent Technologies, was introducing laser marking to the factory floor. Here, the problem centered on how to efficiently build multiple versions of the same telephone set.

Feature buttons on the 8400 telephones have labels such as "hold", "conference", and "transfer". These labels are produced in different languages for different countries. In the beginning, the factory built different telephones for each language using two-shot injection-molded buttons. This complicated the final assembly line's scheduling efforts, lengthened delivery intervals, and required the stocking of many different sets of buttons.

"With laser marking, we now build a neutral version of each telephone," says Kowalik. "At the end of the assembly line, the laser-marking machine places the appropriate text labels on the buttons just before the telephones are packed for shipping."

The A-B Lasers LME-2RT system incorporates a servo-driven rotary table and a 40-inch dial plate with fail-safe features. The 65W Nd:YAG Dual-Head StarMark(R) laser features dual galvo heads, special fixturing, and a vision system for precision mark placement.

The second technology centers on a custom integrated circuit Lucent's Microelectronics Div. developed for the phone set. The new IC allowed Lucent to reduce parts count and cost by having a standard phone platform. In addition, the IC's flexible architecture lets the company quickly add new features to the phones as the need arises.

"Originally, a telephone required about 20 steps spread out over two days to produce," says Kowalik. "With our new manufacturing process, we now build the same telephone with nine process steps in two hours. Moreover, the process requires half the personnel and half the floor space."

Packaged on the fly. Factory engineering packaged for quality and cost-cutting provides another example of how companies can speed their design cycles and get ahead of the competition through DFM. In this case, an engineering breakthrough by The Trane Co. (Fond Du Lac, WI) and Square D (Chicago) allows variable-frequency drives and direct digital control systems to be integrated into HVAC equipment on the factory floor. It also cut Trane's production time for the units by 93% over a three-year period. In the bargain, Trane's new rooftop and air-handling systems perform better and last longer than their unpackaged counterparts.

"Packaged systems represent a quantum leap in terms of energy efficiency and ease of installation and maintenance," says Jerry Miller, product support team leader at Trane's Clarksville, TN, plant. The facility produces the Intellipak(R) and Voyager^TM packaged rooftop systems.

Before, customers had to develop field-engineered solutions for each project. The drive was installed in the equipment room and extensive wiring run to the roof. Then the controls were added and adjusted repeatedly to get the desired performance. The process proved expensive and time consuming. It also presented many avenues for manufacturing and installation problems.

"Now," says Miller, "It's a simple matter to hoist the packaged unit onto the roof, run your wiring to the main power source, install the duct work, and switch it on. Everything else--interlocks, control wiring, programming, and testing--has already been done."

However, building a packaged system required more than bolting the drive and control system onto a unit. It involved an engineering partnership between engineers at Square D's control plant in Raleigh, NC, and those at Trane's three plants.

The joint engineering program took six months and involved thousands of man hours to engineer, test, and prototype, according to Miller.

"It was a tough job, but seeing the business grow gives you immense satisfaction," says Miller. "The entire unit with all of its components is UL-listed from the factory, which is difficult and expensive with field-installed controls. It tells equipment buyers they're getting exactly what they specified and paid for."

Reproducible results. The transfer of accurate dimensions from design to manufacturing sometimes creates a costly bottleneck in getting a product to market faster. That problem plagued The Toro Co. (Tomah, WI), a producer of lawn-care products such as tractors and mowers, when sending dimensions for its welded mower decks and other steel items to the factory floor. The solution: adding an automated measurement system at the prototyping stage that not only produced precise dimensions but also sped the design cycle while cutting production costs.

Toro's problem centered on welded parts that shrink as weld beads cool. In addition, different welders weld differently. Tooling and fixturing must accommodate these variances.

The company's prototyping process involves five levels: Level 1 being a proof-of-concept model, and Level 5 being a pre-production run. In between, the design team gains information about how parts must be handled that are critical to manufacturability.

In the past, the development group started with a fixturing table and blocks to produce prototypes. The group took measurements manually using C clamps to hold the fixture in place. The procedure proved unsatisfactory.

"Things would move around," says welding technician Ron Woodard. "In the setup phase, the best tolerance that we could get ranged from 0.100 to 0.150 inch."

Such movements made it difficult to reproduce gains in flatness, part position, concentricity, or hole location from one prototype level to another. By the time an item reached the production level, tolerances could grow to 0.200 inch on a given dimension. To overcome this problem, Toro engineers replaced the fixturing table with the FaroArm measurement system and associated software from FARO Technologies (Lake Mary, FL).

