Price £1.00
`
`Broadcast Teletext
`
`Specification
`
`September 1976
`
`Published jointly by the
`
`BRITISH BROADCASTING CORPORATION
`
`INDEPENDENT BROADCASTING AUTHORITY
`
`BRITISH RADIO EQUIPMENT MANUFACTURERS' ASSOCIATION
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 1
`Page 1
`
`

`

`Contents
`
`Introduction
`
`ee
`
`Television Data-Lines
`
`sj
`
`..
`
`ge
`
`a
`
`=
`
`S
`
`Organisation of Pagesand Rows.
`
`Page Display
`
`Pm
`
`é
`
`=
`
`Definition of Teletext Terms ..
`
`i
`
`ds
`
`is
`
`Ba
`
`“
`
`eg
`
`ss
`
`Figures
`
`‘c
`
`a
`
`a
`
`s
`
`we
`
`-
`
`sis
`
`a
`
`a6 ke #2
`
`aa
`
`%
`
`de
`
`=
`
`ss
`
`ie
`
`is
`
`i
`
`Fy
`
`is
`
`=
`
`si
`
`os
`
`ae
`
`os
`
`a
`
`1g
`
`as
`
`is
`
`&
`
`-
`
`ia
`
`=
`
`6
`
`Pa
`
`=
`
`T
`
`is
`
`-
`
`<i
`
`7
`
`x
`
`S
`
`ws
`
`we
`
`a
`
`f
`
`a
`
`4
`
`4,5
`
`5,6
`
`6,7,8
`
`« 89,10
`
`a
`
`» i
`
`Ooieeoe
`
`Teletext Data-Lines ..
`
`Data Levels.
`
`a
`
`“s
`
`“a
`
`“
`
`te
`
`“
`
`ais
`
`“
`
`=
`
`“s
`
`és
`
`ms
`
`sé
`
`i
`
`a
`
`ta
`
`.
`
`12
`
`Data Timing
`.. ee ee ee ee ee
`An Approximate Spectrum of a Data Pulse
`An Approximate One-Bit Data Pulse ie aaa
`Synchronisation and Hamming Codes atstart of Page-Header and Row transmissions
`..
`.
`14
`
`eeee ©
`
`2
`
`oe
`3
`
`15
`45
`
`16
`.
`= 7
`
`.
`.
`
`:
`
`18
`18
`
`18
`
`7a,
`7b.
`
`Page-Header Format ..
`Row Format
`..
`a
`
`7
`+
`
`=
`i
`
`m
`#
`
`G2
`ms
`
`Examples of Alphanumerics and Graphics Displays
`Idealised operation of Framing Code
`..
`.
`
`Tables
`
`a i “i
`la. Hamming Code Bytes
`lb. Hamming Codes—tests for odd parity ..
`=
`
`os
`s
`
`a
`
`e
`=
`
`3
`a
`
`or
`
`x
`=
`
`_
`aie
`
`5
`
`“
`=
`
`-
`3
`
`7
`"
`
`=
`7
`
`os
`5
`
`=
`as
`
`we
`=
`
`ws
`va
`
`ze
`‘
`
`=
`3
`
`»
`«
`
`”
`+
`
`”
`“4
`
`Ic.
`
`Hamming Codes—decoding action
`
`a a is ws
`
`sé Ss »
`
`Display Modes and Control Characters ..
`Teletext Character Codes
`..
`és
`=
`
`a
`-
`
`Fe
`“
`
`“
`-
`
`i
`“
`
`ia
`a
`
`si
`a
`
`<i
`“
`
`si
`we
`
`19
`w
`. 20
`
`3.
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 2
`Page 2
`
`

`

`FOREWORD
`
`This document describes the parameters of the Teletext signals transmitted in the
`United Kingdom by the BBC and the Independent Television networks.
`It
`supersedes earlier specifications.
`The BBC uses the name Ceefax and the
`Independent Television Companies the name Oracle for their public information
`services.
`The technical specifications of the Oracle and Ceefax signals are
`identical.
`
`Based on experience gained in the initial years of the transmissions, changes
`been made since
`the first specification published in October 1974.
`have
`Additional Control Characters have been allocated to provide facilities which can
`be used to enhance the display of information. These changes have been made in
`such a way that future transmissions remain compatible with Teletext decoders
`based on the later specification dated January 13th 1976.
`
`Distortions, noise and spurious signals inevitably degrade the signal to a
`greater or
`less extent.
`An important point
`to note is that an increase in
`magnitude of these effects will cause a gradual deterioration in analogue television
`while a digital signal, such as Teletext, can still be decoded until the disturbances
`exceed a critical level. Field studies have confirmed that in almost all cases this
`critical level for Teletext occurs when television reception is already poor.
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 3
`Page 3
`
`

