Diablo 630

The Diablo 630 was a daisy wheel printer (computer printer) sold by the Diablo Data Systems division of the Xerox Corporation. The printer was capable of letter-quality printing; that is, its print quality was equivalent to the quality of an IBM Selectric typewriter. The printer was capable of this quality at a nominal speed of 30 characters per second (roughly twice the speed of the Selectric).

Several technologies enabled this quality and speed:

• The lightweight plastic daisy wheel was rotated by a closed-loop servo and could be positioned rapidly and accurately. Because the wheel could turn in either direction, the next character was never more than 180° away from the previous character (and related characters were grouped together so the average "seek" was much less than 180°).
• The printer used cartridge-loaded ribbons; both an economical endless cloth ribbon and a high-quality single-use film ribbon were available with colored ribbons provided by third parties.
• The carriage was also servo-controlled and the printer could print with the carriage moving either forwards or backwards, saving most of the time that would otherwise be spent executing carriage-returns.
• Paper motion was similarly servo-controlled allowing quick printing of subscripts and superscripts as well as fast slewing past white space.

In addition, the daisy wheel could be easily changed, allowing a wide variety of fonts and character pitches.

The same mechanism was also sold to OEMs. One notable user was Digital Equipment Corporation who resold the printer as the LQP01 (with a parallel interface) and the LQPSE (with an RS232 serial interface) and supported by Digital's WPS-8 word processing software.