Groundbreaking High-Speed Industrial Laser Printing System
Technological innovations in the 1960s and 1970s turned the world of printing upside-down. In 1969, engineer Gary Starkweather invented the laser printer (the Scanned Laser Output Terminal or SLOT) at the Xerox Palo Alto Research Center (PARC). This made it possible to output variable images to paper at speeds that could scarcely have been imagined before that point.
In 1971, Xerox chose Starkweather to head an ambitious project to merge this laser imaging technology with the extremely fast paper handling capabilities of their industrial copying systems in order to develop a high-speed laser printing system. This project took over five years and resulted in the Xerox 9700, a huge and expensive behemoth of a system which was the fastest printing system in the world at the time and remains, in its evolved form, as the benchmark for cut-sheet output.
Meet the 9700: Specifications
The 9700 printed at a resolution of 300 dots per inch* (dpi) and was capable of full-duplex (two-sided) operation. It had the ability to print landscape or portrait pages up to sizes around 9 inches by 12 inches (it was theoretically possible to go with bigger stock, but it was much safer to stick with standard US Letter or smaller) and could merge static forms with variable data. The system used bitmapped fonts, which were available from several sources (including Xerox, of course). 9700 systems could be outfitted to use magnetic (MICR) ink for printing checks.
The 9700 laser system was essentially two units: the printer and the terminal.The printer (about eight feet long, weighing hundreds of pounds) was further divided into three portions: the image module (IM), the laser module (LM) and the output module (OM). The IM featured a bin for 2500 sheets of paper and an auxiliary tray for 500 additional sheets. The auxiliary tray could hold a different stock, fed as required by the job, or it could be used as a reserve tray while the operator refilled the main tray. The IM housed the photoreceptor belt, fusers and paper-handling mechanisms.
The LM contained control electronics as well as the laser itself. The OM had two stacker output bins, each capable of holding about 2000 cut sheets. The input terminal was a stand-alone pedestal with a screen, keyboard, and 9-track (reel-to-reel) tape drive (later models added cartridge tapes to the system). The data stream could come from the tape drive or from an online source, usually a mainframe in the early days, but later systems could source from machines such as SPARCs or even from a PC (although
great ingenuity was required to make that latter arrangement work, if memory serves).
The 9700 paper-handling technology was appropriated from the Xerox 9200 line of high-speed copiers. It remains a model of ingenious engineering and has gone nearly unchanged into each subsequent generation of high-speed lasers. Running flat-out, single-sided (simplex), a well-maintained 9700 could print more than two pages per second.
These systems used Xerox's Job Source Language (JSL) for defining job functions. A JSL would set (among other things) fonts, forms, page orientation and whether the variable data was coming from an online source or from the printer's own tape drive. Subroutines, called CMEs (Character Modification Entries) could be introduced from the data stream for some pretty fancy functioning.
It was possible to create forms using Xerox's Page Descriptor Language (PDL). This slow and very labor-intensive process was quickly surpassed by a number of page design systems including Intran Metaform and Elixir.
Output Module Image Module
| |
_________________________ | |
/ /| --------------- ----------------------
/ / | { } { }
Reel-to-reel \/________________________/ | __________________________________________________________________
tape drive |\__________ | | / /| --------- Auxillary
| \ | | | / / | Paper Tray
| \ | _________ | | / / /|
| ( 0 ) | /________/| | |/ / / | }
| | | |=======| | | /_________________________________________________________________/ / | |
| | | |=======| | | | / / | / | |
| | | |=======|// | | / / |/ | |--------------- Main
| ( 0 ) | /wwwwwww// | | ______ ______ / / | | } Paper Tray
| |/wwwwwww// | | | | | | / / | /
| / | | | | | |/ / | /
| / | /| |______| |______/_____________/ | /
| | | / | | / | | / | /
|___________|_____________|/ | | / | | / |/
| |____|______/_______| | /__________________________|
Terminal | / | | /
Output |_____________| /
stackers { }
\
\
\
Laser Module
Trouble in Xerox Paradise: Quirks and Shortcomings
The 9700 operating system was simple and more than a little quirky. Input was entirely text-based and some of the commands and parameters were pretty bewildering. The file system had a quirk or two as well and file names were limited to six alphanumeric characters (and a three-character extension).
