The LaserWriter is a laser printer with built-in PostScript interpreter sold by Apple Computer, Inc. from 1985 to 1988. It was one of the first laser printers available to the mass market. In combination with WYSIWYG publishing software like PageMaker, that operated on top of the graphical user interface of Macintosh computers, the LaserWriter was a key component at the beginning of the desktop publishing revolution.
Video LaserWriter
History
Development of laser printing
Laser printing traces its history to efforts by Gary Starkweather at Xerox in 1969, which resulted in a commercial system called the Xerox 9700. IBM followed this with the IBM 3800 system in 1976. Both machines were large, room-filling devices handling the combined output of many users. During the mid-1970s, Canon started working on similar machines, and partnered with Hewlett-Packard to produce 1980's HP 2680, which filled only part of a room. Other copier companies also started development of similar systems.
HP introduced their first desktop model with a Ricoh engine for $12,800 in 1983. Sales of the non-networked product were unsurprisingly poor. In 1983 Canon introduced the LBP-CX, a desktop laser printer engine using a laser diode and featuring an output resolution of 300 dpi. In 1984, HP released the first commercially available system based on the LBP-CX, the HP LaserJet.
Apple's development
Steve Jobs of Apple Computer had seen the LPB-CX while negotiating for supplies of 3.5" floppy disk drives for the upcoming Apple Macintosh computer. Meanwhile, John Warnock had left Xerox to found Adobe Systems in order to commercialize PostScript and AppleTalk in a laser printer they intended to market. Jobs was aware of Warnock's efforts, and on his return to California he started working on convincing Warnock to allow Apple to license PostScript for a new printer that Apple would sell. Negotiations between Apple and Adobe over the use of Postscript began in 1983 and an agreement was reached in December 1983, one month before Macintosh was announced. Jobs eventually arranged for Apple to buy $2.5 million in Adobe stock.
At about the same time, Jonathan Seybold (John W. Seybold's son) introduced Paul Brainerd to Apple, where he learned of Apple's laser printer efforts and saw the potential for a new program using the Mac's GUI to produce PostScript output for the new printer. Arranging his own funding through a venture capital firm, Brainerd formed Aldus and began development of what would become PageMaker. The VC coined the term "desktop publishing" during this time.
Release
The LaserWriter was announced at Apple's annual shareholder meeting on January 23, 1985, the same day Aldus announced PageMaker. Shipments began in March 1985 at the retail price of US$6,995, significantly more than the HP model. However, the LaserWriter featured AppleTalk support that allowed the printer to be shared among as many as sixteen Macs, meaning that its per-user price could fall to under $450, far less expensive than HP's less-advanced model.
The combination of the LaserWriter, PostScript, PageMaker and the Mac's GUI and built-in AppleTalk networking would ultimately transform the landscape of computer desktop publishing. At the time, Apple planned to release a suite of AppleTalk products as part of the Macintosh Office, with the LaserWriter being only the first component.
While competing printers and their associated control languages offered some of the capabilities of PostScript, they were limited in their ability to reproduce free-form layouts (as a desktop publishing application might produce), use outline fonts, or offer the level of detail and control over the page layout. HP's own LaserJet was driven by a simple page description language, known as Printer Command Language, or PCL. The version for the LaserJet, PCL4, was adapted from earlier inkjet printers with the addition of downloadable bitmapped fonts. It lacked the power and flexibility of PostScript until several upgrades provided some level of parity. It was some time before similar products became available on other platforms, by which time the Mac had ridden the desktop publishing market to success.
Maps LaserWriter
Description
Hardware
The LaserWriter used the same Canon CX printing engine as the HP LaserJet, and as a consequence early LaserWriters and LaserJets shared the same toner cartridges and paper trays. PostScript is a complete programming language that has to be run in a suitable interpreter and then sent to a software rasterizer program, all inside the printer. To support this, the LaserWriter featured a Motorola 68000 CPU running at 12 MHz, 512 kB of workspace RAM, and a 1 MB frame buffer.
At introduction, the LaserWriter had the most processing power in Apple's product line--more than the 8 MHz Macintosh. As a result, the LaserWriter was also one of Apple's most expensive offerings. For implementation purposes, the LaserWriter employed a small number of medium-scale-integration Monolithic Memories PALs, and no custom LSI, whereas the LaserJet employed a large number small-scale-integration Texas Instruments 74-Series gates, and one custom LSI. The LaserWriter was, thereby, in the same form factor (for its RIP), able to provide much greater function, and, indeed, much greater performance, all within the very same LBP-CX form factor, although the external packaging was, for marketing purposes, somewhat different.
Networking
Since the cost of a LaserWriter was several times that of a dot-matrix impact printer, some means to share the printer with several Macs was desired. LANs were complex and expensive, so Apple developed its own networking scheme, LocalTalk. Based on the AppleTalk protocol stack, LocalTalk connected the LaserWriter to the Mac over an RS-422 serial port. At 230.4 kbit/s LocalTalk was slower than the Centronics PC parallel interface, but allowed several computers to share a single LaserWriter. PostScript enabled the LaserWriter to print complex pages containing high-resolution bitmap graphics, outline fonts, and vector illustrations. The LaserWriter could print more complex layouts than the HP Laserjet and other non-Postscript printers. Paired with the program Aldus PageMaker, the LaserWriter gave the layout editor an exact replica of the printed page. The LaserWriter offered a generally faithful proofing tool for preparing documents for quantity publication, and could print smaller quantities directly. The Mac platform quickly gained the favor of the emerging desktop-publishing industry, a market in which the Mac is still important.
