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Masato Sagawa and John Croat explain how they invented the neodymium-iron-boron permanent magnet

For sheer drama and resonance, few tech breakthroughs can match the invention of the neodymium-iron-boron permanent magnet in the early 1980s. It’s one of the great stories of corporate intrigue: General Motors in the United States and Sumitomo in Japan independently conceived the technology and then worked in secret, racing to commercialize the technology, and without even being aware of the other’s efforts. The two project leaders—Masato Sagawa of Sumitomo and John Croat of GM—surprised each other by announcing their results at the same conference in Pittsburgh in 1983.

Up for grabs was a market potentially worth billions of dollars. The best permanent magnets at the time, samarium-cobalt, were strong and reliable but expensive. They were used in electric motors, generators, audio speakers, hard-disk drives, and other high-volume products. Today, some 95 percent of permanent magnets are neodymium-iron-boron. The global market for these magnets is expected to reach US $20 billion a year within a couple of years, as the automobile industry shifts toward electric vehicles and as utilities turn increasingly to wind turbines to meet growing demand.

IEEE recently honored Sagawa and Croat by awarding them its Medal for Environmental and Safety Technologies at the 2022 Vision, Innovation, and Challenges Summit. IEEE Spectrum spoke with the two inventors, including an hourlong interview with both of them (only the second time the two have been interviewed together). They revealed their reasons for zeroing in on the rare-earth element neodymium, the major challenges they faced in making a commercial magnet out of it, the extraordinary intellectual-property deal that allowed both GM and Sumitomo to market their magnets worldwide, and their opinions on whether there will ever be a successful permanent magnet that does not use rare-earth elements.

John Croat and Masato Sagawa on…

You were trying to make a cheaper magnet, as I understand it. You weren’t even necessarily trying to make a stronger one, although that turned out to be the case. What made you think you could make a cheaper magnet?

John Croat: Well, the problem with samarium-cobalt…they were an excellent magnet. They had good temperature properties. You’ve probably heard the phrase that rare earths aren’t really that rare, but samarium is one of the more rare ones. It constitutes only about 0.8 percent of the composition of the ores that are typically exploited today for rare earths. So it was a fairly expensive rare earth. And, of course, cobalt was very expensive. During my early years at General Motors Research Labs, there was a war in Central African Zaire [now known as the Democratic Republic of the Congo], which is a big cobalt supplier. And the price of cobalt went up to something like $45 a kilogram. Remember, this was in the 1970s, so it basically stopped our research on samarium-cobalt magnets.

Masato, what do you remember? What do you recall of the state of the permanent-magnet market and technology in the 1970s in Japan?

Masato Sagawa: I joined Fujitsu in 1972, so that’s in the same age as with John. And I was given from the company to improve the samarium-cobalt magnet, to improve the mechanical strength. But I wondered why there is no iron compound. Iron is much cheaper and much more [available] than cobalt, and iron has higher magnetic moment than cobalt. So if I can produce rare-earth iron magnets, I thought I will have higher magnetic strengths and much lower cost. So I started to research the samarium-cobalt—or rare-earth iron compound. But it’s an official subject in Fujitsu. And I worked hard on the samarium-cobalt. And I succeeded in the development of samarium-cobalt magnet with high strength. And I asked the company to work on a rare-earth iron compound permanent magnet. But I was not allowed. But I had an idea. Rare-earth, iron and, I think, a small amount of additive elements like some carbon or boron, which are known to have a very small atomic diameter. I studied the rare-earth, iron, boron or rare-earth, iron, carbon. So underground, I did this research for several years. And I reached this neodymium-boron several years later. It was in 1982.

What was it that made you focus on neodymium, iron, and boron? Why those?

Croat: Well, of course, when samarium-cobalt magnets were developed, everyone in this field thought about developing a rare-earth-iron magnet because iron is virtually free compared to cobalt. Now, in terms of the rare earths, as I said, rare earths are not really that rare. The light rare earths, lanthanum, cerium, praseodymium, and neodymium, constitute about 90 percent of the composition of a typical rare-earth deposit…. So we knew at the start that if we wanted to make an economically viable magnet, both Dr. Sagawa and I realized that we had to make the permanent magnet from one of these four rare earths: lanthanum, cerium, neodymium, or praseodymium. The problem with lanthanum and cerium, as you know, the lanthanides are formed by filling the 4F electrons in the 4F series. However, lanthanum and cerium, the two most abundant rare-earths, had no 4F electrons. And we knew by this time, based on the work with samarium-cobalt magnets, that one of the things that you had to have was these 4F electrons to give you the coercivity for the material.

Can you give us a quick definition of coercivity?

Croat:Coercivity is the resistance to demagnetization. In a permanent magnet, as you say, the moments are all aligned parallel. If you put a magnetic field in the reverse direction, the coercivity will resist the magnet flipping into the opposite direction.

We knew that we wanted iron instead of cobalt…. And both of us set out with the intention of making a rare-earth iron permanent magnet from neodymium or praseodymium. The problem was that there was no intermetallic compounds available. Unlike in this rare-earth cobalt phase diagram—there was lots of interesting intermetallic compounds—the rare-earth-iron phase diagrams do not contain suitable usable intermetallic compounds.

In plain language, what is an intermetallic phase, and why is it important?

Croat: An intermetallic compound or an intermetallic phase is a phase with a fixed ratio of the components. Like, terbium-iron two has one terbium and two irons. And it sits on a crystal lattice in very specific sites on the lattice. You have to have that. That’s one of the quintessential requirements for any rare-earth transition-metal permanent magnet.

It provides the structure and stability you need or the reproducibility?

Croat: All of that. In other words, it’s the thing that holds the magnetic moment in place in the structure. You have to have this crystal structure.

So what was the solution?

Croat: The fact that there was no intermetallic compound was a baffling problem for some time. But then, in 1976, I and a couple of colleagues saw a paper by Art Clark. He was working at the Naval Surface Weapons Laboratory. He had taken a sputtered sample of terbium iron two [TbFe2] and annealed it at increasingly higher temperatures. And at about 350 °C, the coercivity shot up to about 3.5 kilo oersted. And we surmised, and I think correctly at the time, that what had happened was that during the crystallization process, a metastable phase had formed. This was exciting because this is the first time anyone had ever developed a coercivity in a rare-earth iron material. It was also exciting because of the fact that TbFe2 is a cubic material. And a cubic material should not develop coercivity. You have to have a crystal structure with a uniaxial crystal lattice, like hexagonal, rhombohedral, or tetragonal.

And so I started out with that thesis: to create magnetically hard metastable phases that are practical for permanent magnets. And by using rapid solidification, I started making melt-spun materials and crystallizing them. And it worked very well. I had developed very high coercivities right away. The problem with these materials were that they were all unstable. I started to heat them up at about 450 °C, and they would decompose into their equilibrium structure, and the coercivity would go away. So I began to add things to see if I could make them more stable. And one of the things I added was boron. And one day I found that when I heated my sample up containing boron, it did not decompose into its equilibrium structure. And so I knew that I had discovered a ternary neodymium-iron-boron intermetallic phase, a very interesting, technically important intermetallic phase. And it turns out that Masato discovered the same one [laughter].

Sagawa-san, you mentioned that you were interested in a sintering process, which was similar to the process that was then being used to manufacture samarium-cobalt magnets.... When you were working on a way to make neodymium-iron-boron magnets using sintering, did you encounter specific challenges that were difficult, that took a lot of effort to solve?

Sagawa: I was not able to give coercivity to the neodymium-iron-boron alloy. And I tried many processes. But the cost of sintering is good because to give coercivity to the alloy, you have to make a cellular structure in the alloy. So to produce cellular structure, the sintering is a very good way because first, you make single crystal or powder and you align the powder and then sintering. And during sintering, you form automatically cellular structure.

So I tried to form cellular structure. I tested many, many kinds of elements starting from copper. Copper is used in the case of samarium-cobalt magnets. And starting from copper, I tested many, many additive elements almost throughout the periodic table. But I was not able to give coercivity by making additional elements. And at last, I found a good additive element. It’s not another element—it’s neodymium itself. Additional neodymium gives home to cellular structure forming a grain boundary area around the neodymium-iron-boron particles. So I succeeded in giving coercivity to the neodymium-iron-boron by sintering and a neodymium-rich composition. And I succeeded in developing a neodymium-boron sintered magnet with record-high BH maximum [a measure of the maximum magnetic energy that can be stored in a magnet] in the world. It was in 1982.

This work is mostly happening in the late 1970s, early 1980s. You’re both working on almost the same problem on different sides of the world. Sagawa-san, when did you first find out that General Motors was also working on the same challenge that you were working on?

Masato Sagawa of Sumitomo [left] announced the invention of a revolutionary neodymium-iron-boron permanent magnet at a conference in Pittsburgh, in November 1983. At the same meeting, John Croat of General Motors announced the invention of a magnet using the exact same elements.Masato Sagawa

Sagawa: It was when I made the first presentation at the MMM Conference, Magnetism and Magnetic Material Conference, held in Pittsburgh in 1983.

Sagawa: November 1983. At the same conference, John Croat and his group presented a paper on the same neodymium-boron alloy magnets.

So for years, you both had been working on this problem, attacking the same problem. And you both found out about the other effort at the same conference in Pittsburgh in 1983?

That’s astounding. Did you talk to each other at that conference? Did you get together and say anything to each other?

Croat: I think we introduced ourselves to each other, but I don’t remember much more than that.

What do you recall, Sagawa-san? Do you recall any conversation with John at that meeting?

Sagawa: I remember that I saw John, but I don’t remember if we talked together or not.

Croat: I think it would have been logical if we did, but I cannot remember it. We probably considered ourselves competitors [laughter].

You both came up with independent means of manufacturing. General Motors came up with a technique called melt-spinning, and Sumitomo’s was a sintering process. They had different characteristics. The sintered magnets seem to have more structural strength or resilience. The GM magnets can be produced more inexpensively. They both found large market applications, somewhat different but still large uses. John, why don’t you take a crack in just explaining what their market niches became and still are to this day?

Croat: Yes. The rapidly solidified materials are isotropic. And during the rapid solidification process, you form a magnetic powder. That powder is blended with an epoxy and made into a magnet. But it turned out that these magnets were ideal for making small ring magnets that go into micromotors like spindle motors for hard-disk drives or CD-ROMs or for stepper motors. So that has—

Croat: For robots and things of that nature, servo motors for robots, but also spindle and stepper motors for various applications. And that has been the primary market for these bonded magnets because making a thin-wall ring magnet by the sintering process is very difficult. They tend to crack and break apart. But in contrast, the sintered-magnet market, which is much bigger actually than the bonded-magnet market, has been used primarily for bigger motors, wind-turbine generators, MRIs. Most of the electric-vehicle motors are sintered magnets. So again, most of the market is motors. But the market is bigger for the sintered-magnet market than it is for the bonded-magnet market. But there are two distinctly different markets in general.

Sagawa: I think one of the most important applications of the neodymium-iron-boron magnet is the hard-disk drive. If the neodymium-boron was not found, it would have been difficult to miniaturize the hard-disk drive. Before the appearance of the neodymium-boron magnet, the hard-disk drive was very big. It was difficult to lift by one person, 10 kilo or 20 kilogram or so. Now it becomes very small. And this is because of the invention of neodymium-boron sintered magnet which is used in the actuator motor. And also, the bonded-magnet neodymium is used in the spindle motor to rotate the hard disk. This was a very important invention for the start of our IT society.

Hard-disk drives contain several neodymium permanent magnets. There’s one in the spindle motor that rotates the disk, and typically two others in the read-write arm, also known as the actuator arm (the triangular shaped structure in the photo) that detects and writes data on the disk.Getty Images

You had little or no contact with each other until this meeting in Pittsburgh in 1983, by which time you’d already established all your intellectual property. And yet there was a long-running—well, not that long-running, but a patent case between General Motors and Sumitomo. John, can you start off and tell us a little bit about what happened there?

Croat: Yes. I guess we didn’t mention it, but both Sumitomo and General Motors filed patents shortly after the invention of this material, which turned out to be early 1982, apparently within weeks of each other. But it turns out, because of patent law, the way patent law is written, General Motors ended up with the patents in North America, and Sumitomo ended up with the patents for the composition neodymium-iron-boron in Japan and Europe. General Motors had the neodymium-iron-boron composition in North America. This meant that neither company could market worldwide, and they had to market worldwide to be economically viable. So they actually had a dispute, of course. I don’t know if they actually sued each other. But anyway, they had a negotiation. And I remember being part of these negotiations where we ended up with an agreement where we cross-licensed each other, which allowed both companies to market the material worldwide—manufacture and market the material worldwide.

But you could only manufacture and market your type of material, which, in your case, was this melt-spun, rapid—

Solidification. And Sumitomo had the sintering worldwide, North America, Asia, Europe, everywhere.

Croat: It turned out it was based on the particle size of the material. Sumitomo had the rights to manufacture magnets with a particle size greater than one micron, General Motors less than one micron.

Right now, of course, there’s a lot of controversy over the fact that an enormous amount of the world’s market for rare-earth elements is controlled by China, the mining, the production, and so on. So many countries, particularly in Europe and North America, are looking to broaden their base of suppliers for rare earths. But at the same time, there’s this existing market for these magnets. So is this having an effect of any kind on the future directions of R&D in permanent magnets?

Croat: I am no longer close enough to the R&D to know what’s going on, but I think there has been no change. People are still interested in making permanent magnets primarily containing a rare earth.

I don’t see how they’re ever going to get the rare earth out of a rare-earth transition metal magnet and make a good high-performance magnet. So the rare-earth supply problem is going to continue and will maybe even grow in the future as the market for these magnets grows. And I think the only way that they can overcome that is that Japan and Korea and Western Europe and North America will have to have some kind of government help to establish a rare-earth market outside of [China]. There are a lot of countries that have rare earths. India, for example, has rare earths. Australia, Canada have rare earths. United States, of course, has several big deposits. But what happened was, of course, the Chinese reduced the price to the point back in the 1990s and drove everybody else out of business. So somehow, some political will has to be put forth to change the dynamics of the rare-earth market today.

Sagawa: I think it’s impossible to produce high-grade magnet without rare earths. It’s concluded recently. There are very active research on an iron-nickel compound; it was promising. It has high-saturation magnetization and a very high anisotropy field. But I think, in recent research in Japan, it was concluded [that] it’s impossible to produce high-performance permanent magnet from this iron-nickel compound. And this is the last research subject on the rare-earth-free compound consisting of only 3D [orbital] -electron elements, iron-cobalt-nickel.

Glenn Zorpette is editorial director for content development at IEEE Spectrum. A Fellow of the IEEE, he holds a bachelor's degree in electrical engineering from Brown University.

This is a very nice article, especially since I know both Sagawa and Croat, and lived through this development.

It was very interesting to hear their conversation and how they remember those times.

