CT6000 Moneybox Payphone
Rathdown BABT S/1000/3/E/450712
BT ITEM CODE 870131
British Telecom Inphone moneybox
This Payphone does not need meter pulses or reversals on the exchange line, the microphone is muted untill the A button is pressed when the 10p coin is sent to the money box, and the LCD starts to display the number of seconds left before another coin is inserted.
The Payphone has an Electronic ringer in a compartment of its own in the base.
Your 2 Shillings are inserted in the left most 10p slot
The coin drops into the coin measure / holding unit.
The 10p lifts the silver coloured lever , which is detected by the emitter detector pair, The LCD display changes from COIN to DIAL.
Ear APB R9 Z600, Mic APB M9 Z600
KKA 19,KKA 17 2, 16
The Key to lift the lid to empty the cash box, also acts as a mode switch, two microswitches detect which of four positions the key is in.
Turning the key to the 9 o'clock position releases the lid
At the 12 o'clock position the key can be removed and the phone is a payphone
At the 2 'o'clock position the phone is in owner mode, calls can be made without inserting cash
At the 3 o'clock position the phone can be programmed
A Mercury Tilt switch detects that the unit is on a flat surface
The back of the main circuit board also has many of the other through hole components
The front of the PCB has the LCD and the Hitatchi HD44795 -4 bit micro and LCD driver Surface mount IC
4-Bit Microcontroller-Microcomputer - Expandable to 96 Segments,Ex:20uS,LCDIII
Clock Frequency - Max. (Hz)=500k
Clock Frequency - Min. (Hz)=300k
Min Instruction Length (bits)=8
Max Instruction Length (bits)=16
Memory Addressing Range=2k
Number of Addressing Modes=5
On-Chip RAM (Bytes)=80
On-Chip ROM (bytes)=16k
Number of Interrupt Lines=3
No. of Non-Maskable Interrupts=1
Number of Maskable Interrupts=2
Number of I/O Lines=32
No. of I/O Ports=6
Vsup Nom.(V) Supply Voltage=2.7
The battery connectors are isolated from the rest of the phones circuitry when the battery compartment lid is removed.
The back of the lid looks like this ...