PRIME-44A is popular model of PRIME telephone call billing
machines (TCBM). A caller comes to the call shop &
dials the destination number from a telephone connected
to TCBM. The dialed number is displayed on the TCBM display.
As the called party answers, meter starts & display
shows the call charges during the call period. When the
caller terminates the call, TCBM prints the call bill.