LaserWriter
The LaserWriter is a laser printer with built-in PostScript interpreter sold by Apple, 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.[1][2]
Introduced
March 1, 1985
February 1, 1988
US$6,995 (equivalent to $19,820 in 2023)
12 MHz
1.5 MB
1
512 KB
760 watts
Monochrome
300
8 pages per minute
77 lb (35 kg)
(H × W × D) 11.5×18.5×16.2 in (29×47×41 cm)
Description[edit]
Hardware[edit]
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.[13] 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.[14]
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 of 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[edit]
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.[15]
Design[edit]
The LaserWriter was the first major printer designed by Apple to use the new Snow White design language created by Frog Design. 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[edit]
Apple's RIP was of its own design, and was implemented using 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 HP's LaserJets, especially the ones which offered a plug-in PostScript interpreter card, required special parity-type PS/2 RAM modules with a "presence detect" function according to IBM specs.