`

`INTRODUCTION
`
`This document defines the Teletext broadcasting system. Much of the detailed information is carried by
`figures and tables. The description is in four sections.
`The first section describes how binary code groups are formed into Data-Lines for inclusion in the tele-
`vision field-blanking interval.
`The second section describes how the control and address information carried on each Data-Line,
`together with the special Page-Header Data-Lines and the sequence of transmission of the Data-Lines, allow
`the Data-Lines corresponding to the Rows of a selected Page to be identified.
`The third section describes how the Character Codes received on the Data-Lines corresponding to the
`Rowsof the selected Page are interpreted to give the Page display.
`The fourth section defines Teletext terms.
`
`i.
`
`TELEVISION DATA-LINES
`
`includes unused lines in the field-
`The television signal
`blanking interval (see Figure |) to allow time for field
`flyback in receivers before each active field begins. The
`duration of this interval is usually 25 lines, and some of
`the later
`lines are used by broadcasters for
`test and
`signalling purposes.
`these unused lines as
`This system can use any of
`Data-Lines.
`Initially lines 17(330) and 18(331) are being
`used but other lines may be used.
`is identified as a
`A line in the field-blanking interval
`Teletext Data-Line by the presence of the Clock Run-In
`(see 1.2.1) followed by the Framing Code (see |.2.2) at an
`appropniate time.
`
`is
`It
`frequency.
`
`444
`
`times
`
`the
`
`nominal
`
`television
`
`line
`
`Data Timing
`1.1.3
`is the peak of the
`The data timing reference point
`penultimate ‘1’ of
`the Clock Run-In sequence (see
`Figure 3). This point has been selected to reduce the
`effect of any transient distortions at
`the start of the
`Data-Line.
`The line time reference is the half-amplitude point of
`the leading edge of theline synchronising pulse.
`The data timing reference in the signal as transmitted
`shall be 12-0 (+0-4/-1-O)us after the line time reference.
`The data
`timing may
`vary
`from Data-Line
`to
`Data-Line.
`
`Data-Line Waveform
`i.1
`as a
`(bits)
`Each Data-Line contains binary elements
`two-level NRZ (Non-Return-to-Zero)
`signal,
`suitably
`shaped bya filter.
`
`Data Levels
`1.1.1
`The binary signalling levels are defined on a scale where
`television black level
`is 0% and white level 100% (see
`Figure 2). The binary ‘0’
`level
`is then O(+2)% and the
`binary ‘1’ level is 66(+6)%. The difference between these
`levels is the basic data amplitude. The data waveform will
`contain overshoots so the peak-to-peak data amplitude
`will exceed the basic data amplitude.
`The basic data amplitude may vary from Data-Line to
`Data-Line.
`
`Bit Rate
`1.1.2
`The binary element signalling rate is 6-9375 Mbit/s (£25
`parts per million).
`
`Data Pulse Shape
`1.1.4
`The spectrum of the generated data pulses, which is the
`product of the spectrum of the basic NRZ data waveform
`and that of a phase-corrected shaping filter, is indicated
`in Figure 4. To minimise intersymbol interference the
`spectrum is
`substantially skew-symmetrical
`about
`a
`frequency corresponding to one-half of the bit
`rate.
`There is minimal energy above 5-0 MHz.
`The
`corresponding one-bit pulse
`Figure 5.
`
`indicated in
`
`is
`
`Data-Line Structure
`1.2
`Each Data-Line comprises 360 bits which may be
`considered as 45 eight-bit Bytes.
`The first three Bytes, which have even parity, serve to
`synchronise the bit and Byte recovery operation in the
`receiver. The remaining 42 Bytes have odd parity and
`carry address and control information, and the codes for
`a Character Row (see Figure 6).
`:
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 4
`Page 4
`
`

