Abstract: An electronic apparatus comprising a printed circuit board including a circuit for inputting and outputting signals between an external apparatus through a connector which can effectively chassis-earth high frequency noise generated from a circuit of the printed circuit board due to a first conductive pattern electrically connecting the connector and the circuit of the printed circuit board, a second conductive pattern connected to a chassis-earth, and a condenser provided between one end portion of the first conductive pattern and the second conductive pattern, The width of the one end portion of the first conductive pattern between the condenser and the connector is formed to be wider than the width of the portion of the first conductive pattern between the condenser and the circuit of the printed circuit board.

Abstract: A dot-matrix printer of the invention uses a font cartridge unit storing in advance character pattern data corresponding to characters other than standard characters. The font cartridge unit comprises a ROM or RAM storing character pattern data in a storage area in units of pages. A CPU sets a given page address in a page address register in the font cartridge unit in the case of dot printing of characters other than standard characters. The CPU reads out desired character pattern data from the storage area of the ROM or RAM corresponding to the preset page address, and stores the readout data in a work memory. A printing mechanism controller controls a printing mechanism including a print head in accordance with the character pattern data stored in the work memory so as to execute dot printng of, e.g., high-density characters other than standard characters.

Abstract: A dot-matrix printer of the invention uses a font cartridge unit storing in advance character pattern data corresponding to characters other than standard characters. The font cartridge unit has a memory area divided into a plurality of page areas, and comprises memory groups consisting of ROMs and RAMs storing character pattern data in units of page areas. A CPU sets a predetermined page address in a page address register in the font cartridge unit when dot printing of characters other than standard characters is performed. The CPU reads out desired character pattern data from the page area of the memory group corresponding to the preset page address. The CPU recognizes that no ROM is mounted at a position corresponding to the page area when predetermined data cannot be read out from the ROM.

Abstract: A pulse motor control device is provided with a microprocessor for presetting time data in a counter to determine a rotating speed of a pulse motor according to an interrupt signal, in which an overflow pulse from the counter is supplied as an interrupt signal to the microprocessor and is also applied as a phase data changing signal, which determines the period of the phase data, to a motor control circuit. A gate is provided at a prestage of the interrupt terminal of the microprocessor. When the pulse motor is driven at a constant speed, the gate is disabled to prohibit the interrupt signal from being applied to the microprocessor.