Repertory dialler with variable length circulating store

Claim 2

A digital storage system for storing data in the form of a plurality of data words of variable length comprising a dynamic data store having a circulation loop round which the stored data words normally pass repeatedly as a single block of data without any gaps between words in the block, circuit means to add a data word to the end of the block of data circulating round the loop, erasure means temporarily to interrupt said loop to erase a data word stored by said store, and close-up means responsive to operation of the erasure means to leave a gap in the block of data circulating round the loop temporarily to produce a predetermined variation in the effective length of the loop for a period less than that in which said block of data passes round the loop during each of the succession of passes so as to reduce the gap during each such pass until the gap has closed up.

Claim 3

A digital storage system according to claim 1 wherein said close-up means comprises a loop extension, means to connect the loop extension into the loop at a particular point as the end of the data block passes that point and means to remove the loop extension from the loop when at least part of the gap is stored by the loop extension.

Claim 4

A digital storage system according to claim 1 wherein said data store comprises shift register means and a feedback path connected between the output and input ends of the shift register means.

Claim 5

A digital storage system according to claim 3 wherein said close-up means comprises further shift register means, circuit means to connect said further shift register means into the feedback path temporarily to extend the length of the loop and circuit means operable subsequent to operation of the last-mentioned circuit means to remove said further shift register means from the feedback path and thereby restore the loop to its normal length.

Claim 6

A digital storage system according to claim 3 wherein said close-up means comprises further shift register means, circuit means to connect said further shift register means into the feedback path as the end of the data block passes through the feedback path, and circuit means to remove said further shift register means from the feedback path when at least part of the gap is stored by the further sHift register means.

Claim 7

Apparatus for use with a telephone instrument for supplying signals to line characteristic of a party to whom connection is required comprising shift register means, a feedback path connected between the output and input ends of the shift register means to form a circulating main data store for the storage of a plurality of data words which normally circulate in the store as a single block of data without any gap between words and each of which words include a digital address and digital information in respect of another party to whom connection may be required, a plurality of manually-operable calling means, address means to supply an associated digital address signal upon operation of any one of said calling means, a further data store, comparison means to compare the address of the signal supplied by the address means with the addresses of words circulating in the main data store, circuit means operable upon address identity being detected by said comparison means to write into the further store the digital information of the word circulating in the main data store having the appropriate address, signal generating means to supply electric signals for transmission to line in respect of the digital information stored by the further store, switch means, erasure means temporarily to interrupt the feedback path upon operation of the one of said calling means subsequent to operation of said switch means to erase from the main data store any word previously stored thereby having the address of the signal then supplied by the address means in response to operation of the appropriate calling means, and circuit means operable upon a word being erased by the last mentioned means to close up any resulting gap in the data block circulating in the main data store, the last mentioned means comprising further shift register means and circuit means selectively to connect said further shift register means in said feedback path to effect a temporary variation of the storage capacity of the main data store for a period less than that in which said block of data passes around the store so as to reduce the gap on each such pass.

Claim 8

Apparatus for use with a telephone instrument for supplying signals to line characteristic of a party to whom connection is required comprising shift register means, a feedback path connected between the output and input ends of the shift register means to form a circulating main data store for the storage of a plurality of data words which normally circulate in the store as a single block of data without any gap between words and each of which words include a digital address and digital information in respect of another party to whom connection may be required, a plurality of manually-operable calling means, address means to supply an associated digital address signal upon operation of any one of said calling means, a further data store, comparison means to compare the address of the signal supplied by the address means with the addresses of words circulating in the main data store, circuit means operable upon address identity being detected by said comparison means to write into the further store the digital information of the word circulating in the main data store having the appropriate address, signal generating means to supply electric signals for transmission to line in respect of the digital information stored by the further store, switch means, erasure means temporarily to interrupt the feedback path upon operation of the one of said calling means subsequent to operation of said switch means to erase from the main data store any word previously stored thereby having the address of the signal then supplied by the address means in response to operation of the appropriate calling means, and circuit means operable upon a word being erased by the last mentioned means to close up any resulting gap in the data block circulating in the main data store, the last mentioned means comprising further shift register means and circuit means selectively to connect said further shift register means in said feedback path to effect a temporary variation of the storage capacity of the main data store for a period less than that in which said block of data passes around the store so as to reduce the gap on each such pass.

Claim 9

Apparatus according to claim 6 wherein said signal generating means is an impulse generator which supplies trains of impulses to characterise the digital information stored by said further store.

