GB/T 17540-1998

GB/T 2787-1981 Keyboard for international information processing interchange using the 7-bit coded character set--Alpha-numeric area GB/T 4872-1985 Office machines and data processing equipment--Principles governing the positioning of control keys on key-boards GB/T 7188-1987 Office machines and data processing equipment--Keyboard layouts for numeric applications GB/T 7513-1987 Layout of the Chinese ideographs on keyboard GB/T 9312-1988 General specification of line printer GB/T 9311-1988 Adding machines and calculating machines--Keytop and printed or displayed symbols GB/T 9310-1988 Adding machines and calculating machines--Numeric section of ten-key keyboards GB/T 9309-1988 Office machines and data processing equipment--Functionkey symbols on typewriters