`

`The use of odd parity during the variable part of the
`Data-Line ensures that there are never more than 14 bit
`periods between the data level
`transitions in the wave-
`form. This simplifies the recovery of the bit-rate clock
`directiy from the data waveform.
`All the address and Page control information is trans-
`mitted using Hamming Code Bvtes
`to reduce
`the
`possibility of the wrong Character Rows being stored in
`the receiver.
`
`Clock Run-In
`1.2.1
`The first
`two Bytes of every Duta-Line comprise the
`Clock Run-In sequence of alternating bits, beginning
`101010.....
`to indicate the presence of a Data-Line and
`to establish the uming of
`the bits on that
`line (sce
`Figure 6).
`In some circumstances the first one or
`“I's may be absent.
`
`two binary
`
`Framing Code
`1.22
`The third Byte of every Data-Line comprises the Framing
`Code
`11100100.
`This code has been selected
`to
`enable Byte synchronisation to be established even if one
`bit of the Framing Code has been wrongly received.
`Figure 9 indicates how incoming data are compared
`with the Framing Code pattern.
`It shows that a test for
`any seven corresponding bits will give a correct indication
`of the Framing Code in the presence of a single error.
`
`Hamming Codes
`1.2.3.
`The fourth and fifth Byte of every Data-Line, and a
`further eight Bytes of the Pave-Fleader Data-Lines. are
`Hamming Codes containing four ‘message’ bits interleaved
`with four ‘protection’ bits dependent on the message bits
`us
`listed in Table
`Ta,
`The bits are transmitted in
`numerical order from b,
`to be.
`Table tb details four parity tests that can be made on
`the received Byte. Table Ic shows how the results of
`these tests can he used to correct single errors in the
`received Byte and detect multiple errors (when 2,4 of 6
`bits are in error), When there are 3,5, 7 or 8 errors in the
`Byte this procedure results
`in a
`false message being
`decoded.
`.
`Figure 6 shows the locations and lists the functions of
`the Hamming ‘messuge" bits. When error correction is
`all
`used the decoded message bit may differ
`from the
`corresponding bit
`in the Data-line as
`the bits of the
`Hamming Code Byte are interdependent.
`
`Character Bytes
`124
`remainmng Bytes of euch Data-Line are seven-bit
`The
`Character Codes (see Tuble 3) with an added odd-parity
`hit by.
`The bits are transmitted in numerical order
`from b, to bg.
`
`a
`
`ORGANISATION OF PAGES AND
`ROWS
`
`2.1
`
`Addresses
`
`Magazine and Row Address Group
`2.1.1
`Every Data-Line contains two Hamming Codes signifying
`a three-bit Magazine number and a five-bit Row address
`(see Figure 6).
`The Magazine number is in the range 1-8, Magazine 8
`corresponding to the bits 000 and the others being
`directly the number obtained with the bit weights given in
`Figure 6.
`The Row addressis normally in the range 0-23 and it is
`directly the number obtained with the bit weights as given
`in Figure 6. Rowaddresses in the range 24-31 may be
`transmitted but such Data-Lines must be ignored.
`
`Page-Header
`2.1.2
`Data-Lines with Raw address 0 are Page-Headers, which
`contain eight
`additional Hamming Code Bytes with
`message bits relating to that Page, including the two digits
`of the Page number and the four-digit Time Code (see
`Figure 6). The display and control functions of the other
`message bits are detailed in 2.3 below.
`
`Page Identification and Time Code
`2.1.3
`Each Pageis identified by its single digit Magazine number
`(1-8) and its two-digit Page number (00-99).
`Different Pages with the same Magazine and Page
`numbers may be identified by invoking 2 four-digit Time
`Code whereby up to 3200 versions of that Page may be
`individually selected and held.
`The ‘Hours’ and ‘Minutes’ of the Time Code are not
`necessarily related to clock-time. The ‘Hours Tens’ may
`take any value 0-3 and the “Minutes Tens’ may take any
`value 0-7.
`
`Page Selection
`2.1.4
`A Page may be selected by its Magazine number and Page
`number. or by its Magazine number, Page number and
`Time Code.
`Neither type of Page selection should respond to Page
`number ‘Units’ or ‘Tens’ in the range 10-15, and selection
`by Time Code should not respond to ‘Minutes Units’ or
`“Hours Units’ in that range, which may be used for other
`purposes.
`
`Dae
`
`Transmission Sequence
`
`Pages
`2.2.1
`The transmission of a selected Page begins with, and
`includes, its Page-Header and ends with, and exclides, the
`
`a
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 5
`Page 5
`
`

