GB1486453A - Electronic account metering system - Google Patents

Abstract

1486453 Data processing systems PITNEYBOWES Inc 27 Sept 1974 [16 Oct 1973] 12481/75 Divided out of 1486452 Heading G4A An accounting arrangement, e.g. for printing a postage amount on a label to be attached to an item of mail and for forming a total of the amounts printed, includes a computer which provides signals representing a numeric amount to be printed and an addressable memory which is increased or decreased by the numeric amount when the printer operates. The memory addresing circuitry includes counters to address the memory locations in a fixed sequence. The addressing circuitry receives clock pulses from an oscillator (824, Figs. 13B and 13C, not shown) which are fed to a gray counter (826) which cycles continuously. The output of the last stage of the gray counter passes to a first bi-stable unit (832) and via a gate (830) to a second counter (828). The first bi-stable unit provides an output pulse whenever the gray counter begins its count sequence, this pulse setting a second bi-stable unit (834) which enables the gate (830). Thus, each time the gray counter cycles once the second counter (828) is incremented. The parallel-bit output of the second counter is decoded (836) to select the corresponding location in memory (806). When the second counter has completed one cycle the second bi-stable unit (834) is reset and disables the gate (830). Decoding to select a location takes place only when a signal is received from control logic (842). The memory may be formed of CMOS units and comprises credit balance, total, and item registers. Each register holds in respective locations a binarycoded decimal digit of a corresponding decimal order so that accessing the register locations sequentially allows the digits of a stored amount to be presented in order. The memory feeds an arithmetic unit which adds (or subtracts) the amount fed from the computer to the printer to the amount in one of the registers, the result then updating that register. Whenever printing takes place the credit register is decreased by the amount, the total register is increased by that amount, and the item register incremented by one. The credit register may be increased by a fixed amount when funds are paid to a controlling office. The registers' contents may be displayed if required. Batteries prevent loss of data if the arrangement goes to stand-by status, which occurs if certain voltage levels go out of a preset range. Any arithmetic operation being performed when stand-by status is assumed is completed.