GB1169949A - Information Display - Google Patents

Abstract

1,169,949. Computer control of display means. WESTERN ELECTRIC CO. Inc. 25 Nov., 1966 [29 Nov., 1965], No. 52779/66. Heading G4A. [Also in Division H4] An information display system comprises means for generating a display pattern, means for storing signals associated with distinctive entities of the pattern, means for applying a first portion of the stored signals of each entity to control the generating means and produce a visual representation of the pattern, and means responsive to the visual representation of one of said entities for transferring display control to a second portion, distinctive from the first, of the stored signals of that entity. A pattern is traced out on the screen of an oscilloscope display unit 130 under control of instruction words stored in a display memory network 110. The pattern shown in Fig. 1 has three entities, viz. representations of a resistor and capacitor and the word " MOVE." The memory network 110 has for each entity a set of display words followed by a set of control words. Normally, the pattern is traced out repeatedly by reading out, for each entity in turn, first the display words (in turn) and then the first control word which causes a jump to the first display word for the next entity. The first control word for the last entity causes a jump to the first display word for the first entity, to repeat the cycle. Each word has an operand portion and an operation portion. In the case of display words, the operation portions control any necessary beam blanking and control how the display unit 130 will respond to the respective operand portions, e.g. treat them as absolute values or increments in beam position co-ordinates, identifications of characters to be displayed, scale and reflection factors, beam intensity, and/or commands to enable or disable the light probe 131 (see below). When the operator wishes to, say, move the resistor displayed to the dotted position shown in Fig. 1, he places the light probe 131 on the displayed word " MOVE." When the probe is reached during the next regeneration of the pattern, it responds to the light from the screen to cause a control computer 150 (e.g. by interrupting it) to set a mask register. When the first control word in the memory network 110 associated with the " MOVE " entity is reached, the operation portion of it enables a comparator 160 to detect that a flag portion of the operand portion of the word matches the mask register, thereby causing the control computer 150 to increase by one the current address reached in the memory network 110, viz. the address of the first control word. The control computer examines the word at this increased address, viz. the second control word for the " MOVE " entity, and since this word is in fact non-zero, it causes a jump to a " move " routine in the control computer 150, as soon as the light probe 131 has been removed. The operator now places the light probe 131 on the displayed entity he wants moved (the resistor). The system obtains the address of the first control word associated with the entity to be moved, by comparison as before, and increases its address by two to obtain the third control word which indicates the address of the first display word associated with the entity to be moved. Provided the light probe 131 has been removed again, the display memory network 110 now cycles. The light probe 131 is placed at the position the entity is to be moved to and when the beam reaches it the beam co-ordinates are automatically inserted into the appropriate display words for the entity to be moved, so that subsequently during cycling of the display memory network 110, the entity will be traced out in the new position. A central computer 200 initially loads the display memory network 110 and the control computer 150 via a buffer register 180. Communication in the other direction is also possible, following interrupt of the central computer 200. The memory network 110 could be part of the memory of the control computer 150. The light probe 131 contains a filter so that it responds only to the initial energization of the phosphor, i.e. not to the afterglow.