Apple ImageWriter (1983)

What the Apple ImageWriter was

The Apple ImageWriter was a nine-pin serial impact dot-matrix printer that Apple Computer introduced in 1983. It carried the model number A9M0303 and was the standard printer Apple offered across its personal-computer range, from the Apple II family to the original Macintosh. After the ImageWriter II arrived in 1985, the original model became known retrospectively as the ImageWriter I.

A rebadged C. Itoh 8510

Rather than design a print mechanism from scratch, Apple based the ImageWriter on an existing dot-matrix engine. Both Wikipedia and the Centre for Computing History document it as a re-packaged C. Itoh Electronics 8510 printer fitted with a modified ROM and pinout, so that it communicated with Apple's computers and matched Apple's own industrial design. Branding a mechanism built by a specialist manufacturer was a common practice in the early-1980s printer market.

How it printed: nine-pin impact dot matrix

Like other machines described in the general account of dot-matrix printing, the ImageWriter formed characters and images by driving a vertical column of nine small pins against an inked ribbon, stamping patterns of dots onto the paper as the print head swept across the page. In text mode the printer was logic-seeking and printed bidirectionally, advancing the head in whichever direction was shorter, while graphics and near-letter-quality passes printed in a single direction for tighter registration. Documented output reached roughly 120 characters per second.

Bitmap graphics for the Macintosh

The name ImageWriter reflected the machine's ability to print dot-addressable bitmap graphics at up to 144 dots per inch, not just fixed character shapes. Wikipedia describes it as the graphical printer that allowed the original Macintosh to reproduce on paper the bitmapped image it drew on screen — an early form of what-you-see-is-what-you-get (WYSIWYG) printing. Because the Mac's on-screen graphics and the ImageWriter both worked in dots rather than typewriter characters, the printed page could correspond closely to the display, which helped popularise the idea of composing documents visually.

Compatibility across the Apple line

Although the ImageWriter was introduced primarily for the Apple II, sources record that it worked across Apple's entire computer product line, including the Macintosh 128K. It connected over a serial interface — the connection type Apple standardised on for its peripherals of the period — in contrast to the parallel connection used by the earlier Apple Dot Matrix Printer that it replaced.

Documented specifications

Authoritative records agree on the machine's core specifications: a nine-pin impact dot-matrix mechanism derived from the C. Itoh 8510, up to 144 dpi resolution, printing at about 120 characters per second over a serial interface, under the model number A9M0303. Figures that cannot be traced to an authoritative source are omitted here rather than estimated.

Place in Apple's printer history

The ImageWriter replaced Apple's earlier parallel-interface Apple Dot Matrix Printer and, in September 1985, was itself succeeded by the ImageWriter II, which added colour printing with a four-colour ribbon and faster draft speeds. A later ImageWriter LQ, introduced in 1987, moved to a 27-pin head for letter-quality output. For contrast with the laser technology that reshaped desktop output in the same era, see the original HP LaserJet.