GB2043399A

GB2043399A - Display apparatus for view data system

Info

Publication number: GB2043399A
Application number: GB7942912A
Authority: GB
Original assignee: General Electric Co PLC
Current assignee: General Electric Co PLC
Priority date: 1978-12-15
Filing date: 1979-12-12
Publication date: 1980-10-01
Also published as: GB2043399B; AU535061B2; NL7908943A; DE2950296A1; DK533479A; AU5383079A; NZ192359A

Abstract

Display apparatus of the kind which is used to display information received over a telephone line from a remote location has a plug-in user's unit 9. Data contained in the user's unit is transmitted to the remote location by the apparatus for the purpose of identifying the user. The user's unit may also include a program to be run by a processor 1 included in the apparatus. Such a program may be used to control the receipt over the line of a larger program from a central computer. The larger program may then be run by the processor after the line to the central computer has been released. <IMAGE>

Description

SPECIFICATION Electronic apparatus for the display of information This invention relates to electronic apparatus for the display of information and is more particularly concerned with display apparatus of the kind in which the information to be displayed is signalled from a remote location in response to a request for that information being signalled bythe apparatus to the remote location.

Apparatus for use at a terminal station of a viewdata system, for example the PRESTEL system operated by the British Post Office, is display apparatus of the kind specified and the invention is more particularly, but not exclusively, concerned with terminal apparatus for such a system.

In the PRESTEL system, for example, the display apparatus at a user terminal is connected to a pair of telephone lines which extend to an exchange of the public telephone network. When the user wishes to call up information from a remote data bank for display, it is necessary for a connection between the display apparatus and the data bank to be set up through the public network. For that purpose the display apparatus is arranged to transmit to line signals (e.g. "dial" impulses or tone signals) characterising the telephone number of the required data bank and that may be done either by the user pressing the appropriate numeric keys of a keyboard or automatically.For the purpose of charging it is then necessary for the apparatus to transmit information in digital form to the data bank giving a password or otherwise identifying the user and this information is preferably a series of alpha-numeric characters. This information may be followed by further information (also preferably a series of alpha-numeric characters) signalled in similar manner to signify to the data bank that the user is authorised to have access to certain data stored thereby. This data could, for example, be in respect of information only available to display by a restricted number of users of the system or a computer program which only specified users are entitled to receive.

It is one object of the present invention to provide improved apparatus of the kind specified.

According to a first aspect of the present invention display apparatus of the kind in which information to be displayed is signalled from a remote location in response to a request for that information being signalled by the apparatus to the remote location in combination with a user's unit capable of being fitted to or engaging with the apparatus as required by the user of the apparatus, said user's unit storing information to be transmitted by the apparatus for the purpose of identifying the user, the display apparatus and the user's unit is fitted to or engaged with the apparatus the apparatus operates to transmit the information stored by the user's unit.

It will be appreciated that the display apparatus and user's unit referred to in the previous paragraph need not be uniquely associated and that a plurality of user's units may be provided each of which may contain the same information (E.G. identifying a group of users) or each of which may be unique to a particular user and containing information identifying the particular user.

Similarly any of the user's units could be-fitted to or engage with any suitably adapted display apparatus.

According to another aspect of the present invention in display apparatus of the kind in which information to be displayed is signalled from a remote location in response to a request for that information being signalled by the apparatus to the remote location in combination with a user's unit capable of being fitted to or engaging with the apparatus as required by the user of the apparatus, said user's unit storing a program which runs under control of processing means of the apparatus.

Preferably, the apparatus contains a further memory, said further memory being of the kind which enables information stored thereby to be altered electrically, the provision for transmitting electric signals to line being arranged to transmit signals in respect of information stored by either of the memories.

The detachable memory may be a semiconductor memory of the kind known as a read-only-memory.

The apparatus may be controlled by a microprocessor which may also be arranged to run programs stored in either of the memories.

The microprocessor may be arranged to run a program in the detachable memory to control the storage in the electrically alterable memory of a program being received over line form the remote location.

The program stored in the detachable memory may be arranged to include a program interpreter such that the information received from the remote location appears to an unauthorised recipient as a string of meaningless characters.

Electronic apparatus in accordance with the present invention will now be described with reference to the accompanying drawings of which:- Figure 1 is a block diagram of known apparatus of the kind specified, Figure 2 is a block diagram of apparatus in accordance with the present invention, Figure 3 is a block diagram of an extended version of the apparatus of Figure 2; and Figure 4 is a flow chart of a typical program stored in a detachable memory of the apparatus of Figure 3.

