GB2019162A - Viewdata modem - Google Patents

Viewdata modem

Info

Publication number
GB2019162A
GB2019162A GB7911050A GB7911050A GB2019162A GB 2019162 A GB2019162 A GB 2019162A GB 7911050 A GB7911050 A GB 7911050A GB 7911050 A GB7911050 A GB 7911050A GB 2019162 A GB2019162 A GB 2019162A
Authority
GB
United Kingdom
Prior art keywords
telephone
mode
viewdata
line
capacitor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7911050A
Other versions
GB2019162B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB2019162A publication Critical patent/GB2019162A/en
Application granted granted Critical
Publication of GB2019162B publication Critical patent/GB2019162B/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/08—Telephonic communication systems specially adapted for combination with other electrical systems specially adapted for optional reception of entertainment or informative matter
    • H04M11/085—Telephonic communication systems specially adapted for combination with other electrical systems specially adapted for optional reception of entertainment or informative matter using a television receiver, e.g. viewdata system

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephonic Communication Services (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Television Systems (AREA)

Abstract

A Viewdata modem which is remotely powered from the telephone exchange and is remotely tested therefrom, and a telephone set are connected to the same line to the exchange, through a bistable switch. Switching between the "telephone mode" and the "Viewdata mode" uses a bistable relay (K) which is switchable between its two states by the discharge of capacitors (Ca and Cb). In the normal state one capacitor (Ca) is charged from the line: to set the station to "Viewdata mode", this capacitor is discharged via the relay (K), whose contact (k) switches the line from the telephone set to the TV receiver, via signal converting means SU. The other capacitor (Cb) is now charged from line, and when the terminal is to be reset to "telephone mode" this other capacitor discharges via the relay (K) to switch the line back to the "telephone mode." This switching between "telephone mode" and "Viewdata mode" can be done locally by the subscriber UM, or remotely from the telephone exchange, W1, 2 e.g. for test purposes. <IMAGE>
GB7911050A 1978-04-06 1979-03-29 Viewdata modem Expired GB2019162B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19782814837 DE2814837C2 (en) 1978-04-06 1978-04-06 Data modem, in particular for teletext operation

Publications (2)

Publication Number Publication Date
GB2019162A true GB2019162A (en) 1979-10-24
GB2019162B GB2019162B (en) 1982-03-31

Family

ID=6036280

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7911050A Expired GB2019162B (en) 1978-04-06 1979-03-29 Viewdata modem

Country Status (6)

Country Link
AT (1) AT376533B (en)
AU (1) AU4548979A (en)
BE (1) BE883286A (en)
DE (1) DE2814837C2 (en)
FR (1) FR2422295A1 (en)
GB (1) GB2019162B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0043697A2 (en) * 1980-07-03 1982-01-13 The Post Office Improvements in or relating to data transmission systems
GB2154393A (en) * 1984-02-16 1985-09-04 Standard Telephones Cables Ltd Telephone subscriber's apparatus
US5007253A (en) * 1988-03-25 1991-04-16 Thomas Rahner Portable lace clipping and shearing apparatus for synchronous operation with a lace-knitting machine
US5125077A (en) * 1983-11-02 1992-06-23 Microsoft Corporation Method of formatting data from a mouse

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7905052A (en) * 1979-06-28 1980-12-30 Nederlanden Staat SYSTEM FOR REMOTE TESTING A MODEM WITH DIFFERENT TRANSMISSION AND RECEIVING SPEED.
DE2931464C2 (en) * 1979-08-02 1981-10-08 Siemens AG, 1000 Berlin und 8000 München Circuit arrangement for connecting a transmission device of a modem to a telephone line
DE2931435C2 (en) * 1979-08-02 1981-10-01 Siemens AG, 1000 Berlin und 8000 München Circuit arrangement for connecting a modem to a telephone line
DE3028236A1 (en) * 1980-07-25 1982-03-18 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt CIRCUIT ARRANGEMENT FOR DISCONNECTING A DATA CONNECTION
FR2487610A1 (en) * 1980-07-26 1982-01-29 Telephonie Ind Commerciale Off-hook condition detector for telephone - has leaf contact switch located in magnetic field of line coupling transformer signals indicating replacement of handset
DE3325676A1 (en) * 1983-07-15 1985-01-24 Hagenuk GmbH, 2300 Kiel Circuit arrangement for connecting a data terminal connected to a modem, and an automatic dialling device, to a subscriber line of a switched system, particularly a switched telephone system
DE3347047C2 (en) * 1983-12-24 1986-06-05 Loewe Opta Gmbh, 8640 Kronach Telephone device with a subscriber device with a decoder for querying and displaying information on a screen, for entering answers and for generating messages of a digitally coded type

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5751308B2 (en) * 1973-12-13 1982-11-01
DE2719827A1 (en) * 1977-05-04 1978-11-09 Licentia Gmbh SYSTEM FOR SELECTING AND PLAYING BACK SCREEN TEXT

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0043697A2 (en) * 1980-07-03 1982-01-13 The Post Office Improvements in or relating to data transmission systems
EP0043697A3 (en) * 1980-07-03 1982-01-20 The Post Office Improvements in or relating to data transmission systems
US5125077A (en) * 1983-11-02 1992-06-23 Microsoft Corporation Method of formatting data from a mouse
GB2154393A (en) * 1984-02-16 1985-09-04 Standard Telephones Cables Ltd Telephone subscriber's apparatus
US5007253A (en) * 1988-03-25 1991-04-16 Thomas Rahner Portable lace clipping and shearing apparatus for synchronous operation with a lace-knitting machine

Also Published As

Publication number Publication date
DE2814837C2 (en) 1980-01-10
AT376533B (en) 1984-11-26
AU4548979A (en) 1979-10-18
BE883286A (en) 1980-11-14
GB2019162B (en) 1982-03-31
DE2814837B1 (en) 1979-05-17
FR2422295A1 (en) 1979-11-02
ATA252679A (en) 1984-04-15

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee