GB1239528A - - Google Patents

Abstract

1,239,528. Selective signalling; recording systems for business machines. DIGITRONICS CORP. 29 July, 1969, No. 38089/69. Headings G4B and G4H. A record of the operation of a business, e.g. adding, machine having character keys 24-42, Fig. 2, operable to set memory elements 58 arranged in columns on a carriage 46 which is advanced by one column position by operation of any key 24-42, comprises character key switches 114, Fig. 6, connected between a signal recording system and means 96 for generating a pulse on each column movement of the carriage. Signals representing the operated function keys are also recorded. The pulse producing means 96 may comprise a block 134, Fig. 2, associated with a column position indicator 20 and carrying a series of spaced contacts and a continuous contact which are bridged when the carriage has advanced to an intermediate position between adjacent column positions, this intermediate position being reached when the machine is mechanically committed to the entry of a character. In this manner erroneous recording of a character as a result of a dithering keystroke is avoided. The means 96 may alternatively comprise a photo-electric arrangement. When switch means 96 has been closed, the stable state output of one-shot 90 is supplied over contacts 94b, 98b and OR gate 104 to a pulse shaper 88 which introduces a delay to allow for contact bounce before triggering one-shot 90 to produce a negative-going pulse for supply to an encoder via the operated keyswitch 114 and leads 118. The arrangement 156-162 provides a signal on lead 158 for the entry of a digit 9, the corresponding key not having a key switch 114. Operation of a function key causes a mechanism to scan the data stored in memory elements 58, a cam switch 99 being closed when the machine is mechanically committed to per form the selected function. Relay 94 operates to transfer contact 94a to 94c, thereby causing pulse shaper 88 to trigger one-shot 90 to supply a signal to the recorder over lines 212 via the operated function key switch 210. Operation of a " non-add " function key causes the data stored in elements 58 to be printed out without entry into the machine memory, and as, like the digit 9 key, no key switch is provided for this function key, the arrangement 214-220 produces a corresponding signal on lead 214. Special signals may be recorded on operation of two auxiliary keys which operate contact pairs 98a, 98c and 98b, 98d to produce a negative going pulse on lead 224 or 226.