| 摘要 |
1487121 Shift registers INTERNATIONAL BUSINESS MACHINES CORP 1 May 1975 [14 May 1974] 18157/75 Heading G4C To edit a text, a shift register storing a line of data bits representing text has a normal path 34 (Fig. 2A) and a by-pass path 36 so that the order of the bits may be changed, gaps in the data may be closed and data bits may be deleted. The shift register may be either a medium capable of supporting magnetic bubble domains in which case drive pulses for the register in the form of an unchanged repetitive sequence of drive pulses are provided by a rotating magnetic field or a charge coupled device in which case three phase propagation lines receive successive signals. As described the normal path includes a freeze and input/output position at which new data may be written by a write circuit (48, Fig. 2B, not shown), annihilated (in the case of the bubble domain embodiment by passing a large current through freeze loop (46)) or held whilst other data is shifted round the by-pass loop. The editing shift register (24, Fig. 1, not shown) is connected between the read decoder output from and the write decoder input to a plurality of shift registers (SR1-SRn) used for storing data text. A spare shift register (SR) is provided so that the contents of the shift registers may be interchanged. |