Referring to Figure 1 a known viewdata terminal is centred around a data bus 2. The terminal is controlled by a microprocessor 1, running a program which is fixed when the set is manufactured in a program memory (3) which may be for example Read Only Memory (ROM). The program controls the other elements of the terminal and will obey commands (for example "Go into Viewdata") from a keypad 4.

Telephone numbers and a user number and password of the terminal are stored in a Data Store (5) which may be for example battery-backed RAM )random Access Memory). A serial interface (6) enables serial communication with a Viewdata com puter (not shown) through a modem (7) via a telephone line (not shown), and display circuits (8) map an area of memory on to a T.V. screen (not shown) in the form of alphanumeric characters and/or graphics symbols. The main drawback of this form of Viewdata terminal is its inflexibility; it will perform a limited range of functions which cannot be extended without dismantling the terminal to change the program memory (3). However, the microprocessor is in essence a general purpose processor, capable of carrying out a wide range of data processing and communication tasks.

In the present inventive Viewdata terminal, there are two further methods of providing additional programs. Referring to Figure 2, at least part of the program memory is in the form of a user's unit (9) which may be changed by the user. The user's unit (9) which may be for example a Read-Only Memory (ROM) may include a short program to perform a specific task and/or may include fixed data to be transmitted to a remote location. Each terminal may be supplied with several interchangeable user's units (9) each containing a program to perform a respective task under control of the microprocessor or containing data which might be a form of password individual to a particular user. This has the advantage of being simple and not requiring complicated loading.

To enable longer or more complex programs to be used a larger capacity program and data store (10) is provided into which programs may be loaded from the remote location, this is more versatile but needs a a loading procedure which is provided in one of the user's units 9.

The simplest terminal according to the invention need only be slightly different from a standard terminal with the fixed program memory 3 being replaced by a suitable socket and plug-in user's ROM unit, for example.

Referring now to Figure 3 in which elements having substantially similar functions to elements of Figure 2 are similarly numbered it may be seen that many other useful features are included in the apparatus.

The program and data store 10 of Figure 2 is replaced by a larger capacity store 11 which may be a dynamic Random Access Memory (RAM). Program and fixed data may be stored respectively in a programmable read only memory store (PROM) 12 and/or in a CMOS memory 13.

Afloppy disc store 14 with a suitable drive and interface circuit 15 provide back-up storage for both program and data.

An input/output interface 16 is also provided and may be connected to (for example) a full keyboard (not shown), a line printer (not shown), cassette recorder (not shown) or may provide interlinking with other computer facilities (not shown).

Referring also to Figure 4 the user's unit 9 may control the receipt of a program from a Viewdata computer, the received program being stored in the RAM store 11 for subsequent running "off line" by the microprocessor 1. This method or working is known as "Telesoftware" and the program which is held in the user's unit 9 is used in the following manner: When a user of the apparatus wishes to run a program which is stored on a central computer (not shown) the user inputs details of the computer centre required by way of the keyboard (not shown).

When this input is detected by the apparatus (100) it enters a viewdata subroutine (110) which fetches the "telephone" number of the computer centre from the RAM store 11. The digits of the telephone number are then sent to line by dial impulses ortone signals under control of the microprocessor 1.

The apparatus then awaits a confirmation signal from the computer centre (120) and, assuming a successful connection, causes the required page number to be transmitted to the computer centre (130). Data transmitted from the computer centre (140) is checked for errors (150) by a parity check for example and, assuming a successful transfer of data, the data is stored in the RAM store 11 (160, 165).

The data received from the computer centre will be terminated by a run instruction which may be sent with an address at which the received program commences (170). The microprocessor then causes the line to the computer centre to be released and runs the program (180).

Although the flow chart of Figure 4 shows an extremely simplified program it will be readily appreciated that the program included in the user's unit 9 may include facilities for security by including for example a descrambling or program interpreting program. Thus the data from the computer centre may not be sent in logical order so that any unauthorised terminal user achieving connection to the pages of the computer centre will not be able to run the program without a suitable program interpreting program of the correct kind.

It will also be realised that the apparatus need not necessarily work in conjunction with a remote computer. For example in a modern office environment several terminals may be provided each selecting its required programs from a local computer and since the execution of the programs is carried out by the microprocessor (1 ) in the apparatus many more terminals may be handled by the local computer since most operations are carried out without the terminals being connected to the local computer.

A system such as that described above could readily meet one of the greatest needs in a modern "electronic" office-that of an integrated data handling system.

For example, if stock information has to be retyped into a word processor and reformatted before it can be printed as a letter to a distributor, much of the advantage of an electronic office is lost. The inventive terminal could, with a suitably programmed user's ROM unit 9, retrieve the data, reformat it, and then print it. If required, it may run word processor softwareforthe user to reformat documents, or, given a standard letter format, it may automatically reformat. The software may also make use of the floppy disc store 4 for example, a list of names and addresses to whom a letter must be sent can be stored on disc and multiple copies of the letter out putto a printer (not shown) with appropriate names and addresses.The dynamic RAM store 11 may accommodate payroll information, stock levels or accounts information. The programs needed to handle format and print this data can be obtained from, and maintained through a Viewdata link from a central computer, the program being loaded to the RAM store 11 by the microprocessor 1 executing a program in one of the user's units 9.

Where the requirement of the user's unit 9 is simply to provide a "password" to enable access to specific information or to identify the user for the purposes of charging for example it will be appreci atedthatthe user's unit may be extremely simple. A small ROM may be used or a mounted magnetic strip for example of the kind used for modern credit cards.

It will be appreciated that the component parts of the display apparatus hereinbefore described are all standard commercially available components. For example the microprocessor may be a Motorola 6800 or an Intel 8085 whilst the input/output device (for use with the Motorola 6800) may be of the kind known as a Motorola 6850.

The user's unit may be any suitably encapsulated commercial two kilobyte (byte = 8 bits) Read Only Memory or Programmable Read Only Memory such as the Intel 2716. When a larger user's unit is required (say four kilobyte) then two suitably mounted ROMs or PROMs may be used.

Any suitable dual-in-line socket may be used as the socket component where ROMs or PROMs are used for the user's unit although it may be desirable to further encapsulate the integrated circuits and provide suitable pin and socket connectors to prevent the user's unit being inserted the wrong way round.

Claims

1. Display apparatus of the kind in which information to be displayed is signalled from a remote location in response to a request for that information being signalled by the apparatus to the remote location in combination with a user's unit capable of being fitted to or engaging with the apparatus as required by the user of the apparatus, said user's unit storing information to be transmitted by the apparatus for the purpose of identifying the user, the display apparatus and user's unit being adapted to cooperate so that when the user's unit is fitted to or engaged with the apparatus the apparatus operates to transmit the information stored by the user's unit.

2. The combination according to Claim 1 in which the user's unit is a read only memory arranged to be fitted to a connector mounted on the apparatus.

3. The combination according to Claim 1 in which the user's unit is a card having at least one magnetic zone and the apparatus includes a reader for such a card.

4. The combination according to any preceding Claim in which any one of a plurality of user's units may be fitted to or engage with the apparatus of each of said plurality of user's units being uniquely associated with a particular user.

5. Display apparatus of the kind in which information to be displayed is signalled from a remote location in response to a requestforthatinformation being signalled by the apparatus to the remote location in combination with a user's unit capable of being fitted to or engaging with the apparatus as required by the user of the apparatus, said user's unit storing a program which runs under control of processing means of the apparatus.

6. The combination as claimed in Claim 5 including an electrically-alterable memory to store a program which runs under control of the processing means of the apparatus.

7. The combination as claimed in Claim 6 in which the electrically alterable memory also stores data for use by the processing means.

8. The combination as claimed in any one of Claims 5 to 7 including provision for transmitting electric signals to line in respect of information stored in the user's unit.

9. The combination as claimed in Claim 8 in which the provision for transmitting electric signals to line also transmits electric signals to line in respect of information stored by the electrically alterable memory.

10. The combination as claimed in any one of Claim 5 to 9 in which the processing means is a microprocessor.

11. The combination as claimed in any one of Claims 5 to 9 in which the information stored in the electrically unalterable memory may be altered in response to electric signals received over a line from a remote location or by the user of the apparatus.

12. The combination as claimed in Claim 11 in which storage of information in the electrically alterable memory is controlled in accordance with a program stored in the user's unit.

13. The combination as claimed in Claim 12 in which the program stored in the user's unit includes a program interpreter for descrambling the information received over the line from the remote location.

14. Electronic apparatus substantially as hereinbefore described with reference to the accompanying drawings.