Browse Prior Art Database

Time Sieve

IP.com Disclosure Number: IPCOM000078568D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Wade, RM: AUTHOR

Abstract

In a very large real-time command and control system, commands are queued for events which the system plans to occur in the future. Each command is associated with a record containing a time stamp indicating when the event is to occur. When the number of records is large, they can neither be kept in high-speed storage (core) nor can they be sorted on direct-access storage in a command service cycle. The solution to the problem involves a series of cascaded files where each member of the cascade, C(N), consists of a file pair, C(NR) and C(NW). C(NR) always is in a read mode; C(NW) is always in a write mode. A distributor continuously writes records on C(NW) which pertain to future time interval, T(F) to T(G). At the same time the distributor reads C(NR) and directs these commands to either C(N-1W) or C(NW).

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Time Sieve

In a very large real-time command and control system, commands are queued for events which the system plans to occur in the future. Each command is associated with a record containing a time stamp indicating when the event is to occur. When the number of records is large, they can neither be kept in high- speed storage (core) nor can they be sorted on direct-access storage in a command service cycle. The solution to the problem involves a series of cascaded files where each member of the cascade, C(N), consists of a file pair, C(NR) and C(NW). C(NR) always is in a read mode; C(NW) is always in a write mode. A distributor continuously writes records on C(NW) which pertain to future time interval, T(F) to T(G). At the same time the distributor reads C(NR) and directs these commands to either C(N-1W) or C(NW). When the time interval, T(G) - T(F), has expired and C(NR) has been read, C(NR) and C(NW) are logically interchanged. Newly generated commands always enter the distributor and are routed to a C(N), according to the difference between the present time and the time when the command is to be executed. The time interval associated with C(N) is farther in the future than that associated with C(N-1). As time passes, those commands for very near future events continuously appear at C(0).

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