A Quick Guide to TASKdata
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(C) 1989 Dr I A Jones


      TASKdata is a multitasking Videotex terminal for the Archimedes
desktop . To use it usefully you will need a machine containing the ARM
chips , the RISC OS operating system , a serial port and a modem , not to
mention a telephone line and some access numbers to a Videotex computer .
The most widely used Videotex computers in Britain currently belong to a
network called PRESTEL . It is possible to dial into this network for a free
but limited demonstration , you should be able to find a local number in the
telephone directory or from directory enquiries to do this .

      A Videotex terminal translates the special codes sent out by a
Videotex computer into a special display often called a VIEWDATA frame . The
characters on this frame are very similar to those that you see on
television as CEEFAX frames and in turn are very similar to the MODE 7
displays offered by BBC / Acorn computers . These frames often include
brightly coloured characters which may flash or even low resolution ( chunky
) pictures . There are also special frames which include software but to use
them you need to translate the characters using a CET decoder .  TASKdata
includes a CET decoder which can either decode while you look at the '
telesoftware ' frames live , or it can decode a recording of the
telesoftware , often called a spooled recording , or spooling .

      When you first click on the TASKdata modem icon ( yes thats what its
meant to be ) you will get a slight pause while the machine code is
assembled and then a small window called TASKdata will open slightly to the
left of the middle of the screen . In the usual way clicking on various
parts of the window will scroll the display or open it up to full size .
Note that the bottom section of the window isn't used unless downloading
software . If you're not sure what all the parts of the window are for
please read your computer manual before proceding .

      As soon as you move the desktop pointer into the window area you can
begin to talk to your modem . If you have a Hayes type modem typing ATD
followed by a number will dial out the number for you . See your modem
manual for details of how to get ' on line ' .

      Sometimes the Videotex computer will want a special message from you
to tell it what your name is and to check that you have paid for your time
on the Videotex computer . These messages are often called ' log on '
messages and since it costs money to use the Videotex computer usefully they
should be kept secret ! TASKdata will warn you when the Videotex computer
wants a log on message by bleeping at you .

      As soon as you are connected you will need to know how to disconnect ,
it's the height of bad manners simply to pull the plug ! Summon up the
TASKdata menu by pressing the middle mouse button with the pointer over the
TASKdata window . At the very bottom of the menu is ' Leave ' , this sends a
special sequence to the Videotex computer to tell it that you want to leave
the system ( in some circumstances though , it will only disconnect you from
a 'gateway ' computer , you will be told in advance by the Videotex computer
when you are being connected to a gateway so don't worry about this ) . If
you now click on ' Leave ' you should be logged off the Videotex computer  .

      If you wish to make a recording of what you did on the Videotex
computer you can use the menu section called ' Filing ' . When you follow
the filing arrow you will be given a choice of ' Read '..ing  an old
recording or 'Writ(e) '..ing a new one . To write a new recording follow the
' Write ' arrow to a box called ' Filename ' . When you are right inside
this box a bright red line will appear and you can type the name that you
want the recording to be called . When you have finished typing the name
click again on this box or press ' RETURN ' on the keyboard . Your recording
has now started . To stop the recording click again on the ' Write ' box .
Note that this has a tick next to it while you are recording .

      To replay a previous recording , you can use the same ' Filing '
system using ' Read ' instead of write or more simply drag the file icon
that you wish to read onto the TASKdata window and drop it there . Note that
reading and writing are quite independant of each other and can happen at
the same time . TASKdata isn't at all fussy about the type of file icon
dropped onto it and will attempt to display almost any file . Usually only
Videotex spoolings will make sense but you could for example use the CET
decoder to get telesoftware out of another programs recording of Videotex
frames , you can do this with ' Hearsay ' frames for example provided these
are in the right order and are complete .

      Another section of the TASKdata menu is called ' Reveal ' , if you
click on this then any hidden text in the Videotex frame will be displayed
to you . Because other multitasking programs may wish to use the function
keys you cannot use these to ' Reveal ' text like in some older systems . '
Reveal ' is cancelled at the start of every frame .

      Occasionally you may get a bad frame picture due to noise on the
telephone line or hiccups on the Videotex computer . You can clear the
screen using ' Clear ' on the menu and then ' Re-display ' the frame free of
charge ( except for time charges of course ) .

      If you want to decode some telesoftware then use ' CET ' on the main
menu and this will decode any telesoftware frames which go to the display
and save them as a file in your current directory using the filename
supplied by the telesoftware frame . You don't have to type one in yourself
and the desktop allows you to change the name later . Be careful though not
to download a frame with a file name the same as one already in your
directory !

      Sometimes when the line is very bad the CET decoder will have to give
up . It does this only after having twenty goes at retrieving a frame and
will warn you with a bleep . If a file is successfully decoded you will hear
two bleeps .

       The final sections of the menu are for setting BAUD rate and parity ,
these are set up correctly for standard Videotex computers when you start up
the program , if you know what they are for you hardly need me to tell you
how to use them !

 
The program and name TASKdata are the copyright of Dr I A Jones 

The program contents and programming methods , where unusual , are the
intellectual copyright of Dr I A Jones .

Any contravention of copyright will be dealt with by expensive lawyers !!