There is one error: grand boundary should be grain boundary

It is disappointing that the editors chose to show bucky balls ( 5 mm diameter spheres) as an example of NdFeB magnets. Unfortunately, there have been many cases of children swallowing these magnets with dire consequences. Consequently, some of us have been working to get bucky balls removed from the market.

I'd suggest removing the bucky balls and just using the picture of the hard drive, or if you want something more up-to-date an EV drive motor.

Adobe’s founders and engineers tell a tale of software, stumbles, and serendipity

Time and again, in his earliest attempts at controlling laser printers, John Warnock got the message, “Page Too Complex,” from a recalcitrant machine. Any system he designed, he vowed, would have to have a “Print Anything” architecture. That goal led ultimately to a page description language called PostScript, today the de facto standard of desktop publishing.

This article was first published as "‘PostScript’ prints anything: a case history." It appeared in the May 1988 issue of IEEE Spectrum. A PDF version is available on IEEE Xplore. The diagrams and photographs appeared in the original print version.

Back then, Warnock already had a rough idea how to “Print Anything.” But later he ran into a different obstacle, when his employer, Xerox Corp., proved loath to support a truly standard language. So off he went, with Charles Geschke and several other colleagues, to found Adobe Systems Inc. in Mountain View, Calif. By that time, PostScript was only two major pieces of research away, although one—the development of type font algorithms—was “a research project that had to succeed,” says Warnock, and the other had been described as one of the world’s most difficult problems.

The rest is desktop publishing history. PostScript can truly do anything, though extremely complex images can take as much as an hour of computation time. It first appeared in the Apple LaserWriter, which was introduced in January of 1985. Today it has been adopted by 23 manufacturers of laser printers, with more still signing on.

This story is as much about luck and guts as about matters of principle and brilliant software engineering.

Still, this story is as much about luck and guts as about matters of principle and brilliant software engineering. It would have been quite different had Warnock and company not been in the right place at the right time to meet the right person.

The time was right because of the imminence of three hardware developments: the first low-cost, bit-mapped personal computer, the first low-cost laser printer, and a decline in price of high-density memory chips. And the right person was Apple founder Steven Jobs, who invented the first, hoped for the second, and told Adobe to tough out the third.

Software not directly tied to a specific piece of hardware.

A program that translates an instruction in the source code of a high-level language into machine language by deciding on the fly what machine instructions best translate it before moving onto the next instruction in source code.

A device that, like a xerographic copier, draws an image on a drum, but with a laser beam instead of lenses; applies toner to the charged image area; and transfers the toner to a sheet of paper, melting it into the paper to set the image.

A method of expressing the appearance of a printed image, including text, lines, and bit-mapped photographs.

Also known as reverse Polish notation, the appearance of operators after the data on which they are to operate; thus 2 + 2 becomes 2 2 +.

Today laser printers are rapidly replacing the daisy-wheel printers in the office, pushing out letter-quality type as their laser obeys the commands of simple software. But given more sophisticated software like PostScript, laser printers can do far more. They can print many different type fonts and make the letters dance around the page hand in hand with drawings and photographs. PostScript does all this implies—draws lines and curves, tilts text at arbitrary angles, or shades a photograph in various tones of gray. It is as complete and flexible a programming language as Pascal or C or Forth, having variables, loops, conditionals, operators, and routines and offering any number of ways to get the same output.

The PostScript program is created on the computer either by someone using the language or by desktop publishing software or other applications software that translates, say, the movements of a mouse into a PostScript program. (Other page description languages are optimized for one of these purposes, not both.) That program is sent over a local-area network or through an RS-232 port to the laser printer. There it is converted into instructions for the printer by the PostScript interpreter, software resident in ROM. On the same circuit board as up to 2 megabytes of ROM is a Motorola 68000 series processor, which executes the instructions and causes the pages to be printed.

Things were more elementary with the first laser printers, which were in regular use at the Xerox Palo Alto Research Center (PARC) in the mid-1970s. They were controlled by a printing protocol called Press, which was not a programming language but a set of instructions that sent image data to a printer in a steady stream. It handled letters and simple images well, but for anything more detailed, got the printer to return the message: “Page Too Complex.” Thereupon the typical PARC engineer would simplify the image.

But when Warnock, a computer scientist with a Ph.D. from the University of Utah, joined the center in 1978, he immediately began work on a new printer protocol. Six years of experience at Evans & Sutherland in Mountain View, Calif., had taught him where to start.

Adobe Systems founders John Warnock (right) and Charles Geschke visited Adobe Creek, inspiration for their company’s name. A dry winter has slowed the creek to a trickle, but the company has had anything but a dry year. The entrepreneurs in 1982 found Adobe a suitable name since the creek meandered near both their domes and, even more important, had none of the Qs, Xs, Ys, and Zs then popular with high-tech startups.

The PostScript program is created on the computer either by someone using the language or by desktop publishing software or other applications software that translates, say, the movements of a mouse into a PostScript program. (Other page description languages are optimized for one of these purposes, not both.) That program is sent over a local-area network or through an RS-232 port to the laser printer. There it is converted into instructions for the printer by the PostScript interpreter, software resident in ROM. On the same circuit board as up to 2 megabytes of ROM is a Motorola 68000 series processor, which executes the instructions and causes the pages to be printed.

