History of PostScript

PostScript is now on the market for more than 25 years. It has had a profound impact on the publishing industry and even today remains an important industry standard.

Part of this overview is based on “Accidental empires”, the book written by Robert Cringely on the personal computer revolution.

The dark ages

To appreciate PostScript, you have to know how the market worked before it became available. In the early 80′s, if you needed typesetting equipment, you went to Acme Typesetters, and they would sell you an Acme system with an Acme output device. Then you would follow at least two weeks of training to learn how to use the system. The Acme system would be incompatible with equipment from any other manufacturer. In most cases, it would even be difficult or impossible to exchange data with other systems.

If you owned a personal computer, you could hook it up to a dot-matrix printer that would output low quality bitmap characters. Graphics could be done but the quality was only acceptable to the nerds that bought computers in those days.

The beginning: Xerox

The history of PostScript starts at Parc, the research institute of Xerox. This is where many of the computer technologies we now take for granted were developed. The laser printer, the graphical user interface and ethernet are some prime examples.

One of the brilliant engineers working at Xerox was John Warnock. He developed a language called “Interpress” that could be used to control Xerox laser printers. He and his boss, Charles M. ‘Chuck’ Geschke, tried for two years to convince Xerox to turn Interpress into a commercial product. When this failed, they decided to leave Xerox and try it on their own.

Adobe is founded

John Warnock and Chuck Geschke named their company Adobe, after a little creek that ran behind the house of Warnock in Los Altos, California. You sometimes see it mentioned in wine guides on maps of Napa Valley where some of the most famous Californian wines are made.

At first, Warnock and Geschke thought of building a really powerful printer themselves but they soon realized that it would make more sense to develop tools for other manufacturers to control their printers.

It took Adobe 20 man-years to develop PostScript, a language that can be used to control output devices like laser printers.

1984: PostScript level 1

In 1984 PostScript was released. It was originally just called PostScript. ‘Level 1′ was added later to differentiate it from the more recent Level 2 upgrade.

PostScript is a very powerful language that looks a bit like Forth, another computer language. From the beginning, PostScript needed a pretty powerful system to run on. In fact, during the first years of its existence, PostScript printers had more processing power that the Macintoshes that were connected to them.

PostScript offered some huge advantages that other systems did not offer:

  • PostScript was device independent. This means that a PostScript file can run on any PostScript device. On a laser printer, you get 300 dpi output, while the same file gives you beautiful and crisp 2400 dpi output on an imagesetter. For users, this meant that they were no longer tied to one manufacturer and could choose the devices that best fit their purpose.
  • Any manufacturer could buy a license for the PostScript interpreter and use it to build an output device.
  • The specifications (syntax) of PostScript were freely available so anyone could write software that supported it.




PostScript takes off

PostScript was a pretty big gamble for Adobe and they might have failed to convince the market of its value if it hadn’t been for Steve Jobs from Apple Computer.

In 1985, sales of the Macintosh computer started to fall back and Apple really needed a killer application for its new baby. Steve Jobs liked the technology of Adobe, invested 2.5 million dollars in the company and convinced Warnock to create a PostScript controller for the Apple LaserWriter. This printer was similar to the HP LaserJet but the PostScript controller would allow it to output “typesetter quality” pages. The LaserWriter cost about US$7000. Today this may seem expensive (and it was!) but compare that to the first laser printer from Xerox, which, in 1978, cost US $500,000.

A computer linked to a powerful laser printer would not have made much of an impact but Apple and Adobe were fortunate enough to stumble upon a third partner, a small startup company that had created an application to utilize the Mac and LaserWriter to their full extent. The company was called Aldus and their software product was called PageMaker.

Desktop publishing was born and within a year, the combination of the LaserWriter, PostScript and PageMaker saved Apple and turned Aldus and Adobe into rich companies. Linotype was the first graphic arts supplier to recognize the value of PostScript and offer an imagesetter with its own PostScript RIP. Other manufacturers soon followed and PostScript quickly became the lingua franca of the prepress world.

1991: PostScript level 2

Around 1991, Adobe released the next revision of PostScript called level 2. It was a pretty significant upgrade that had been awaited eagerly by the prepress community.

1998: PostScript 3

For some obscure reason, Adobe preferred to call the latest update PostScript 3 instead of PostScript level 3. Compared to level 2, PostScript 3 seems like an insignificant upgrade. In some ways this can be understood since a lot of applications are still struggling to support level 2 properly.

2001: The great divide

The specifications for PDF 1.4, released in 2001, for the first time included a couple of functions that had no equivalent in PostScript: transparency and layers.

2006: The beginning of the end?

In 2006 Adobe announced the Adobe PDF Print Engine (APPE). This is a complete rewrite of their RIP architecture. Instead of relying on PostScript as its core page description language, APPE uses PDF. Designers can now export PDF files from a layout application such as InDesign. These pages are sent to a printer who uses a PDF based workflow system to check, trap and impose those pages. The PDF Print Engine is then used to create plate-ready data. In the entire chain, PostScript is no longer needed.

Hope you enjoyed the little history lesson. If you have any additional comments, let me know!

Peace out – Don



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