after all three motions complete. This minimized the time spent waiting for the motions to complete. A related model, the Diablo 1620, includes a keyboard and strongly resembles a slightly overgrown Selectric typewriter. In fact, a "local/remote" switch permits it to be used as an offline typewriter as well as an interactive computer terminal. Unfortunately for a typist (in either role), the daisy wheel mechanism hides the area just printed. Firmware in the machine makes the carriage move quickly to the right of the typing position, revealing the most recently typed characters, after a few moments of inactivity. The result was still unsatisfactory to many users. Only a very slow typing speed would allow the wheel to get out of the way after every character; faster typing speeds resulted in the wheel continuously hiding the typed copy until the typist paused. This made checking the copy for errors a bit more awkward and slow than on actual typewriters or on Selectric-based terminals. The same mechanism was used in Xerox's 850 display typing system and 860PDS word processor, and 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 RS-232 serial interface), supported by Digital's WPS-8 word processing software. The printer became so common, with so much software supporting its command language, that Diablo emulation became an expected feature on other daisy-wheel printers and even on early laser printers. This was so pervasive that at least one company lived by testing printers for full Diablo 630 compatibility. References Further reading External links Diablo Model 630/630 ECS Printers/Terminals API Interface Complete description of printers and command language, with all modes Brief description of Diablo 630 command language Diablo 630 to PostScript Translator Daisy wheel printers