GB1265014A - - Google Patents

Abstract

1,265,014. Data storage. INTERNATIONAL BUSINESS MACHINES CORP. 22 Oct., 1969, No. 51786/69. Heading G4C. A digital data storage system comprises duplexed storage arrays 1A, 1B, a configuration shift register 15, and control means arranged selectively to render either or both storage arrays active or inactive in accordance with the contents of the configuration register. Fig. 1 shows two pairs of associative storage arrays 1A, 1B, and 2A, 2B, each pair as in Specification 1,265,013 which is referred to. Each array has a column of selector triggers, one trigger e.g. 10A or 10B per word location, the triggers of a given array being connected as a shift register so that their states can be shifted down one by a " next " operation. Each pair of arrays has a 2-bit configuration shift register 15 or 16 feeding both columns of selector triggers in common, the output of these columns of the first pair of arrays feeding the shift register 16 of the second pair. Input/output registers 5A, 5B, 6A, 6B, 7A, 7B, 8A, 8B link the arrays to buses 3, 4 as shown. The arrays of a given pair store identical data. Corresponding input/ output registers are continually compared, as are corresponding selector triggers, inequality producing an error indication. If a configuration control line 18 is not energized and both stages of configuration shift register 15 or 16 are " zero," the corresponding pair of arrays is isolated from the rest of the system and the connections between the configuration shift registers by-pass the columns of selector triggers in this pair of arrays. If control line 18 is not energized and both stages of the configuration shift register are " one," both arrays of the pair are in operation, whereas if only one stage is " one" the respective array of the pair is operative alone and this leads to an error indication from the comparisons mentioned. The first array of every pair, or the second array of every pair, or both, can be rendered inoperative (isolated) by de-energizing a first or a second of two configure lines or both of them respectively, during a diagnostic mode initiated by the error indication. In the diagnostic mode, the control line 18 can be energized to connect the configuration registers and columns of selector triggers into a single shift register as shown, preventing any by-passing of the selector triggers. Binary control data can be entered into the configuration shift register 15 at 17. The arrays may be non-associative.