`

`next Page-Header of the selected Magazine number. All
`the
`intermediate Data-Lines
`carrying
`the
`selected
`Magazine numberrelate to the selected Page.
`Pages may be transmitted in any order. Occusionally
`incomplete Pages may be transmitted. Rows from Pages
`of different Magazine number may be
`interleaved in
`time.
`
`Rows
`2.22
`The Rows of a Page may be transmitted in any order.
`Rows,
`including the Page-Header, may be repeated in
`which case the latest apparently error-free information
`should take precedence. Rows containing no information
`for display need not be transmitted.
`
`on a Page designated as a ‘Newsflash’ Page, whether
`or not
`it currently contains
`information.
`All
`information intended for display on such a Page will
`be Boxed (see 3.!.5).
`
`C,—Subtitle Indicator. This Control Bit is set to‘l’ ona
`Page designated as a ‘Subtitle’ Page, whether or notit
`currently contains
`information.
`All
`information
`intended for display on such a Page will be Boxed
`(see 3.1.5).
`
`is set to ‘I’ when
`C,—Suppress Header. This Control Bit
`the Page is better displayed without the characters of
`the Page-Header.
`
`Page Erasure Interval
`2.2.3
`Rows will be transmitted such as to allow an active tele-
`vision field period between an initial Page-Header and
`further Rows sufficient to complete the transmission for
`that Page.
`This allows one display period for the receiver Page
`store to be erased when necessary.
`
`C,—Update Indicator. This Control Bit may be set to ‘l'
`when part or all of a Page contains later information
`than that
`in the previous transmission of the Page
`bearing the same Magazine and Page number. The
`‘Update’ Page
`transmission may be
`incomplete,
`containing only the updated Rows of a Page (see
`2.2.1).
`
`2.3
`
`Page-Header Structure
`
`The Page-Header Data-Lines (see 2.1.2) contain eight
`Hamming Code Bytes in place ofthe first cight Character
`Bytes of the other Data-Lines (see Figures 6 and 7).
`There are thus only 32 Character Codes in a Page-
`Header. They are used to present general information for
`display, such as the Magazine and Page number, the day
`and date and the programme source.
`In particular,
`the
`last eight characters are reserved for the display of clock-
`time. Examples of the content of a Page-Header are given
`in Figure 7a.
`The locations of the 32 address and contro] message
`bits of the eight Hamming Codes peculiar
`to a Page-
`Header are shown in Figure 6. This also shows the binary
`weights of the eight Page number, and |3 Time Code, bits
`whose functions are described in 2.1. The remaining 11
`bits are Control Bits numbered Cy to Cyq whose functions
`are described below.
`
`Control Bits (see Figure 6)
`2.3.1
`is set to “1” when the
`C,—Erase Page. This Control Bit
`information on that Page is significantly different
`from that
`in the previous transmission of the Page
`bearing the same Magazine and Page number, such
`that the two should not be confused,
`Its use will always be followed by a Page erasure
`interval (see 2.2.3).
`
`C,—Newsflash Indicator. This Control Bit is set
`
`to ‘I’
`
`C,—Interrupted Sequence, This Control Bit is set to ‘1’
`when a Page is being transmitted out of strict
`numerical sequence in order to give it priority (such
`as a Subtitle Page) or more frequent
`transmission
`(such as an Index Page).
`It allows the Page-Header to be suppressed when
`Rolling Headers
`are
`displayed,
`to
`avoid
`dis-
`continuities in the displayed Page numbers.
`
`is set to ‘1’ when
`Cjo—Inhibit Display. This Control Bit
`the contents of a Page cannot usefully be interpreted
`as a Teletext transmission.
`It can be used to inhibit
`the display of meaningless Pages.
`
`C,, —Magazine Serial. This Control Bit is set to 1’ when
`the transmission sequence of Magazines and Pagesis
`such thatit is preferable to display all Page-Headers as
`Rolling Headers rather than only those of the selected
`Magazine.
`
`Cy
`Cys
`Cis
`
`these unallocated
`is desirable that
`It
`Unallocated.
`Control Bits be accessible in decoders for future use
`as display control functions.
`
`3.
`
`PAGE DISPLAY
`
`The 24 Rows of a Page are numbered sequentially from
`O (Page-Header,
`top Row)
`to 23,
`The 40 Character
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 6
`Page 6
`
`

