Projects/Payphone

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Voorzijde Kimus2.jpg
Project Payphone
Name Payphone
Start 2022/02/12
End
Contact User:Hillebrand
Website
Information Repair, restore and document a old 1980's payphone to be used to be used as a novelty wall-mounted phone
Status Alpha

I acquired a old nl:PTT Telecom payphone, type Kimus/Kimas (the name differs, most sources I found called it 'Kimus', but it is stamped as 'Kimas' into the identification plate. I will call it Kimus from now) 2.

It was manufactured somewhere in the mid/late 80's, according to chip dates.

General overview

  • Comparable to the German Club Telefon 1. Some parts are interchangable.
  • Dialing using both DTMF and pulse dialing, respectively TDK and IDK in Dutch telephony jargon.
  • 2 coin inputs on the front, for 0.25 NLG coins ('kwartjes') and 1 NLG coins.
  • Amplifier, can be operated using a button on the front
  • Separate power supply, 45-60VAC (optional)

Features

Settings

File:Programmeerblokjes Kimus2.jpg
The Kimus2 'programming blocks'.

The Kimus 2 can be set up by a technician using a few plastic 'programming blocks'. Their meaning is noted on a sticker on the inside of the device.

[File:Instelmogelijkheden Kimus2.jpg]

(008 was the former information service)

Translated:

  • P1 x 10 = Impulse price (tens of cents)
  • P2 x 1 = Impulse price (single cents)
  • P3 x 25 = Minimum coin insertion
  • P4 x 25 = Internal timekeeping (seconds)
  • P5 x 25 = Surcharge per call
P6 Free numbers Free numbers
008 008 TDK IDK
No money Money Payment No payment
0 X X X
1 X X X
2 X X X
3 X X X
4 X X X
5 X X X
6 X X X
7 X X X

I do not know what 'Internal timekeeping' does. I speculate that 'Free numbers' with/without money means that calling free phone numbers requires money to be inserted. Probably to deter prank calls.

Test features

There is a button on the main PCB. Pressing this button will cycle through some test features, described below.

Testfuncties Kimus2.jpg

P6 Free numbers Free numbers
008 008 TDK IDK
No money Money Payment No payment
0 X X X
1 X X X
2 X X X
3 X X X
4 X X X
5 X X X
6 X X X
7 X X X

Wiring

File:Schroefklemmen voor draden Kimus2.jpg
The screw terminals for a external bell, power, and the phone line.

For the bell to operate, the second connector from the top MUST be connected to the connector below (where the jumper is in the photo).

The 48-60VAC is optional. I speculate that it was used for phone booths with a large distance to the exchange, resulting in a low line current, which might cause the electronics to work improperly. My SPA112 ATA seems to supply sufficient current to ring the bell.

The E wire is earth. Needed if you want to simulate cost pulses.

Repairs

Done

Keypad trace repair

[File:Keypad PCB met nieuw soldeer Kimus2.jpg]

There was some stubborn green stuff (probably mold due to water ingress) on the bottom of the keypad PCB. Removing it required a coarse brush, and accidentally severed some traces. They were repaired using some solder.

To-do

Lock replacement

Bij een ijzerhandelaar informeren of ze een SCR0031 (2 maal) van Anker Slot hebben. https://nl.farnell.com/multicomp/s286b-1/keyswitch-spdt-2pos-rdm-1keypull/dp/1735374?ost=1735374 als vervanging voor het 'gratis bellen' slotschakelaar

Help needed

More info on the technical workings of the Kimus 2 (manuals etc) are very welcome. Romdumps and high quality pictures of the Clubtelefon 1 are also very welcome.

If you are more familiar with reverse-engineering bytecode from ancient MCU's, please get in touch.

I can be contacted at flimpie аt bitlair ԁоt nl.

Pictures needed

(just for my own reference, no need to send pics of your own device)

  • Programming plugs on the inside of the door

Pictures

Useful resources

[1] [2] [3]