Patent GB-1419192-A (GB)
Title: Data processing system
IPC: H04M15/04
Filed: 1973-10-04
Abstract: 1419192 Telephone metering INTERNATIONAL STANDARD ELECTRIC CORP 4 Oct 1973 [6 Oct 1972] 46409/73 Heading H4K [Also in Division G4]  A data processing system comprises a first cyclic memory (DR 00 , Fig. 1) having a plurality of zones (S 00 , Fig. 2, not shown) for storing first data, a second memory TS 00  having a plurality of cells (C 00 , ..., Fig. 4, not shown) associated with the zones arranged in a first portion (P 0 ) of even numbered cells (C 00 , C 02  ...) and a second portion P 1  of odd numbered cells each cell storing second data (DT x , DC x ) to access the zone of the cyclic memory and data (AM x ) to update the first data, this data being read from the second memory to update the stored first data by reading first one portion of the second memory and then the other portion. As described two drums DR 00 , DR 01  each having 64 zones and 512 tracks (with further drums DR 10 , DR 11  storing the same data for security reasons) store data relating to 281559 telephone subscribers in counters, there being three counters for each subscriber to meter local, adjacent and distant calls. Incoming data from buffers RB 0  ... RB 2n-1  each associated with a subscriber is temporarily stored in a hopper TDH used in common by two processors CP 0 , CP 1 . The data from buffers RB 0 -RB n-1  in the form of a six digit subscriber number, a two digit meter code (representing the type of call) and a two digit number of metering units is first transferred by processor CP 0  to a call buffer memory CBM having associated with each cell a bit of a status word CBSW set to "1" when its associated cell is used. The processor CP 1  performs the same operation on data from the buffers RB n - RB 2n-1 . Subsequently the processor CP 0  examines the status words and for each set of stored data a translation table TT 0  is accessed to derive the drum zone (S ij ), drum track (DT x ) and drum counter address (DC x ) corresponding to the received data. The number of metering units is also translated into a binary number (AM x ) and this information is stored in the second memory (TS 00  for drum DR 00 , TS 01  for drum DR 01 ). The associated bit of the status word CBSW is then reset to "0" and a bit of a status word TSSW associated with the second memory is set to "1". If data is received from two subscribers assigned to the same zone of the drum the information relating to the second is stored in an overflow hopper OH 00  or OH 01  instead of in the second memory. When all the bits of status word CBSW are "0", the processor CP 0  examines the status word TSSW to read sequentially the sections (C ij ) and store in a associated cell (K ij , Fig. 6, not shown) of an addressing table ADT 00 , the drum track and counter addresses. In the corresponding cell of an amount table AMT 00  the number of units (AM x ) is stored. All the data in the second memory is similarly processed and subsequently the data in the overflow hopper is accessed. The processor CP 0  then gives a read instruction to a data channel unit DCU 0  so that using the data in the cells of the table ADT 00  it sequentially reads out the data in the associated counter to cells (K<SP>1</SP> 00  ...) in the table. The number of units (AM x ) is then added to the stored data the result being held in the cells (K<SP>1</SP> ij ). The data channel DCU 0  writes this updated information back on to the drum. Periodically the data stored in the drum is transferred to tape.