Patent GB-1296176-A (GB)
IPC: G06F40/189
Filed: 1971-04-19
Abstract: 1296176 Cathode-ray tube displays INTERNATIONAL BUSINESS MACHINES CORP 19 April 1971 [2 March 1970] 21759/71 Heading H4T The Specification describes a cathode-ray tube display arrangement for composing, editing and formatting character data included in a text and claims means for justifying the text including means for calculating the deficit between the length of each displayed line of text and the distance between specified margins the means then operating to insert spaces in each line to nullify the deficit together with selectively operable means for deleting the spaces to return the displayed lines to their original lengths. In the general operation of the arrangement Alpha- Numeric character data derived from a magnetic card reader-recorder 15 or from selected keys 19, of a keyboard 12 is entered into a bulk text storage unit in a processor 17 where it is processed in accordance with its information content and in accordance with commands from function keys (on keyboard 12) and displayed on a cathode-ray tube display device 11. The scale 30, which is displayed only when specified by the operator to assist in setting up the various margins and formats to be utilized, precedes the display of the first line of characters and in accordance with the setting of a control 959 the scale may represent standard spacing with a selectable, 10 or 12 pitch (i.e. 10 to 12 characters per inch when printed on a 10 or 12 pitch printer) or proportional spacing PS may be selected in which case the displayed scale shows that 72 space units would result in an inch of printed material. When standard spacing is specified each character has a width of nine space units and in proportional spacing each character is assigned a weighted space value between four and nine space units in accordance with character size. When the scale is displayed the left and right hand margins 36 and 38 respectively are established by positioning a cursor 34 at these positions under control of a cursor motion section 33 of keyboard 12. The margins, for particular lines of characters, such as the left-hand margin 21, are set up in similar manner and data specifying such margins (sixteen different sets may be set up) is stored in processor 17. The latter determines which lines (e.g. of a page) are displayed and controls the display of line numbers 26 (a maximum of 16 lines is displayed at a time) and of paragraph marks 28. Additions and deletions of text material may be effected by keyboard keys 19 at the location of a cursor 32 the position of which is controlled by keyboard section 33 and whether or not such alterations are effected the number of words which are displayed between the pre-set margins on each line is optimized automatically by processor 17 which causes a word or words to be shifted from overfilled lines to underfilled lines so that each line other than the last line of a paragraph contains as many words as can be entered between the margins. When the text has been corrected operation of button J causes processor 17 to justify either the line addressed by the cursor 32 or the whole of the paragraph containing such line (determined by the appropriate key, in section 33) by the insertion of interletter spacing distributed between the words such that the last non-space character is located adjacent to the right hand margin. If, after the text has been justified, further text changes are required the display is dejustified by operation of the dejustify button DJ, the text is then altered, word optimized and finally rejustified. The data in processor 17 is then transferred to the magnetic card readerrecorder 15 which produces a record of the edited &c. text for controlling a printer. The complete operation is described with reference to block circuit and flow diagrams.