Abstract: An image forming apparatus including a mechanism for forming a visual image on a sheet of paper and a plurality of sheets supply mechanisms each including a sheet storage cassette detachably incorporated therein. A detector for detecting the attaching operation of the sheet storage cassettes in each of the sheets supply mechanisms is also provided. An automatic selecting circuit, which is responsive to the detector, automatically selects the sheets supply mechanisms for which the attaching operation has been detected by the detector. A signal is generated to disable the automatic selecting circuit. The disabling signal enables operation without a cassette attached to the sheets supply mechanism irrespective of the sheet size selected.

Abstract: A printer for printing data received from an external data processor is disclosed. Image data are developed responsive to the received data, and the developed image data are printed on printing paper. The printer comprises an indicator for indicating the operation state thereof. The indicator is driven so as to flicker when receiving data, and is driven so as to light when converting data into image data.

Abstract: An image recording system including a host control unit for generating image data and a printer apparatus for forming an image on a sheet of paper in accordance with the image data generated form the host control unit. The printer apparatus has a function of dividing the image into at least two image areas with respect to a boundary and of forming each of the image areas in different colors. The host control unit is adapted to apply to said printer apparatus a boundary signal indicative of the boundary of at least two image areas which are to be formed in different colors. The printer apparatus has a designating device for designating one of the image areas as an image to be formed, and a prohibiting device for prohibiting formation of the image area other than the image area designated.

Abstract: An image recording system including a host control unit for generating image data and a printer apparatus for forming an image on a sheet of paper in accordance with the image data. The printer apparatus has a function of dividing the image into two image areas with respect to a boundary extending in a direction orthogonal to the direction of transport of the paper and of forming each of the image areas with different colors. The host control unit is adapted to supply to the printer apparatus a boundary signal indicative of the boundary of the image areas.

Abstract: A data processing system wherein one of a number of central processing units writes a command for data transfer to it from a second processor over a data bus to a common memory and a digital code to an interrupt table, the code indicating interruption of the second processor. Decoding apparatus responsive to the digital code causes the second central processor to read the command for data transfer from the memory and transfer data to the first central processor.

Abstract: An image information output apparatus which includes a circuit for setting conditions for a "0" or a "1" level in an X direction, a circuit for setting conditions for a "0" or a "1" level in a Y direction with respect to each of respective image units over an entire output image plane divided into an X-Y matrix configuration, a circuit for generating an output timing signal for each of the image units, an AND circuit for ANDing two signals so as to output conditional signals at every generation of the output timing signal for each of the image units, one conditional signal being related to the X direction condition setting and one conditional signal related to the Y direction condition setting, a circuit for storing image information, and a circuit for outputting the stored image information, one image unit by one image unit, for each "1" level output signal of the AND circuit.

Abstract: An improved image reading apparatus which is so arranged that, by providing marks shaded to a predetermined density or darkness for setting a required reading area on an image reading surface, the start mark and end mark are detected by a solid state image sensor for supplying image signals within the required reading range into memory unit based on results of the on detection so as to reduce the memory capacity of the memory unit.