Claim 10

Apparatus which is for use with a telephone system comprising shift register means, a feedback path connected between the output and input ends of the shift register means to form a circulating main data store for the storage of a plurality of data words which normally circulate in the store as a single block of data without any gap between words and each of which words include a digital address and digital information in respect of another party to whom connection may be required over the telephone system, a plurality of manually-operable calling means, address means to supply an associated digital address signal upon operation of any one of said calling means, a further data store, comparison means to compare the address of the signal supplied by the address means with the addresses of words circulating in the main data store, circuit means operable upon address identity being detected by said comparison means to write into the further store the digital information of the word circulating in the main data store having the appropriate address, circuit means to supply electric signals for transmission to line in respect of the digital information stored by the further store, recording means operable to enable a data word associated with one of said calling means to be written into the main data store, a plurality of manually operable data means, means operable subsequent to operation of the recording means to add to the end of the data block circulating in the main data store a word having an address determined by operation of the appropriate calling means and digital information determined by operation of a plurality of said data means, Circuit means operable upon operation of one of said calling means subsequent to operation of said recording means and for the purpose of writing a new data word into the main data store to erase from the main data store any word previously stored thereby having the same address, and circuit means operable upon a word being erased by the last mentioned means to close up any resulting gap in the data block circulating in the main data store, the last mentioned means comprising further shift register means and circuit means selectively to connect said further shift register means in said feedback path to effect a temporary variation of the storage capacity of the main data store for a period less than that in which said block of data passes around the store so as to reduce the gap on each such pass.

Claim 11

Apparatus which is for use with a telephone system comprising shift register means, a feedback path connected between the output and input ends of the shift register means to form a circulating main data store for the storage of a plurality of data words which normally circulate in the store as a single block of data without any gap between words and each of which words include a digital address and digital information in respect of another party to whom connection may be required over the telephone system, a plurality of manually-operable calling means, address means to supply an associated digital address signal upon operation of any one of said calling means, a further data store, comparison means to compare the address of the signal supplied by the address means with the addresses of words circulating in the main data store, circuit means operable upon address identity being detected by said comparison means to write into the further store the digital information of the word circulating in the main data store having the appropriate address, circuit means to supply electric signals for transmission to line in respect of the digital information stored by the further store, recording means operable to enable a data word associated with one of said calling means to be written into the main data store, a plurality of manually operable data means, means operable subsequent to operation of the recording means to add to the end of the data block circulating in the main data store a word having an address determined by operation of the appropriate calling means and digital information determined by operation of a plurality of said data means, Circuit means operable upon operation of one of said calling means subsequent to operation of said recording means and for the purpose of writing a new data word into the main data store to erase from the main data store any word previously stored thereby having the same address, and circuit means operable upon a word being erased by the last mentioned means to close up any resulting gap in the data block circulating in the main data store, the last mentioned means comprising further shift register means and circuit means selectively to connect said further shift register means in said feedback path to effect a temporary variation of the storage capacity of the main data store for a period less than that in which said block of data passes around the store so as to reduce the gap on each such pass.

Claim 12

A digital storage system for storing data in the form of a plurality of data words of variable length comprising a dynamic data store having a circulation loop around which the stored data words normally pass repeatedly as a single block of data without any gaps between words in the block, circuit means to add a data word to the end of the block of data circulating round the loop, erasure means temporarily to interrupt said loop to erase a data word stored by said store, and close-up means to close up the gap in said block of data resulting from operation of the erasure means, said close-up means comprising bistable means that is set to a predetermined state subsequent to operation of the erasure means, a shift register for storing a small number of digits that is less than the number of digits of a complete data word, first circuit means operable when the bistable means has been set to said predetermined state to connect the shift register into the circulation loop at a particular point as the end of the data block passes that point, second circuit means subsequently to remove the shift register from the circulation loop when part of the gap is stored thereby, and means responsive to the remaining gap having only a digital length equal to the storage capacity of the shift register to reset the bistable means so as to prevent further operation of the first circuit means, this situation occurring after the first and second circuit means have been operated a plurality of times at each of which the gap has been reduced.

Claim 13

A digital storage system for storing data in the form of a plurality of data words of variable length comprising a dynamic data store having a circulation loop around which the stored data words normally pass repeatedly as a single block of data without any gaps between words in the block, circuit means to add a data word to the end of the block of data circulating round the loop, erasure means temporarily to interrupt said loop to erase a data word stored by said store, and close-up means to close up the gap in said block of data resulting from operation of the erasure means, said close-up means comprising bistable means that is set to a predetermined state subsequent to operation of the erasure means, a shift register for storing a small number of digits that is less than the number of digits of a complete data word, first circuit means operable when the bistable means has been set to said predetermined state to connect the shift register into the circulation loop at a particular point as the end of the data block passes that point, second circuit means subsequently to remove the shift register from the circulation loop when part of the gap is stored thereby, and means responsive to the remaining gap having only a digital length equal to the storage capacity of the shift register to reset the bistable means so as to prevent further operation of the first circuit means, this situation occurring after the first and second circuit means have been operated a plurality of times at each of which the gap has been reduced.