`

`Rectangles of a Row are directly related to the 40
`Character Bytes of the corresponding Data-Line, each
`being assumed to be scanned sequentially from left
`to
`night (see Figure 7).
`Every Character Byte contains a Character Code which
`represents either
`a Display Character or
`a Control
`Character. The Control Characters are used to establish
`Display Modes, which may be changed between Character
`Rectangles within a Row.
`The Display Modes determine how a Display Character
`Code is interpreted as a character to be generated in the
`corresponding Character Rectanele of the Page display.
`The Character Rectangles
`corresponding to Control
`Character Codes are generally displayed as Spaces (but see
`395:
`
`3.1
`
`Display Modes
`
`The Display Modes urelisted in Table 2 as complementary
`pairs,
`those on the left are assumed at
`the start of every
`Row. The Control Character Codes listed with each made
`are used to initiate that made.
`Some Control Characters have immediate effect (‘set
`at’)
`in that
`the new mode obtains for and from the
`corresponding
`Character
`Rectangle,
`others
`have
`subsequent effect (‘set after’) when the new mode obtains
`for and from the next Character Rectangle.
`A later
`Control Character takes precedence over an earlier one.
`When a Control Character signifies a change to a mode
`already
`obtaining,
`that mode
`generally
`continues
`uninterrupted throughout
`the corresponding Character
`Rectangle (but see 3.1.3).
`In general the Character Codes of a Row are sufficient
`to define the entire display of that Row (but see 3.1.6).
`The interpretation of the Display Modes is detailed
`below.
`
`3.1.1
`
`Character Ser
`
`Three wverlapping sets of 96 Display Characters are
`available
`for
`the
`interpretation of
`the 96 Display
`Character Codes.
`During the Alphanumerics Mode the Alphanumerics
`Set applies. During the Graphics Mode the Contiguous
`Graphics Set applies during the Contiguous Mode and the
`Separated Graphics Set applies during the Separated
`Mode.
`
`Display Colour
`3.1.2
`the seven colours white, yellow, cyan, green,
`One of
`magenta, red. blue is used to depict the Display Character
`in
`the Character Rectangle.
`Seven pairs of Contral
`Characters are available so that the Display Colour and/or
`the Alphanumerics/Graphics Mode may be changed by a
`
`single Control Character. There is a direct correspondence
`between bits b,, b+, by of these codes and the red, green
`and blue components of the colours.
`
`Background Colour
`3.1.3
`The Background Colour of the Character Rectangles is
`black during the Black Background mode. Whenever the
`new background Control Character 1/13 (see Table 3)
`occurs the Display Colour then obtaining is adopted as
`the Background Colour in the new background mode.
`
`Conceal and Flash
`3.1.4
`the Display
`Two modes
`are provided wherein all
`Characters are displayed as Spaces at certain times. All
`characters
`in the Conceal mode are intended to be
`displayed us Spaces until the Reveal mode is restored after
`a
`time delay in the receiver or by user control. All
`characters in the Flash mode are intended to be displayed
`alternately as they would otherwise be displayed, and as
`Spaces, under
`the control af a
`timing device in the
`receiver.
`
`Boxing
`3.1.5
`All characters intended for display on Newsflash and
`Subtitle Pages will be in the Boxed Mode. which defines
`the part of the Page which is to be inset into the nonnal
`television picture. This inset operation may be controlled
`automatically by the Control Bits Ce or Cx (see 2.3.1).
`Someor all of the rharacrers on any other Pages muy
`be Boxed. the Boxed Mode then defines a part of the Page
`which may be inset
`into the normal
`television picture
`under user control as an alternative to the display of the
`complete Page alone, or superimposed on the picture.
`In order ty give protectian against spurious Boxing,
`two consecutive Star¢ Box Control Characters 0/1] (see
`Table 3) will be transmitted to start the Boxed Mode and
`two consecutive End Box Control Characters 0/10 will be
`transmitted to terminate that mode. The mode changes
`occur between the corresponding :onsecutive Character
`Rectangles.
`
`Double Height
`3.1.6
`Whenever the Double Height mode occurs the information
`in that Row is sufficient to define the display of both that
`Row and the Rowof next higher address. A receiver
`responding to the Double Height mode on a Row must
`ignore any information received for the Row of next
`higher address, but a receiver not responding to this mode
`wil operate normally on both Rows.
`A receiver responding to one or more occurrences of
`the Double Height mode in Row 'R’ will operate as other-
`wise during that Row except
`that
`in every Character
`Rectangle during the Double Height mode only the upper
`half of what would otherwise have been displayed is
`displayed, stretched vertically to fill the rectangle. On
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 7
`Page 7
`
`