Toro selected the FaroArm Bronze Series 06 model for the prototyping operations. The machine measures and digitally recreates the 3D shape of a solid surface. The system's CAD-based AnthroCAM(R) software captures data points from the arm. This enables Toro to digitally reconstruct the object in real time, and achieve single-point accuracy that ranges from 0.012 to 0.003 inch, depending on model size.

"Since we purchased the FaroArm, our productivity and quality has doubled or tripled," says Ron Ross manufacturing engineer. "We can now make production assemblies that repeatedly hit within a much smaller tolerance range."

Web connects engineers, resources

By Jean Young Gonzalez Western Technical Editor

Searchable parts libraries and electronic design management packages are just two examples of Internet tools that help engineers keep up with faster design cycles.

The 30-sec part. One of the founders of GlobalSpec.com (Troy, NY), an engineer at General Electric's Corporate Research and Development Center, was fed up with his inability to find products without tedious, manual catalog searches.

"When I designed engines at GE, I spent 20% of my time looking for parts," says John Schneiter, president and CEO of GlobalSpec.com. "I kept a whole cache of catalogs in a bottom drawer, and they were usually old and out of date when I needed them most."

This repeated exercise in futility prompted Schneiter to create an Internet-based engineering catalog library that provides immediate access to 100,000 parts. Starting first with sensor products and expanding into 96 different technology areas, www.GlobalSpec.com went live on the net in 1996.

"There is no reason why you can't find exactly what you need fast," says Schneiter. "We can cut the time a design engineer spends searching for parts by 98%."

The site, which is a soup-to-nuts repository of detailed product information, allows users to enter exacting part parameters to instantly access specifications and drawings organized by supplier name. Users can visit each company's showroom, contact the supplier directly via an e-mail hotlink, or browse each supplier's current catalog.

Unlike logging on to an on-line catalog, the user doesn't have to know which company's web site to visit. GlobalSpec. com browsers can zero in on multiple products from different vendors simultaneously, including sensors and instrumentation, motion controls, mechanical and electronic components, computer boards, and video/imaging technology.

However, users can't actually purchase parts on line--they still must call the manufacturer and generate a physical purchase order. And few CAD drawings and no 2 or 3D solid models are on the site. Adding these models would let engineers drop and drag parts right into their CAD packages, and--along with on-line part ordering--is the next step in GlobalSpec.com's evolution, says Schneiter.

Co-designing on the net. More companies are using the web to allow them to act nimbly and enable a totally dynamic design phase says human-factors expert Craig Hartley. User characteristics, functional requirements, design alternatives, final design concepts, reports, and test schedules can reside on an in-company intranet to speed cycle time. "Instead of distributing the drawing, distribute the URL," says Hartley, principal of Palo Alto, CA-based Human Factors Plus.

As Internet use increases, suppliers will get more involved in product design. "I think the design engineer will continue to do what he does but will work one step back in the supply chain," says Robert Neubert, national director of industrial and automotive products with Ernst & Young in Detroit. "Looking at an automotive Tier 1 supplier that makes brake assemblies, for example, that supplier will ask its supplier to design the spring assembly," he says. "This will require more trust and collaboration and more parallel design by multiple suppliers. The Internet is a tool that will help bring about this connectivity."

In another boon for collaboration, Immersive Design (Acton, MA) creates interactive product designs from 3D CAD solid-modeling software packages. These animations help people removed from the traditional design process--manufacturing, finance, sales, and marketing--communicate ideas and information about the product as it travels from supplier to customer during its life cycle.

What does a supplier of high-volume precision stampings and machined parts in Eugene, OR, need to know about working with a design engineer? A lot. Northwest Stamping & Precision allows designers to send an on-line request for quotation or a CAD file attachment via its web site www.nstamping.com for any stamped or machined part. Additionally, the company provides an applet-driven on-line sketch pad for engineers to draw and submit their concepts if they haven't yet committed them to paper.

Although web sites can speed design through information sharing, they don't yet allow for secure signatures, which would indicate final buy-off and approval of design drawings. When encryption standards slide into place next year, however, on-line signatures should become a breeze.

Preventing data deluge. Gone for good are the days when a single user operated a single machine running a single design tool. Now intranet-based, sharable electronic design tools let design teams work across the globe on the same project.

Library Studio, a customizable component data-entry and -management product from Viewlogic Systems (Marlborough, MA), lets companies create part libraries that global design teams can manage, publish, and access over the firm's own intranet. A vendor-neutral product, Library Studio helps provide what it calls "known-good designs" by reducing errors caused by wrong part selection. The product increases productivity by promoting design re-use.

Most product development and manufacturing processes use tools that come from many vendors, each dependent on component data extracted from a tool-specific library. As the number of tools increases, the number of libraries that must be supported increases, and the opportunity for component data inconsistencies and errors escalates. Library Studio ties together the various library representations of components that the automation tools require in design, analysis, and manufacturing.