Things were more elementary with the first laser printers, which were in regular use at the Xerox Palo Alto Research Center (PARC) in the mid-1970s. They were controlled by a printing protocol called Press, which was not a programming language but a set of instructions that sent image data to a printer in a steady stream. It handled letters and simple images well, but for anything more detailed, got the printer to return the message: “Page Too Complex.” Thereupon the typical PARC engineer would simplify the image.

But when Warnock, a computer scientist with a Ph.D. from the University of Utah, joined the center in 1978, he immediately began work on a new printer protocol. Six years of experience at Evans & Sutherland in Mountain View, Calif., had taught him where to start.

In 1971, Evans & Sutherland had undertaken to equip the New York Maritime Academy with a simulator for training harbor pilots. The trainees were to sit on the mockup of a ship’s bridge, surrounded by five 12-foot-high, 30-ft-long (3.6-by-9 meter) screens displaying a computer-generated representation of New York Harbor, complete with buildings, piers, movable buoys, changing weather conditions, and other ships to be avoided. The system had to produce images in full color for five projectors at 30 frames a second.

Evans & Sutherland had never produced anything as complex. It let time slip by until, with only one of the contract’s three years left, “everybody hit the panic button,” Warnock says. So to save time, the company had the hardware and software developed in parallel, the first in Utah and the second by a team led by Warnock in California.

The rush planted the first two seeds for what was to become PostScript. Obviously, a database listing everything in the harbor was both essential and would have to be built in total ignorance as to the hardware it would eventually run on. So Warnock’s team decided to invent a language unrelated to any computer. Only when the simulator hardware was ready would they build a compiler to translate the database into the appropriate machine language.

Meanwhile, feeding information about the harbor into the database proved arduous. Putting maps on a digitizing tablet and touching them with a stylus at numerous points was not so bad; but using a keyboard to enter the details—whether the point touched was a pier of a certain type or a building or an island—was slow going. To make this task easier, John Gaffney, one of Warnock’s group, spent a weekend writing a software routine that would generate the information about the objects from menus.

Because the PostScript Language treats text like any other graphic object, it can be scaled to any size and rotate to any angle. PostScript was the first page description language to be able to produce such a spiral of type.

By the time the harbor simulator was completed, only slightly behind schedule, Warnock had discovered how powerful an object-oriented language is. Unlike Basic or Fortran, say, which require the user to spell out every last instruction, it packs all those details into modules, or objects, which the user controls with just a few directives. Warnock had also discovered that making software device-independent “gives you a great deal of leverage and flexibility.”

Those lessons learned, his group turned to expanding Gaffney’s little interpreter into a full programming system for computer-aided design (CAD). In 1977, that project was released by Evans & Sutherland as The Design System. “It had an interactive, stack-oriented architecture,” Gaffney said, “with simple commands for pushing and popping arguments onto and from the stack and a rich dictionary for look-ups.” (Such an architecture stores data as it is received, stacking it like a pile of books. A command like “add” would “pop” the topmost pieces of data from the stack, act on them, and “push” the result back on the pile.)

Only one copy of The Design System was ever released, as a test bed for the final development, but the other company’s project director died and The Design System died with him. Warnock, however, took the stack and dictionary ideas—along with what he had learned from the harbor project—to PARC.

PARC was then using a programming language called Mesa. In 1978, soon after arriving at the center, Warnock persuaded another Xerox researcher, Martin Newell, to help him re-create The Design System in Mesa. The result, called Jam, for John and Martin, proved the concepts he brought from Evans & Sutherland were appropriate for laser printing.

Jam was object oriented and device independent, like the harbor simulator, and in some ways simpler than The Design System, because printing requires only two dimensions, versus CAD’s three. But it needed a few features, such as type fonts, found in neither of its ancestors. Moreover, Warnock recalls, “Xerox was using a different printing scheme on every printer. The Star workstations [then being developed] were crumbling under the load of trying to drive them all differently.”

So Warnock and a group of researchers headed by Charles Geschke set out to merge Jam with the older Press protocol into Interpress, a standard, device-independent language capable of driving all Xerox Corp.’s laser printers. Interpress was completed in 1981, but unhappily, the end was not in sight. Because of the compromise between Jam and Press, “the language became complicated in its redesign,” Warnock says. And Xerox begged the issue of standardization by producing several versions of the language, so the company’s older laser printers could run some form of it.

The commands of the PostScript programming language are optimized for graphics. This elongated word “Spectrum” was generated by the PostScript program shown below it. The first group of commands (red) identify a typeface from PostScript’s library of typefaces and enlarge it to 50 points from the 1-point size in which it is stored (in typesetting, there are 72 points to the inch). The next group of commands (blue) tells the laser printer at which point on the page to anchor the lower left corner of the word. The next command (yellow) stretches the typeface vertically, while leaving it unaltered horizontally. The final commands (purple) specify the letters to be drawn and order the printer to produce the image. A special program editor transmits the instructions to the printer.