The use of reel-to-reel tapes was probably the best way to go in 1977, but the fact that the machines seldom had any other way to import data meant that forms, JSLs, and fonts had to be loaded onto tape and copied to the machine (a terribly irritating process when the poor forms designer has to make repeated simple revisions to a single form, load it to tape, copy to the laser printer ... again and again). Some later printers had floppy disk drives (8 inch SERIOUSLY!, later 5 1/4 inch) but they had the reputation of being so horribly unreliable that they were seldom used.
The 9700s printed in black and only in black, although an option called spot color was eventually made available for some machines—this allowed a single additional color on the page, but was a chore to work with. The 9700's graphics capability was extremely limited, both by the 300 pixel per inch resolution and also by the machine's own RAM. Even large fonts or the simultaneous use of several fonts (with bitmapped .FNT files, every different size of a typeface that was used had to be loaded separately) could overwhelm the rather meager memory of the machine, causing the printer to lock up, forcing a re-start of the job. An expansion for the graphics memory called GHO (Graphics Handling Option) was later made available, but it was not cheap.
Ultimately, however, the biggest drawback to the 9700 system was probably the price tag. From the few reliable figures I can find (and a lot of rumors I heard years ago), these systems cost as much as $500,000 US when purchased brand new and even rebuilt ones were over fifty thousand dollars in the late 1980s. Add to that the price of installing one of these giants, the electrical equipment needed for it, and the salary for keeping a Xerox-trained Field Engineer on staff (the operators could perform a lot of the maintenance, but a trained FE was needed nearly full time to keep the machine running in good order) and these systems were way out of the reach of most smaller service bureaus.
Let's See What This Baby Can Do: Example Applications
There were a lot of uses for the 9700. Some of the usual applications were bills, form letters, prospectuses, and limited partnership investment packages.
It is likely that the most popular use for these systems was billing. Most statements from credit cards, utility companies and banks were printed on 9700s for over a decade (and many are still printed on the newer Xerox DocuTech systems). With the 9700s, service bureaus could, for example, have a template for a billing statement housed on the machine, then merged with individual data to produce personalized statements for each customer who was being billed. Digitized graphics could be added for logos, signatures or other artwork.
More exotic applications were performed for insurance companies, investment houses and other such financial institutions. A 9700 might, for example, print an investor booklet or insurance document: the cover might be heavier, pre-printed stock, pulled from the auxiliary tray, and the document could be of variable length, according to the needs of each individual customer.
Printing dividend checks was another way to exploit the 9700s versatility and flexibility. The job would print a letter and dividend breakdown on plain paper, pulled from the main paper tray, and a payment check, printed on safety check stock from the auxiliary tray as the last page. The job could go straight from the printer to the perforator, folder and inserter and be sent to the post office immediately after printing.
The 9700 proved to be a solid design, both mechanically and electronically. It was gradually improved over the years, leading to the 9790, 4090 and 4135 laser printers, as well as the 8700 with its oddball output bins.**
The DocuTech systems, introduced in the early 1990s were far more sophisticated and offered much greater capacity for networking and better input controls. Service bureaus quickly embraced the newer technology and the 9700s have largely faded from the scene. A few companies still use the durable old workhorses however. For all their quirks, they were fast and reliable printers, and an important step in the history of printing.
*A sales representative who had worked for Xerox in the 70s told me that the guys at PARC had wanted to make the printer 360x360 dpi. The cost of the memory to store all those pixels made it prohibitive at the time, so 300dpi became a sort of industry standard.
**The 8700 and 8790 featured a sort of output basket which was essentially external, as opposed to the 9700s internal high-speed stackers. The basket arrangement was a bit dodgy and much more prone to jamming, misfeeds and ripping up your output. I once heard a rumour that the designer of the 8700 output trays lost his job soon after these machines came out.
References:
Much of the information for this article was learned from ten years of working at print service bureaus which used these printers.
Thanks to avalyn for reviewing my ASCII art
The Story of the Xerox 9700 Electronic Printing System (and many, many pieces of writing linked to from the site): http://www.digibarn.com/collections/printers/xerox-9700/