`

`Row ‘R+I" the corresponding lower half of each of
`these is similarly displayed.
`The remaining Character
`Rectangles of Row ‘Rt]" are to be displayed as unboxed
`the «
`Spaces
`in
`the
`same Background Colour
`as
`corresponding Character Rectangles of Row ‘R’.
`
`Boxed Mode—The Display Mode in which, under the
`user's control,
`the characters are intended to be inset
`or added to a television picture. When a Newsflash or
`Subutle is transmitted Uhis operation may be automatic
`under the control of Control Bits.
`
`Hold Graphics
`3.1.7
`Generally all Control Characters are displayed as Spaces,
`implying al
`least one Space between rectangles with
`different Display Colours in the same Row. The Hold
`Graphics mode allows a limited range of abrupt Display
`Colour changes by calling for
`the display of a Held
`Graphics Character in the rectangle corresponding to any
`Control Character occurring during the Graphics Mode.
`This Held Character is displayed in the modes obtaining
`for the rectangle in which it
`is displayed, except for the
`Contiguous/Separated Mode which forms part of the
`structure of the Heid Graphics Character.
`The Held Graphics Character ts only defined during the
`Graphics Mode,
`It
`is then the most recent character with
`b,=1 in its character code, providing that there has been
`no intervening change
`in either
`the Alphanumerics/
`Graphics or
`the Normal/Double Height modes.
`This
`character
`is
`to be displayed in
`the Contiguous or
`Separated Mode as when it was first displayed.
`In the
`absence of such a character the Held Graphics Character
`is taken to be a Space.
`
`4.
`
`DEFINITION OF TELETEXT TERMS
`
`Access Time=The time between selecting a Page at
`receiver and the first complete reception of that Page.
`
`a
`
`96 Display
`the
`of
`Alphanumerics Character—One
`Characterslisted in columns 2, 3,4, 5.6 and 7 of Table 3.
`The shapes of the characters are not defined but they
`should all be different and recognisable.
`
`Broadcast Teletext—The information broadcasting system
`defined in this document.
`
`Byte—A group of eight consecutive data bits intended to
`be treated as an entity.
`
`Character Byte—The Byte obtained by appending an odd-
`parity bit to a Character Code,
`
`Character Code—A seven-bit binary number representing
`one of
`a
`set of Display Characters, or
`a Control
`Character.
`
`Character Rectangle—One of the 960 units in the regular
`matrix of 24 Rows of 40 sites in which characters are
`generated in the display of a Page.
`
`Character Row—see Row.
`
`Clock Run-In—A sequence of alternating bits at the start
`of a Data-Line
`to allow a
`receiver
`to achieve bit
`synchronisation.
`
`Conceal—A Display Mode during which all characters,
`although stored in the receiver, are intended to be
`displayed as Spaces until
`the viewer chooses to Reveal
`them.
`
`set of 96 Display
`Set—The
`Contiguous Graphics
`the 64 Contiguous Graphics
`Characters
`comprising
`Characters listed in colury ns 2a, 3a, 6a and 7a of Table 3,
`together with
`the
`32 Blast-Through Alphanumerics
`Characters of columns 4 and 5.
`
`Alphanumerics Mode—The Display Mode in which the
`Display Characters are those of the Alphanumerics Set.
`
`Alphanumerics Set—The set of 96 Display Characters
`comprising all the Alphanumerics Characters.
`
`Background Colouwr—The colour filling the parts of the
`Character Rectangle not occupied by the characteritself
`(see Figure 8), The Background Colour may be black or
`one of the seven Display Colours.
`It may be changed
`within a Row by Control Characters.
`
`32
`the
`of
`use
`Blast-Through Alphanumerics—The
`Alphanumencs Characters of columns 4 and 5 of Table 3
`during the Graphics Mode.
`
`Contiguous Mode—The Display Mode in which the six
`cells of
`the Graphics Characters
`fill
`the Character
`Rectangle (see Figure 8).
`
`Control Bits--Each Page-Header contains 1] Control Bits
`to regulate the display of the Page and its header (see
`2.3.1).
`
`the 32 characters listed in
`Control Character—One of
`columns 0 and | of Table 3. Five of these are reserved
`for compatibility with other data codes. The others ate
`used to alter
`the Display Modes.
`They are usually
`displayed as Spaces (but see 3.1.7). .
`
`Data-Line—One of
`
`the otherwise unused lines of the
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 8
`Page 8
`
`

