Patent GB-1487122-A (GB)
Title: Data manipulation apparatus
IPC: G11C11/14
Filed: 1975-05-01
Abstract: 1487122 Magnetic storage arrangements INTERNATIONAL BUSINESS MACHINES CORP 1 May 1975 [14 May 1974] 18180/75 Heading H3B [Also in Division G4] Data manipulation apparatus comprises a plurality of dynamic shift registers in which the data can be stored, switch means for controllably connecting the shift registers in series for sequential access of data in the shift registers, and switch means for controllably disconnecting the shift registers from one another and for making the shift registers closed loop shift registers. The editing system of Fig. 1 has passive storage 22 consisting of a number of page shift registers (including one or more spares), with switches to connect them in series or to form respective closed loops or to be addressed directly by a read decoder RD. Active storage 24 has a number of line shift registers (including one or more spares) and an edit shift register, with switches to connect them in series (for data movement selectively up or down with the same direction within each register in both cases) or to form respective closed loops. Data can be passed from the passive storage 22 to the active storage 24 using sequential access or random access of the passive storage. For sequential access, the registers of the passive storage 22 are connected in series, transfer being via line 31 (top), and data can be returned via line 26 to the bottom register of the passive storage 22 (switch S7 being in the other position to that shown). In random access, read decoder RD selects a register of the passive storage 22 to feed the active storage 24 from which data can be returned to any register of the passive storage 22 via a write decoder WD (also used for entry from data entry means 32 comprising a keyboard and BCD encoder). The edit shift register may accommodate more than one line. The edit shift register has a freeze and input/output bit position with a bypass round it to permit insertion, deletion, changes of position and closing/ creating gaps. The registers of the active storage 24 may be divided into two groups, "background" and "foreground", separately controlled, so that a line can be deleted by connecting both groups in series and moving the data in the appropriate direction until the line is at the boundary between the groups, within the "background", whereupon the "background" continues to move while the registers of the "foreground" recirculate. Similarly, a line can be inserted into the "foreground" at the boundary while the "background" registers recirculate. Two pages in the passive storage 22 can be interchanged using the write and read decoders WD, RD and buffering in the spare page shift register. Two lines in the active storage 24 could be interchanged similarly if read decoder RD were modified to also act as a write decoder for the active storage 24 and a read decoder for the latter were also provided. Keyboard operations mentioned are character entry, backspace, carriage return, tab set, tab release, margin set, margin release, page skip, page selection, page insertion, line advance, line backspace, line deletion, line insertion, character deletion, character insertion. Pointers, being recirculating shift registers containing one or more "1" bits defining positions to be controlled, are provided for pages, lines, characters, &c. Several pointers may be combined to share a common loop, e.g. those for left and right line margins and tab. Use of format codes to determine paragraphs, sentences, words, margin justification and centring is mentioned. Constructions.-The system can be implemented using magnetic bubble domain technology or charge-coupled devices. In the former case, constructions are given for the shift registers including use of permalloy T, I and Y bars and current loops for controlling the switching and controlling by-pass of a bit and freeze of a bit and freeze of a whole (pointer) register. The magnetic bubble-propagation field always rotates in the same direction. For example, Fig. 8c shows two of the line shift registers, adjacent to each other in the "background" and "foreground" respectively (see above), including a bubble domain generator 94, a magnetoresistive bubble domain sensor 86, an annihilator 88 and (shaded) control conductors (current loops) for read 82, write 98 and switches S3-S6. In other parts, a plurality of switches controlled in common have a common current loop. The BCD encoder has a bubble generator for each binary output, feeding a respective annihilator, each input to be encoded switching the outputs of a respective combination of the generators away from the annihilators to the respective binary outputs, the encoder using I and T bars, and current loops for controlling the switching.