BT Cardphone 1A
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
23
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" -
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 ?
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.
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
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.
