The "atprint" uses the Printer Access Protocol (PAP) to send data to the LaserWriter Pro 810. There is a new version of the "atprint" that fixes a problem in PAP that prevented A/UX from making a connection to the LaserWriter Pro 810 with A/UX 3.0.[12] or 3.1.
To locate Apple software updates, search the Tech Info Library for the article "Where To Find Apple Software Updates".