"Viewlogic understands the global challenges and pressures systems designers face," says Paul J. Carlson, CAE/ CAD manager at 3Com Corp.'s Switching Systems Div. "Web-enabled tools from Viewlogic allow us to collaborate effectively and to develop products in today's market more efficiently."

New products help speed design

FEA for CAD

COSMOS/DesignStar is an FEA program compatible with all CAD programs, according to vendor SRAC. The software translates any CAD geometry regardless of modeling core--whether Mechanical Desktop, SolidEdge, SolidWorks, IronCAD, or Pro/ENGINEER--to Parasolid for meshing, thus a company with multiple CAD programs will require only one analysis program. Plus, COSMOS/DesignStar can run multiple analyses simultaneously, without needing the CAD program operating in the background. An engineer can design a model; apply loads, constraints, and material properties; and then perform stress and displacement, dynamic, and thermal analyses with a click of a mouse. Results are available within minutes.

Design-team networking

Reduce development and manufacturing time with ipTeam 3.0 product-team automation software from NexPrise Inc. ipTeam uses the Internet to coordinate people, information, and resources from the outset of a project. Decisions can be reached on-line through threaded discussions in the Internet Notebook, a central storehouse that captures all correspondence. Involved parties, worldwide, can view the same documents and notations simultaneously and mark them up in real time for the entire team to see. iTracker^TM securely monitors and tracks data residing in external systems and provides connections to legacy systems.

Manufacturing software

Xfactory from USDATA Corp. allows process engineers to rapidly model, implement, and maintain manufacturing production processes. Using Xfactory's graphical configuration, Manufacturing Execution Systems (MES) can be implemented up to six times faster than any other means, say company officials. This provides real-time work-order tracking, shop-floor inventory tracking, and equipment-utilization data as well as yield and throughput analysis. Xfactory includes real-time analysis tools for monitoring all aspects of production. Xfactory's Windows Distributed Internet Applications (DNA) architecture can help companies with multiple production facilities.

Fast-setting polyurethane

Parts-In-Minutes(R) from Ciba Specialty Chemicals' Performance Polymers is a fast-setting RP 6453 R/H polyurethane that demolds in less than 30 min.. Once cured, it exhibits performance characteristics that include the required UL 94 V-O rating at 0.125 inch, a heat-deflection temperature of 208F, a flexural modulus of 194,000 psi, and impact strength of 0.70 ft-lb/inch.

Quality-inspection system

Virtek Vision International Inc. has introduced the LaserQC^TM system for quality-control inspection and reverse CAD of 2D materials. The fully automated, self-calibrating system is said to provide faster 2D inspection than possible using such methods as hand-held gauges, coordinate measurement machines, or camera-based systems. The patent-pending process consists of a Virtek eye-safe laser projector mounted over a retro-reflective scanning table and powered by Virtek's proprietary software. The company claims that system accuracy is plus or minus 0.002 inch for quality-control inspection or for digitizing or reverse engineering. It can scan and process a typical 12x12-inch part in about 20 sec, and a 30x30-inch part in about 60 sec.

Fast-cure adhesive/sealant

Dow Corning Fast Tack RTV adhesive/sealant cures by reaction with moisture in the air, and releases no exotherm or corrosive byproducts. The material skins over rapidly and has a tack-free time of less than five minutes at 50% relative humidity. The high green strength of the one-part adhesive makes it suitable for high-speed assembly operations, particularly for electronic applications that require good mechanical properties and chemical adhesion. When fully cured, the material resists moisture, corona, ozone, and weather. It has earned the UL 94 VO classification.

3D design tool

Helix Design System, a mid-range CAD program from CSC MICROCADAM, can help 2D CAD users transition to 3D design in six months--less than half the time required to learn more expensive, high-end solid-modeling systems, say company representatives. Helix combines a user-friendly interface, training, and descriptive geometry techniques for product design, manufacture, and documentation. The product features autosolids, surfacing, raster engineering, and complete part rotation without added packages.

Microprocessor development kit

Engineers can quickly evaluate and develop designs for the MCF5206e ColdFire(R) microprocessor using the M5206eLITE development kit from Motorola. The $199 kit includes an evaluation board based on the MCF5206e, evaluation copies of third-party software tools, and software tools from Motorola that allow current 68K users to evaluate ColdFire processors using their existing code. With a terminal, the evaluation board can serve as a complete microcomputer system for evaluation, development, and training. Board peripherals include on-board ROM monitor, flash memory, SRAM, real-time clock, two serial ports, and space for additional I/O and up to 32 Mbytes of asynchronous DRAM.