Abstract: A bit-image printer is disclosed, having a page memory, a font memory and a font library. Fonts are selected from the library for use in composing a page image in the page memory. Loading of font characters into the page memory is controlled by the position of a cursor located within page memory. The font characters include cursor parameters which control the loading of the character into page memory, based upon current cursor position, and control movement of the cursor to a new location, in preparation for loading of the next character into page memory. After a page image is composed, the image is used to control an LED printhead which images the photoconductor of a xerographic reproduction device.

Abstract: Secondary storage subsystems exchange messages and data with host data processing systems and also forward messages between host systems. Host systems thereby communicate with each other in addition to having access to data in subsystem storage. Access to subsystem storage is initiated by a "request" sent from a host to the subsystem. Each request is a message containing an array of one or more commands, each command specifying a transfer of data or a control function to be performed by the subsystem. A subsystem may process more than one request at a time. It also may process the commands in a request in an arbitrary sequence suited to the availability of subsystem resources and data links to host systems. After all commands in a request have been processed the subsystem transmits an associated "completion" message to the host system which originated the request. The completion message indicates the status of completion or abnormal termination of each command in the associated request.