By using control codes it was possible to change the printed text style using font patterns stored in permanent ROM in the printer. The first LaserJet was a high-speed replacement for text-only daisy wheel impact printers and the noisy dot matrix printers. It was quiet compared to other contemporary printers, hence people could use the telephone while sitting near the HP LaserJet.

It was ideal for printing memos, letters, and spreadsheets. The HP LaserJet printer had high print quality, could print horizontally or vertically and produce graphics. Due to the high cost of memory, the first LaserJet only had 128 kilobytes of memory, and a portion of that was reserved for use by the controller.

It used an 8 MHz Motorola 68000 processor and could print in a variety of character fonts. It was a 300- dpi, 8 ppm printer that sold for $3,495 with the price reduced to $2,995 in September 1985. HP introduced the first laser printer for IBM PC compatible personal computers in May 1984 at the Computer Dealers' Exhibition ( COMDEX). PostScript Cartridge for LaserJet IIP, IID, III, IIID, etc. The sharing of an identical Canon engine in two competing products continued with the HP LaserJet II/III and the Apple LaserWriter II, which both used the Canon LBP-SX print engine. The use of a less-ambitious and simpler Page description language allowed HP to deliver its LaserJet to the market about a year before Apple's CX based product, and for $1000 less. HP chose to use their in-house developed Printer Command Language (PCL) as opposed to Apple, which adopted the PostScript language, as developed by Adobe Systems. The first HP LaserJet and the first Apple LaserWriter used the same print engine, the Canon CX engine. In spring of 1989 The New York Times said that HP 'dominates' the PC laser printer market. Due to a very tight turnaround schedule on the first HP LaserJet, HP elected to use the controller already developed by Canon for the CX engine in the first HP LaserJet. Most HP LaserJet printers employ xerographic laser-marking engines sourced from the Japanese company Canon.

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