Worst of all, to Warnock, was the insistence that printers always run at their rated speeds. Since a 20-page-per-minute printer could not produce anything very complex in three seconds, he was back facing his “Page Too Complex” nemesis. The constraint derived from the copier business, Geschke explains, where “pricing of leased machines was based on copies per day. But in electronic printing, in our opinion, function was most important, so there was a real variance between our and the Xerox position.”

All the same, in the belief that any standard was better than none, Warnock and Geschke began promoting Interpress within Xerox Corp. Eventually, they won—sort of. But Xerox added, Warnock recalls, “’We’re going to keep it a secret because it is so wonderful and if we publish it the Japanese might implement it before we do.’ “Gee,’ I said, ‘A secret standard—I find this a hard concept to understand.’”

Convinced that Xerox was making a mistake, Warnock and Geschke left PARC to implement their page description language once again, but this time within a corporation they controlled. With the help of David Evans of Evans & Sutherland and William Hambrecht of Hambrecht and Quist, a San Francisco-based venture capital firm, they wrote a business plan and incorporated in December of 1982.

They intended both to sell this setup as a turnkey system and to franchise the publishing equivalent of a one-hour photo store.

Desktop publishing, though, was not what Warnock and Geschke at first had in mind. The system they foresaw consisted of a workstation linked by a device-independent, page-description language like Jam to a laser printer for draft printing, a photo-typesetter for the final output, and whatever other output device they might later add. No other publishing package then available used the same software for different output devices. And they intended both to sell this setup as a turnkey system and to franchise the publishing equivalent of a one-hour photo store.

Adobe then consisted of Warnock, Geschke, and a core of other engineers hired from PARC: Daniel Putman, Thomas Boynton, and Douglas Brotz. As they planned to buy whatever hardware they needed after they had perfected their programming language, they focused first on Jam. They worked in C, on a VAX 750 running Berkeley Unix, to develop the language, and they tested in on a Sun workstation driving a full-size laser printer that they had borrowed from Digital Equipment Corp. “At that time,” recalls Putman, “most companies required that we spell our names and pay in cash, so we had to beg, borrow, and steal the tools to prototype PostScript.”

To avoid copyright problems, they licensed The Design System concepts from Evans & Sutherland. They were free to use their PARC research results, as those had been published.

For years theoreticians have suggested means of breaking images into their line segments, but their algorithms tended to fall apart when faced with difficult cases—large numbers of lines intersecting at a single point, for example (inset). The Adobe team says it has solved this problem with a proprietary algorithm with the results illustrated here. The image was created with Adobe Illustrator, a drawing program that runs on the Apple Macintosh personal computer, and was printed on the ColorScript 100, the first color PostScript printer, released in April by QMS Inc. of Mobile, Ala.

Warnock and Geschke were not close-mouthed about their plans, and soon not only Jobs heard (he was then chairman of Apple Computer Inc. of Cupertino, Calif.) but also C. Gordon Bell, then vice president of engineering at Digital Equipment in Maynard, Mass. Bell told the pair that six research teams at Digital had been trying for years to devise a decent means of driving its laser printers, and if Adobe could solve the problem, Digital would be interested in licensing the solution.

Jobs had been facing a similar problem. The Macintosh was well into development, but without a letter-quality printer would go nowhere in the business market. Daisy-wheel printers were out of the question, because they could not produce the bit-mapped graphics basic to the Macintosh. But Apple’s own engineers could not get high-quality graphics out of a laser printer in time for the Macintosh introduction.

Jobs suggested that Adobe become a software company, sell to manufacturers instead of at retail, and negotiate a licensing agreement with Apple.

Undeterred, Jobs and Robert Belleville, then director of engineering for Apple and now director of strategic planning for Convergent Technologies Inc., San Jose, Calif., had dreamed up the perfect Macintosh laser printer—one that could produce all the fonts in the world with no help from a disk drive. But they lacked “the slightest idea of how to do this,” says Belleville, until he ran into Putman at a cocktail party, heard what Adobe was doing, and brought Jobs over for a visit.

“I was overjoyed!” recalls Belleville. “Their system could do simple things fast and also do full graphics and scanned images. And when I saw font scaling was possible across such wide ranges, we were sold.”

Jobs suggested that Adobe become a software company, sell to manufacturers instead of at retail, and negotiate a licensing agreement with Apple. Adobe liked the idea, signed the agreement with Apple at the end of 1983, and much to Hambrecht & Quist’s surprise, showed a profit at the end of its first year.

Reimplementing the Jam language with its object orientation, stacks, postfix notation (in which operands precede their operators), and dictionary was relatively straightforward. Most of the research had been completed at Evans & Sutherland and at PARC. Basically all Adobe had to do was engineer it into a product, named PostScript after the postfix notation it uses and because it was to be the last thing that happened to an image before it was printed. Also, since the product had to “Print Anything,” it had to put functionality above speed and cost—the three factors traded off in the design of microprocessor systems like the one that would control the laser printer, explains Putman, now vice president of engineering at Adobe. Still, two key breakthroughs remained to be made.

