Patent GB-890182-A (GB)
Title: Improvements in or relating to binary information storage and transfer systems
IPC: G11C19/06
Filed: 1958-11-19
Abstract: 890,182. Circuits employing bi-stable magnetic elements. BURROUGHS CORPORATION. Nov. 19, 1958 [Nov. 25, 1957], No. 37172/58. Class 40 (9). [Also in Group XIX] A shift register comprises bi-stable magnetic cores with clearing windings linked with the whole cross-section of each core and transfer windings linked with part only of the crosssection. Each core 10 has a central aperture and at least two smaller apertures A, B, Fig. 5A, dividing the core into limbs l1 to l4. A core is " cleared " by a central conductor 12 so that the flux flows in the same direction around thearm in all the limbs as shown. This condition represents the binary digit " 0." The aperture B is " blocked " since a pulse in either direction in conductor 18 tends to drive one of the limbs 13, l4 further into saturation and cannot change the flux. The flux in limb l3 can be reversed by a pulse in winding 14, Fig. 5B, or 16, Fig. 5C. The core is then " set " and represents the digit " 1." A pulse of small amplitude in winding 16 may reverse the local flux around aperture A without disturbing the set condition of the core, Fig. 5D. Transfer of information.-A stored digit is transferred from core 20, Fig. 6A, to core 22, Fig. 6B, by means of transfer windings 32, 34 connected in parallel to leads p. Six turns of winding 32 are linked with aperture B, core 20 and five turns of winding 34 are linked with aperture A, core 22. This unsymmetrical arrangement determines the direction of transfer. The receiving core 22 is always cleared by winding 26 before a transfer. If cores 20, 22 are both cleared, a transfer pulse divides equally between the windings 32, 34 and is insufficient to change the flux around the blocked apertures B, A. If core 20 is set to " 1," as shown in Fig. 6A, a transfer pulse switches the flux around aperture B, core 20 (see Fig. 6B) and the back E.M.F. aids the pulse in winding 34 to set core 22 to " 1.'' Core 20 is then cleared by winding 24, Fig. 6C, the local flux around aperture A, core 22, being reversed without alteration of the core setting. One-dimensional shift register, Fig. 8.-The cores are arranged in two sets consisting of ODD cores 101, 103, 105 and EVEN cores 102, 104, 106. When all the cores are clear, information is inserted in the EVEN cores using windings 48, 50, 52. A pulse source 74, a delay line 76 and a driver 78 are used to produce a cycle of four pulses on leads 62, 38, 72, 46. A pulse on lead 62 and transfer loops 54, 56, 60 transfers the information in a forward direction from the EVEN cores to the ODD cores, a pulse on lead 38 clears the even cores, a pulse on lead 72 transfers the information in a forward direction from the ODD cores to the EVEN cores again, using transfer windings 64, 66, 68 and a pulse on lead 46 clears the ODD cores. The information is thus stepped along the EVEN cores, one step for every pulse from source 74. The last ODD core 105 may be linked by transfer loop 68, 70 to the first EVEN core 102 to form a ring in which this information can be circulated by pulses. Bi-directional shift register, Fig. 9.-Each core is formed with a central aperture and four smaller apertures. The ODD and EVEN cores are linked by two sets of transfer loops, one for stepping the information to the left and one for stepping it to the right. A switch with contacts 90, 92 determines which set of transfer loops is driven by the pulse source 74, delay line 76 and driver 78. Two-dimensional shift register, Fig. 10.-Cores may be arranged in a two-dimensional array, Fig. 10. Informaton may be shifted from left to right in each horizontal row by pulses from source 74 and may be shifted from top to bottom in each vertical row by pulses from source 74<SP>1</SP>. Alternatively, the same source may be switched to step information in either direction. The arrangement of Fig. 9 may be applied to a multidimensional array to achieve bi-directional shifting therein.