Abstract: A virtual transmission system comprises a first and second virtual serial ports; a first transmission/reception buffer region set with the first virtual serial port as a write port and the second virtual serial port as a read out port; a second transmission/reception buffer region set with the first virtual serial port as a read out port and the second virtual serial port as a write port; and a control portion for writing data outputted from the first virtual serial port into the first transmission/reception buffer region, for outputting data written in the first transmission/reception buffer region to the second virtual serial port, for writing data outputted from the second virtual serial port into the second transmission/reception buffer region, and for outputting data written in the second virtual serial port to the first transmission/reception buffer region.

Abstract: A method and a device for transmitting print data from a computer to a print control device for controlling a printer, wherein a desired one of attribute data sets which accompany respective image data sets is replaceable by a new image data set in a data transmission mode of the computer, and the attribute data set accompanying the original image data set replaced by the new image data set is suitably changed according to the new image data set. The print data including the new image data set and the changed attribute data set are transmitted to the print control device. The print data may include direct image data such as bit map data, and non-direct image data which include indirect image data such as character data and graphic data, and print control data such as attribute data.

Abstract: A method and a device for transmitting print data from a computer to a print control device for controlling a printer, wherein a desired one of attribute data sets which accompany respective image data sets is replaceable by a new image data set in a data transmission mode of the computer, and the attribute data set accompanying the original image data set replaced by the new image data set is suitably changed according to the new image data set. The print data including the new image data set and the changed attribute data set are transmitted to the print control device. The print data may include direct image data such as bit map data, and non-direct image data which include indirect image data such as character data and graphic data, and print control data such as attribute data.

Abstract: A method and a device for transmitting print data from a computer to a print control device for controlling a printer, wherein a desired one of attribute data sets which accompany respective image data sets is replaceable by a new image data set in a data transmission mode of the computer, and the attribute data set accompanying the original image data set replaced by the new image data set is suitably changed according to the new image data set. The print data including the new image data set and the changed attribute data set are transmitted to the print control device. The print data may include direct image data such as bit map data, and non-direct image data which include indirect image data such as character data and graphic data, and print control data such as attribute data.