One of them was creating the font algorithms, proprietary formulas for the creation of text. “Even with Interpress,” says William Paxton, director of advanced development for Adobe, “fonts were a wart on the side of an otherwise elegant design.” Interpress could do arbitrary transformations, like scale and rotate, on images, but in its early versions could not do them on bit-mapped text without degrading its quality.

PostScript, however, unifies text and graphics by storing the fonts as outline representations of the letters, not as bit maps. Back in early 1983, however, this unification was easier to propose than to realize. “Getting high-quality fonts from outline representations of characters was seen as an insoluble problem,” Warnock says, because it was hard to produce smooth curves of varying widths without jagged edges. Print quality seemed unobtainable from anything less than a phototypesetter.

But in mid-1983, Warnock says, he had an idea for a fundamentally new set of algorithms that might do the trick. His initial experiments promised success, so he set Paxton to refining the algorithms. The results are proprietary and are encrypted inside the ROMs that contain PostScript instructions because this font technology is the key distinction between Adobe’s product and others.

So successful was Adobe’s solution to the font problem that Linotype, Letraset, and other owners of the most popular typeface designs were willing for the first time to license the outline representations of their typefaces. No earlier technology had done them justice. (Ironically, Adobe is now licensing its font technology to Linotype, and Linotype is converting its entire library of some 2000 fonts into PostScript representations.)

Adobe’s other technical breakthrough is the algorithm, called Reducer, that breaks down complex shapes into simpler ones easier for PostScript to describe. Such an algorithm is a key component of any graphics language, and theoretical papers about a universal form of it were numerous: but, says Brotz, “they tended to gloss over the hard cases that arise in real applications—figures with large amounts of data and multiple intersections at the same point, for example.” So when the page printed, certain images would come out badly fragmented or warped, violating Adobe’s “Print Anything” rule.

“About a week after I had joined Adobe in 1983,” Brotz recalls, “John Warnock mentioned this rather important algorithm that had to be written. And I, with no graphics background, volunteered. Several months later, older and wiser, I realized it truly was one of the world’s hardest problems.”

But Brotz did not give up, and he says, “We have now an exactly correct reducer algorithm. It is the heart of the graphics system in PostScript.” And a tally Brotz keeps reveals that no bugs have been discovered in the Reducer in more than two years.

“Warnock promptly labeled [the procedure] ‘Andy’s Stupid Input Device'....[but] it turned out that Andy’s Stupid Input Device was the lowest common denominator and all the special-case code could disappear.” —Douglas Brotz

Adobe had agreed to deliver its software for installation into the LaserWriter during the summer of 1984. But because of marketing and manufacturing concerns, the LaserWriter itself was to be introduced in January of 1985. So the Adobe engineers used the time to tighten the code (the final release contained some 200,000 bytes) and fine-tune the algorithms. They also made some more specific changes.

One had to do with handling input devices. As originally conceived, PostScript was to have been independent of the output, but not the input, device. Warnock had thought that PostScript, to take in scanned images, would need to contain information about a wide range of optical scanners. But Brotz, after programming the parameters of just two of many scanner types, realized that the task was not only horrendous and repetitive but ate up a lot of memory.

Andy Shore, an Adobe computer scientist, overheard him complaining one day and suggested writing a PostScript procedure that would pretend that it was an input device and spit out the image information in a standard format, regardless of the characteristics of the actual standard. Brotz did not think it would work and “Warnock promptly labeled it ‘Andy’s Stupid Input Device.'”

Still, Brotz thought it might be helpful for generating test patterns, and when he implemented it, “it turned out that Andy’s Stupid Input Device was the lowest common denominator and all the special-case code could disappear.” Problems arise only when the image data has been compressed for transmission or storage; the programmer then has to insert a routine to decompress the data before it is handed to the image algorithm.

Another improvement involved performance profiling—running various tests to see what frequently used functions slowed down operation. Floating-point routines were the chief culprits because they are computationally intensive. So the team took some of the algorithms for the common operations, such as breaking curves into vectors and drawing outlines, and rewrote them in less flexible fixed-point arithmetic. Now only when fixed-point arithmetic would be too imprecise does the interpreter call the floating-point routine.

“So with no loss of generality,” says Edward Taft, Adobe senior computer scientist, “we were handling 99 percent of the cases five times faster than we were before.”

To improve the other 1 percent, Belleville sent one of his engineers over from Apple—Jerome Coonen, a recognized expert in floating point. He optimized the algorithms so, Taft says, “whereas formerly an algorithm required six multiplies, four divides, and three square roots, now it only required three multiplies, four divides, and some approximation of a square root.”

“We came from the school of thought that software is soft. So if you have problems, you just have another release. But Apple was telling us, ‘Hey, we always ship our system in ROM, why can’t you?’” —Douglas Brotz

Throughout the design of PostScript, speed was regularly traded off to ensure that any image would print. The group reasoned that if they built in all this functionality, they could eventually improve the performance; but if they left out functions, they might never be able to add them back in.

However, says Putman, sometimes they had doubts. So they designed a version of PostScript that spat out information as fast as the laser moved across the page. The expense of the frame buffer was eliminated—along with the ability to print pages too complicated for the software to process in time.

