Gestetner A193 Service Manual page 793

Internal Controller
• Buffers data received from the PC
• Processes the data sent from the PC and converts the video data using
the PCL or PostScript interpreter accordingly (toner saving and edge
enhancement functions affect the data when processing.)
• Emulation switching (PS/PCL) if auto switching mode is selected when the
printer enhancement unit is installed
• Auto input tray switching
Machine Interface
The function of these signals are as follows.
• Receives status data from the machine
• Receives timing signals for horizontal and vertical image synchronization
• Sends commands to the machine (e.g. tray selection, front panel display in
printer mode)
• Sends the video data.
Note that the video data is sent through the BICU, and directly drives the
laser diode. That is, all of the data processing is performed by the
controller, and the BICU's processing functions are not used.
(A643) 1-4 SM