`

`television field-blanking interval used to carry information
`for one Teletext Character Row. A Data-Lineis identified
`by the Clock Run-In sequence followed by a Framing
`Code at the appropriate time ona line in thefield interval.
`
`Display Character—One of 222 different shapes which can
`be generated in a Character Rectangle as part of a Page.
`There are Alphanumerics Characters to provide text and
`Graphics Characters
`to provide elementary pictorial
`information, There are three sets, the AlphanumericsSet,
`the Contiguous Graphics Set and the Separated Graphics
`Set, each of %% Display Characters, some of which are
`comunon.
`
`bits as indicated in Table |. A single bit error in such a
`Byte can be corrected. Hamming Codes are used for
`sending addre.
`.d control information.
`
`Hold Graphics—A Display Mode in which any Control
`Character occurring during the Graphics Mode results in
`the display of a Held Graphics Character (see 3.1.7).
`
`Magazine—A group of up to a hundred Pages, each
`carrying a common Magazine number in the range 1-8.
`Up to eight Magazines may be transmitted in sequence or
`independently on a television programme channel.
`
`Newsflash Page—A Page in which all the information for
`display is Boxed, and Control Bit Cs is set to allow this
`information to be automatically inset or added to a tele-
`vision picture.
`
`Display Colour—One of the seven colours (white, yellow,
`cyan, green, magenta, red, blue) used to depict a Display
`Character against the Background Colour in a Character
`Rectangle (see Figure 8). The Display Colour may be
`changed within a Row by Control Characters.
`Page—A group of 24 Rows of 40 characters intended to be
`displayed as an entity onatelevision screen.
`Display Mode—The way in which the Character Codes
`corresponding to Display Characters are interpreted and
`displayed depends on Display Modes established by
`previous Control Characters (see Table 2). These modes
`may be changed within a Row, and aninitial set of modes
`is defined for the start of a Row.
`
`are
`in which ull characters
`Flash—A Dispiay Mode
`intended
`ta be displayed alternately as
`they would
`otherwise be displayed, and as Spaces, under the control
`of a tuning device in the receiver.
`
`following the Clock Run-In
`Framing Code—A Byte
`sequence, selected to alow the receiver to achieve Byte
`synchronisation even if one of its bits is wrongly decoded.
`
`different Display
`127
`of
`Graphics Character—One
`Characters
`based on the division of
`the Character
`Rectangle into six cells,
`the cells being Contiguous or
`Separated.
`The corresponding character codes have
`bg=1;
`there is a direct correspondence between the
`other six bits of the code and the states of the six cells
`of
`the Character Rectangle.
`Examples are given in
`Figure 8.
`
`Graphics Mode—The Display Mode in which the Display
`Characters are those of one or other of the Graphics Sets,
`depending on whether the Contiguous or Separated Mode
`obtains.
`
`Page-Header—A Page-Header Data-Line has Row address
`‘O’ and it
`separates the Pages of a Magazine in the
`sequence of transmitted Data-Lines.
`In place of the first
`eight Character Bytes it contains Hamming Coded address
`and control
`information relating to that Page. Thus the
`corresponding top Row of the Page has only 32 Character
`Bytes. These are used for
`the transmission of general
`information such as Magazine and Page number, day and
`date, programme source and clock-time.
`
`Release Graphics—The Display Mode in which Control
`Characters are invariably displayed as Spaces.
`It
`is
`complementary to the Hold Graphics Mode.
`
`Reveal—The Display Mode complementaryto the Conceal
`Mode.
`
`Rolling Headers—The use of the top Row of the Page to
`display all the Page-Headers of the selected Magazine (see
`2.3.1—Magazine Serial) as they are transmitted. This gives
`an indication of the Page transmission sequence while the
`user is watching, or awaiting, a selected Page.
`
`Row—A Page comprises 24 Rows of characters. When
`displayed on a television screen each Row occupies about
`20 television display lines. Each Row is generated from
`the information on one television Data-Line.
`It
`is to
`avoid confusion with television ‘lines’ that Teletext Pages
`are said to contain ‘Rows’.
`
`Graphics Set—see Contiguous Graphics Set and Separated
`Graphics Set.
`
`Hamming Code—In the Teletext system a Hamming Code
`is a Byte containing four message bits and four protection
`
`transmission in
`Row-Adaptive Transmission—Teletext
`which Rows containing no information are not
`trans-
`mitted. This reduces the access times of the system. The
`non-transmitted Rows are displayed as Rows of unboxed
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 9
`Page 9
`
`