Adobe called this implementation Subscript, but dropped it after six months. As Taft says, “If you’re trying to promote a standard, there is nothing worse than issuing a subset of the standard. It means that all of the applications are going to be targeted to the lowest common denominator.”

Debugging throughout the project was strenuous because the Adobe team was “terrified of putting all this code out on ROMs,” Brotz says. “We came from the school of thought that software is soft. So if you have problems, you just have another release. But Apple was telling us, ‘Hey, we always ship our system in ROM, why can’t you?’”

In January of 1985 the Apple LaserWriter was introduced, virtually bug-free. In 1984, Adobe signed licensing agreements with QMS Inc., Linotype, and Dataproducts Corp. Today, even Hewlett-Packard Co., whose PCL page description language was one of PostScript’s earliest competitors, is among the 23 companies offering PostScript interpreters for their printers.

Although the Adobe group made some key technical breakthroughs, three other components were necessary to make PostScript a runaway success not just in low-volume professional publishing but in the high-volume office environment.

As noted earlier, one was a cheap laser printer. When Adobe was founded, the cheapest cost around $10,000. It also weighed as much as a desk, so that it had to be serviced on site and sold through a distributor, not on a cash-and-carry basis. Then Canon Inc., of Tokyo, Japan, introduced the Canon LBP-CX desktop laser printer, which, moreover, printed beautifully. “If it had been poor xerography,” says Paxton, “it wouldn’t have mattered how good our technology was.”

Also on the horizon was a bit-map-based personal computer—the Apple Macintosh. All previous low-cost personal computers had used character graphics, for which daisy-wheel printers made more sense.

“The projections were that the RAM prices were going to drop, but you had to have a very strong stomach to be able to go up to the wall and pray that the door was going to open.”—William Paxton

The third piece of luck was the decline in the price of memory chips. “We started this development on an uneconomic basis,” Warnock says. “The LaserWriter’s first controller needed forty-eight 256K DRAM chips, which up to December of 1984 cost about $30 each. That meant Apple would have had to sell that machine for about $10,000—but its computer cost $2400.”

But, with Belleville’s and Jobs’s strong support, the Adobe team bet that the memory process would drop. “Sure,” says Paxton, “the projections were that the RAM prices were going to drop, but you had to have a very strong stomach to be able to go up to the wall and pray that the door was going to open.”

Warnock comments, “Most companies will only deal with present-day technology and known costs. The brilliance of Steve Jobs is that he will say, ‘There will be this chip coming out at that price point at that time, and I will design my product to use it.’” And indeed, when the LaserWriter was announced in January of 1985, 256K RAMs cost about $4 each and the printer could be priced at $6995.

Today, some 40 companies have announced their equipment is compatible with PostScript and that their interpreters run faster and cost less than Adobe’s version. They cannot offer the same font library, but they say they have fonts and font algorithms as good as Adobe’s. At this writing, however, none of these companies had apparently shipped a PostScript clone to a customer, and they reportedly have found it harder to replicate Adobe’s work than they had anticipated.

When they do finally ship, and if they can interpret 80 or 90 percent of PostScript programs, Adobe is resigned to facing “good old-fashioned American competition,” says Geschke. The company has no patents to defend, only copyrights and trade secrets, so if other companies can reproduce Adobe’s technology, it has no legal recourse. “The most we can do is to continue to improve our technology,” Geschke says.

Adobe’s latest technical breakthrough, demonstrated in San Francisco in January, is a version of PostScript that controls images on a computer screen as well as on a printed page. Called Display PostScript, this product is the first to provide device-independent graphics for computer screens.

Display PostScript, like the original PostScript printer protocol, had a nudge from Jobs. His new company, NeXT Inc., Palo Alto, Calif., worked with Adobe to develop it, and it will be the graphics standard for all NeXT’s computers. Digital Equipment has already licensed Display PostScript for its DEC Windows workstation architecture. If other major companies follow, Adobe could be well on the way to setting its second standard.

Everything a programmer or user might want to know about the PostScript language is provided in “PostScript Language Tutorial and Cookbook“ and “PostScript Language Reference Manual,” both written by Adobe Systems Inc. and published by Addison Wesley Publishing Co. (New York, 1985). In addition, Adobe periodically publishes a newsletter, “Colophon,” with programming tips and news about PostScript products.

Interpress, the page description language from Xerox Corp.’s Palo Alto Research Center (PARC) that preceded PostScript in the laboratory but followed it in the marketplace, is described in the June 1986 issue of IEEE’s magazine, Computer (pp. 72-77). For more information on Xerox PARC, see “Inside the PARC: the ‘information architects,’” Spectrum, October 1985, p. 62.

“Window on PostScript” in MacWeek, Feb. 2, 1988, pp. 28-29, contains a discussion of competitors’ attempts to clone the language.

Update April 2022: While most home and office printers rely on other page description languages these days, PostScript remains the choice of graphics artists and commercial printers for its ability to accurately produce complex images. And the ubiquitous Portable Document Format (PDF) is based on PostScript.