BT Cardphone 1A

TK12 processor and eprom card

The Phone (not card reader which is another computer) has a PCB marked TK12 Carte Logique, this has 4 eprom sockets, none of which have eproms in them, instead IC 12 has a DIL plug and a ribbon cable leading to a eprom daughter card with 12 x 24 pin dil sockets.

RAM

under the eprom card ribbon

eprom board logic

IC13 -MC14015BCP - DUAL 4 BIT SHIFT REGISTER

IC14 -MC14042B

IC15 - MC14042BCP

IC16- MC14071BCP QUAD 2 INPUT OR GATE

IC17 -MC14515BCP

The 14515 is a 4 to 16 decoder

data 1 - pin 2 = Pin 10 of IC14

data 2 -pin 3 = PIN 11 IC14

data 3 - pin 21 = PIN 1 IC14

data 4 pin 22 = PIN2 IC 13

INHIBIT PIN 23 = PIN 3 OF IC16

The trailing edge of TPA is used by the memory system to latch the higher-order byte of the 16-bit memory address into ic14 and ic 15

this generates A8 for the eproms and A9,A10,A11,A12 for the 4-16 decoder

It also generates A13 bar for ram chip select.

TPA -

The high order byte (A1) of a 16 bit address is output by the 1802 on the MA 0-7.

TPA is then pulsed high to store the high order address bits in a latch

Then MRD is set low

then TPA goes low

Then low order byte of a 16bit address appears on the MA 0-7

TPA, TPB (2 Timing Pulses)

Positive pulses that occur once in each machine cycle (TPB follows TPA). They are used by I/O controllers to interpret codes and to time interaction with the data bus.

The trailing edge of TPA is used by the memory system to latch the higher-order byte of the 16-bit memory address. TPA is suppressed in IDLE when the CPU is in the load mode. MA0 to MA7 (8 Memory Address Lines) In each cycle, the higher-order byte of a 16-bit CPU memory address appears on the memory address lines MA0-7 first. Those bits required by the memory system can be strobed into external address latches by timing pulse TPA. The low order byte of the 16-bit address appears on the address lines after the termination of TPA. Latching of all 8 higher-order address bits would permit a memory system of 64k bytes.

ADDRESS DECODE

PIN 18 - PIN9 IC15 - OUTPUT FROM EPROM BOARD RAM CHIP SELECT

PIN 19 VDD/MRD - PIN 2 IC16 (NOT A10)

PIN 22 E2/CS (NOT A9)- PIN 9 IC 13 , PIN2 OF IC16 NOT A9! :main board ic1 pin 1 and pin 9,ic17 pin9

PIN 23 TPA (NOT A8) - PIN5 OF IC14 & 15 &PIN 7 OF IC13

PIN1 A7 - PIN14 IC15

PIN 2 A6- PIN 13 IC 15

PIN 3 A5- PIN 7 IC15

PIN 4 A4 - PIN 4 IC15

PIN 5 A3- PIN 14 IC14

PIN 6 A2 -PIN 13 IC 14

PIN 7 A1- PIN 7 IC14

PIN 8 A0 - PIN 4 IC14

PIN 4 IC 13 Q1 - PIN 5+6 OF IC16

PIN1 IC 16 = PIN10 IC 15

pin 20 of all eproms comes from ic16 pin 4

1st 4 eproms

In the first 7 of these are intercil im6654IJG eproms, the other sockets are empty. The Intercil IM6654 is an 8 by 512 cmos eprom. So the total software on the card is 3.5k bytes.

There are 9 address lines

A0-A8 giving 512 locations

C1702A is

2716 is 16384 bits

2732 is

Ive Just got this phone into my collection, I'll post here as I found out more about it.

This white model was on tomorrows world .. https://www.facebook.com/BBCArchive/videos/577582255948142/

Birds of a Feather prison card phone

TESTING

Ive powered up my phone from a 24v AC supply and a Testel 200 payphone line simulator.

On picking up the phone, I get a dial tone and "000" flashes on the display.

Inserting a card causes it to be ejected immediately.

Inserting a card upside down causes the reader to move the read head for a second then the card is ejected again.

The phone continues to flash "000"

Thanks to http://www.telephonecardcollector.com/ for the green Fault codes from a more modern card phone

Pressing the test button on the phones logic card causes the display..

0000

1111

2222

3333

4444

5555

6666

7777

8888

9999

1 18

2 8

3 1

4 15

then blank with tones to line and in earpiece

Inserting a card causes it to be ejected immediately. The tones mute for a while the display will then show

Inserting a card upside down causes the reader to move the read head for a second then the card is ejected again.

10 is shown on the display

putting the card in sideways causes

03 if the card jams on the carriage

removing the fuse from the card reader pcb, then running the tests again causes the code

"61" -

Fault codes from a later BT Phonecard phone

after the 1111-9999 count

pressing test again gives

1 18

2 8

3 1

4 15

replacing the fuse causes the "23" and "10" results from card inserts as before

If I manually wind the carriage to the other end, when the card is inserted the carriage returns before exhibiting the same

"23" and "10" results from card inserts.

The interface between the reader and the phone

There are 3 Opto isolators in the reader which seem closely connected to the ribbon cable to the phone.

I could guess 1 is data out 1 data in and perhaps 1 for reset ?

BT Phonecard 1A - Opto isolators in SK30 Land & Gry reader

Both the phone and card reader have a RCA CDP1854CD UART so I would guess the comms between the card reader and phone is some sort of current loop asynchronous serial.

http://www.optical-cards.com/MyImages/1-80_phonocard_GB.pdf says

The interface between the reader and the telephone incorporates the following functions

Recognise valid cards - by verification of the family code
decode the information bits of the type code
command the read and erase processes
command the carriage movement
count the number of value bits erased and by subtraction deduce the balance remaining on the card

The input signals to the reader are

Read command
Erase command
Carriage advance command
Eject card command

The card reader outputs the following information

Card present
Beginning of track
Presence of valid value bit

There must also be error states output from the card reader.

Landis & Gyr Optical Test Cards for BT

Ive looked on the internet for all the testcards i can find and plotted V0 and V1 against the numbers that follow..

They look like straight lines to me.

Graph of BT phone card detector voltage against number

Costs

In November 1988 the "Summary of Charges for Telecommunications Services PH3824" on Page 42 says.

£74 connection, £101.50 Quarterly rental, £115 for new line,£26.75 Quarterly business line rental +£17.00 connection and £2.50 per Quarter for meter pulse.

Eprom Images card reader

The SK30 Card reader has 2 MBM2716 Eproms on a PCB Marked SK.30 carte E

IC 12 is marked Chip 1 and IC 11 is marked Chip 2

The Phone it self has a PCB marked TK12 Carte Logique, this has 4 eprom sockets, none of which have eproms in them, instead IC 12 has a DIL plug and a ribbon cable leading to a eprom daughter card with 12 x 24 pin dil sockets.

In the first 7 of these are intercil im6654IJG eproms, the other sockets are empty. The Intercil IM6654 is an 8 by 512 cmos eprom. So the total software on the card is 3.5k bytes.

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