A Quick Guide to TASKdata
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(C) 1989 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 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 (*90#) 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 ' Save as: ' . When you are right inside
this box a bright red line will appear in a small window after the word
"DATAfile" . If you just want to save your session on disc under this name
then use the mouse to drag the blue DATA icon ( picture symbol ) into the
directory that you wish to save the session in ( this is called dragging the
icon into a directory viewer ). Alternatively you can edit the name of the
file to something different , and if you include the path name to the
directory that you wish to save into , you can just click on the "OK" icon
to start the recording . 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 .               

      If you would like TASKdata to pause at the end of each frame while
playing back the recording then you should click on the Pause entry on the
main menu . This remains set until cancelled by a further click on the menu
entry . To step forward to the next frame just click the mouse pointer
inside the TASKdata window .
           
      Sometimes you may wish to send a message to someone using what is
called an electronic mailbox . If you are slow at typing then you will
probably wish to prepare these messages in advance . To do this TASKdata
provides two extra facilities to help . One , again on the main menu ,
allows you to edit the screen . When this happens instead of sending what
you type to the modem , TASKdata will simply put what you type onto the
screen . You can record what you type in just the same way as you would make
a recording of a session on the Videotex computer ( see above ) .

      To send this file you must wait until you have been told by the
Videotex computer that it is ready to receive your message and then you can
go back to the filing box and type in the name of the file that you wish to
send to the computer . TASKdata will then feed the file to the Videotex
computer bit by bit . The "send" file will be closed automatically when it
has all been sent and will warn you with a bleep .

      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 in a file . A mini filer will appear just like the one used to
record sessions , but this time it will hold the name of the program that
you are 'down-loading' . Once again you will either need to drag the DATA
icon to a directory viewer or type in a pathname and click on the OK icon to
start saving the telesoftware file . You could of course edit the name of
the program before doing this . 

      Because programs for computers with the RISC-OS operating system can
be very long it is a good idea to take a precaution against the line going
dead whilst downloading telesoftware . To do this , as well as downloading
the telesoftware file , make a backup recording of the session in the usual
way . If the line to the Videotex computer is then lost do the following ;

1. Close the telesoftware file by clicking on the CET loader entry on the
menu .

2. Close the backup file by clicking on the "Write" entry in the filing box
of the main menu .

3. Play back the recording of the session on the Videotex computer and make
a note of the page number of the last frame of the recording .

4. When it suits you . Play back the recording of the session with the CET
loader switched on . This will put you into the same situation as when the
line dropped . You must now quickly get back onto the Videotex computer and
go straight to the same frame that you finished with . You can now complete
the telesoftware file . You have about three minutes to complete this in .

      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 serial
protocol , 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 !