`

`black Spaces.
`
`Separated Graphics Set—The set of 96 Display Characters
`comprising
`the
`64 Separated Graphics Characters
`corresponding to the Contiguous Graphics Characters
`listed in columns 2a, 3a, 6a and 7a of Table 3, together
`with the 32 Blast-Through Alphanumerics Characters of
`columns 4 and 5.
`
`Separated Mode—The Display Mode in which there is a
`Background Colour boundary around and between the
`six cells of the Graphics Characters within the Character
`Rectangle (see Figure 8).
`
`Space—A Character Rectangle entirely filled by the back-
`ground colour.
`
`the information for
`Subtitle Page—A Page in which all
`display is Boxed, and Control Bit C,
`is set
`to allow this
`information to be automatically inset or added to a
`television picture.
`
`Teletext—An information transmission system using the
`data and display formats described in sections 2 and 3 of
`this document.
`
`Television Data-Line—see Data-Line:
`
`Time-Coded Page—In addition to a Magazine number and
`Page number a Page may be assigned a ‘Time Code’ of one
`of 3200 numbers arranged as two ‘Hours’ digits and two
`‘Minutes’ digits. This code may be used to select one of
`many Pages, bearing the same Magazine and Page number,
`transmitted in sequence. When the transmission of each
`version of the Pageis isolated or infrequent this code may
`be made literally the ‘Hours’ and ‘Minutes’ of the clock-
`time at which it is transmitted.
`
`Time Display—The last eight characters of every Page-
`Header are reserved for clock-time. A receiver may be
`arranged to display these characters from the Rolling
`Headersto give a clock-time display.
`
`10
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 10
`Page 10
`
`

`

`
`
`
`
`LI-E1EQ)axaiayayayqussod
`
`yquelg-pjely ||\|I|IIi\|1|
`
` |I[saul]$z)euaiuBur
`|
`
`||1I|reanyuy|I
`
`IceOEGIEBIE,
`
`
`
`yeubigya)uolasuy|
`
`
`
`SSNITVWLVOLX31497391¢L‘Old
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 11
`Page 11
`
`
`

`

`oomWHITE
`
`LEVEL
`
`
`een ger tnesohry
`
`Binary ‘1'
`
`
`0% BLACK__—Binary oO
`peel
`cae —
`
`LEVEL SS Sey VES
`
`
`
`waveform
`Data-Line
`:
`Data-Line
`overshoots
`18 (331)
`
`17 (330)
`
`Basic Data
`Amplitude
`
`,
`
`level: O(+2)%
`Binary ‘O'
`Binary ‘1° level: 66(+6)%
`
`:
`e “
`s
`
`Peak-to-peak
`Data Amplitude
`
`FIG.2: DATA LEVELS
`
`+04
`120 _4.9Hs
`DATA
`
`TIMING
`REFERENCE
`
`LINE
`
`TIMING
`
`
`REFERENCE
`
`
`
`
`
` Colour
`
`Burst
`
`Eo
`Sync
`Pulse
`
`|_|.)
`Clock Run-in
`Framing
`Code
`
`FIG.3: DATA TIMING
`
`12
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 12
`Page 12
`
`

`

`AMPLITUDE Ld mn wie centre of
`
`RELATIVE
`
`—— skew-symmetry
`
`shape determined
`by transmission
`
`filters
`
`
`
`FREQUENCY MHz
`
`FIG. 4: AN APPROXIMATE SPECTRUM OF A DATA PULSE*
`
`September 1976
`
`* Based on practice
`current in
`
`1.0
`
`
`AMPLITUDE
`RELATIVE
` Qe PERIODSaal
`
`FIG.5
`
`AN APPROXIMATE ONE-BIT DATA PULSE*
`
`7
`
`PMC Exhibit 2100
`PMC Exhibit 2100
`Apple v. PMC
`Apple v. PMC
`IPR2016-00753
`IPR2016-00753
`Page 13
`Page 13
`
`

`

`
`
`“ALIEUEYDISS
`
`Japeap-abegyc
`
`WDBeYD* 7Fi5ElselallaOly65Bsdy95ee
`
`
`SNOISSIASNVHLMOYONYH30V3H-39VdJOLYVLSLYS3009ONINWWHONYNOILVSINOYHINAS:9‘Old
` peeHabe,We)sede
`
`aguanbaspaidnweiuy85
`sapeay AgydsigHeyuyOlyssaiddng=Ey
`
`
`
`
`jeuagauizebeyyLily
`paesoyeuq«Ely
`yseysmay=945
`sigUONIaIOd[4]
`apagqnag35
`aiepdq|=By
`[w]
`sigJouuO7[ra
`aseaqgFy
`vorpesimosyouASol
`xIOI7)i:===Lt..hrin©4zzgfzEE.gk.of;vs]eon]
`
`
`
`afer]eles]in]affafdefefofofof«fofofJeffofeto}fofJo]:fo]Yo]fol]of
` sapor)Guruueyya|dnostyssauppyMOYPUPaUuNZeheY;
`
`
`
`
`SappyMOYauizebeyyapeBum