Design
The LaserWriter was the first major printer designed by Apple to use the new Snow White design language created by Frogdesign. It also continued a departure from the beige color that characterized the Apple and Macintosh products to that time by using the same brighter, creamy off-white color first introduced with the Apple IIc and Apple Scribe Printer 8 months earlier. In that regard it and its successors stood out among all of Apple's Macintosh product offerings until 1987, when Apple adopted a unifying warm gray color they called Platinum across its entire product line, which was to last for over a decade.
The LaserWriter was also the first peripheral to use the LocalTalk connector and Apple's unified round AppleTalk Connector Family, which allowed any variety of mechanical networking systems to be plugged into the ports on the computers or printers. A common solution was the 3rd party PhoneNet which used conventional telephone cables for networking.
Legacy
Apple's RIP was of its own design, and was implemented using remarkably few ICs, including PALs for most combinatorial logic, with the subsystem timing, DRAM refreshing, and rasterization functions being implemented in very few medium-scale-integration PALs. Apple's competitors (i.e., QMS, NEC, and others) generally used a variation of one of Adobe's RIPs with their large quantity of small-scale-integration (i.e., Texas Instruments' 7400 series) ICs.
In the same time-frame as Apple's LaserWriter, Adobe was licensing the very same version of PostScript to Apple's potential competitors (Apple's PostScript licensing terms were non-exclusive); however, all non-Apple licensees of PostScript generally employed one of Adobe's PostScript "reference models" (Atlas, Redstone, etc.) and even Linotype's first image setter which featured PostScript employed such a "reference model" (but with customization for the Linotronic's different video interface, plus the necessary implementation of "banding" and a hard drive frame buffer and font storage mechanism). Indeed, the PostScript language itself was concurrently enhanced and extended to support these high-resolution "banding" devices (as contrasted to the lower resolution "framing" devices, such as the LaserWriter, in which the entire "frame" could be contained within the available RAM).
In most cases, such RAM was fixed in size and was soldered to the logic board. In late PostScript Level 1, and in early PostScript Level 2, the RAM size was made variable and was generally extensible, through plug-in DIMMs, beyond the 2.0 to 2.5 MB minimum (0.5 to 1.0 MB for instructions, depending upon PostScript version, and 1.5 MB minimum for the "frame buffer", for the lowest resolution devices, 300 dpi), as more than 300 dpi of course required more RAM, and some LaserWriters were able to change between 300 dpi and 600 dpi, depending upon how much RAM was installed. 600 dpi, for example, required 6 MB of RAM, but 8 MB of RAM was more commonly found.
At this point, Apple's LaserWriters were employing generic non-parity RAM, whereas H-P's LaserJets, especially the ones which offered a plug-in PostScript interpreter card, required special parity-type RAM with a special "presence detect" function.
Other LaserWriter models
Building on the success of the original LaserWriter, Apple developed many further models. Later LaserWriters offered faster printing, higher resolutions, Ethernet connectivity, and eventually color output in the Color LaserWriter. To compete, many other laser printer manufacturers licensed Adobe PostScript for inclusion into their own models. Eventually the standardization on Ethernet for connectivity and the ubiquity of PostScript undermined the unique position of Apple's printers: Macintosh computers functioned equally well with any Postscript printer. After the LaserWriter 8500, Apple discontinued the LaserWriter product line in 1997 when Steve Jobs returned to Apple.
LaserWriter II
In 1988, to address the need for both an affordable printer and a professional printer, the LaserWriter II was designed to allow for complete replacement of the computer circuit board that operates the printer. Across all the different models, the print engine was the same.
- For low-end users, there was the LaserWriter II SC, a host-based QuickDraw printer connected via SCSI that did not use PostScript and did not require a license from Adobe. It had two SCSI ports to allow daisy-chaining of the printer with other SCSI devices such as hard drives. It did not support AppleTalk.
- For midrange users, the LaserWriter II NT provided PostScript support and AppleTalk networking.
- For high-end users, the LaserWriter II NTX also included a SCSI controller for storage of printer fonts on a hard drive dedicated for use by the printer.
Three years later in 1991, two updated versions of the LaserWriter II were produced.
- The LaserWriter IIf had a faster processor than the IINTX, a newer version of PostScript and also HP PCL, and included the SCSI interface for font storage on an external hard drive
- The LaserWriter IIg had the capabilities of the IIf, and was also the first LaserWriter with a built-in Ethernet network interface.
By this time, most of the combinatorial logic which was formerly performed by PALs had been incorporated into a new LSI chip for greater flexibility, increased reliability and lower cost. This LSI, or a version of it, found its way into subsequent LaserWriters, and possibly even some competitive products, the first of which competitors may have been Hewlett-Packard's ISA board which behaved as a parallel-attached PostScript interpreter, and which was connected outboard to a CX-based marking engine, such as a LaserJet, or, through an adapter board, to an SX-based marking engine, such as a LaserJet II. The emergence of ISA boards which supported LocalTalk made LaserWriters immediately connectable to PCs, and most probably undermined the success of H-P's inboard PostScript interpreter.
Beyond LaserWriter II
The aforementioned LaserWriter models were fixed at 300 dpi resolution.
With the availability of the 600 dpi-capable "marking engine" from Canon, LaserWriters were available in 300 dpi/600 dpi models, with the actual resolution being dependent upon how much RAM was installed, and all RAM was in user-installable DIMMs. On some models the frame-cache/font-cache could be buffered on a user-installable internal (2.5" SCSI) or external (3.5" or 5.25" SCSI) hard drive, although Apple itself did not provide the internal 2.5" SCSI drive option (except on the very rare Japanese-language version of the LaserWriter Pro 630; the Japanese-language version still retained the option for an external 3.5" or 5.25" SCSI drive).
References
External links
Source of article : Wikipedia
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