Turnbull China Bikeride/Turnbull China Bikeride - Disc 2.iso/STUTTGART/FROMUTS/TASKDATA/!TASKdata/Help

Text File | 1989-12-30 | 16KB | 320 lines

A Quick Guide to TASKdata
-------------------------

(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 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 that's what its
meant to be ) you will get a slight pause then a large window called
TASKdata will open on the left 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 . 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 ' Save as: '. If you just want to save your
session on disc under the name DATAfile then use the mouse to drag the blue
DATA icon ( picture symbol ) into the directory viewer 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 by clicking on the word
DATAfile , 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 too 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 panel appears which displays how much of the
telesoftware file has been received and , when the first frame of the file
has been received , 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 .

      Another section on the main menu brings up a keypad panel to the right
of the main display . This will send numeric characters together with * and
# to the modem under the control of the mouse . Clicking on DIAL will send
the modem a special sequence of characters which make it auto-dial if it has
this facility . After clicking dial you must enter the telephone number
followed by ENTER (or RETURN on the main keyboard ) .

       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 !


For The Adventurous
-------------------


Configuration
-------------

     This new version of TASKdata differs from older versions in that it has
a much larger display which is produced by sprite plotting , it contains a
rudimentary program interpreter and the RunImage is in object code format
only .
     On startup the program looks for the file config and loads it into
memory . It then reads the file and interprets any commands present . There
need be no commands present as TASKdata assumes default values . At present
the interpreter understands commands which set : the on screen font ; start
up BAUD rate ; start up protocol ; sequence to initiate auto dialling ;
sequence to terminate auto dialling .

!FONT <filename>
----------------

     If this command is present then <filename> becomes the display font on
start up . This should be of the same format as Newsprite and Courier with
the basic character size 12 * 8 pixels . Feel free to design your own .
Newsprite is based on the system font and is sort of sans-serif whereas
Courier has the same sort of serifs as a typewriter . Courier tends to be
easier to read on low resolution monitors ( or eyes ) . The path name to the
file must also be included so that , for example , with an italic font in
the !TASKdata directory you would use

      eg .   !FONT <TASKdata$Dir>.Italic

!<BAUD>
-------

     With this command present then <BAUD> becomes the start up BAUD rate .
The default is V23 but any of the following are valid .

      eg .   !V22bis   ( 2400/2400 )
             !V22      ( 1200/1200 )
             !V23      ( 1200/75 )
             !RV23     ( reverse V23 )
             !V21      ( 300/300 )

!<Protocol>
-----------

     With this command present then <Protocol> becomes the start up protocol
. I use the term protocol here to lump together start bit , data bits ,
parity bit and stop bit(s) . The default is 7E1 but any of the following are
valid .

     eg .    command    data bits  parity  stop bits

              !7E2         7        even       2
              !7O2         7        odd        2
              !7E1         7        even       1
              !7O1         7        odd        1
              !8N2         8        none       2
              !8N1         8        none       1
              !8E1         8        even       1
              !8O1         8        odd        1

!PREDIAL <string>
-----------------

    With this command present <string> is sent to the modem when the DIAL
icon is clicked on the keypad . The default string is ATD for Hayes modems
but any other sequence of up to 15 characters is acceptable . The sequence
should end with a trailing space . The sequence |X is treated as the single
character X-ASC"@" .


    eg .   !PREDIAL  ATDT

!POSTDIAL <string>
------------------

    With this command present <string> is sent to the modem when the ENTER
icon is clicked on the keypad . The default string is |M  or [13] . The
sequence should end with a trailing space .


    eg .   !POSTDIAL  |M

!LOGON <string>
---------------

    This command causes <string> to be sent to the modem in response to the
ENQ character being received by the terminal . This effects an auto logon .
It is advised that your complete log on ( of 14 characters for Prestel )
should never be stored in a config file . The sequence should end with a
trailing space .

    eg .    !LOGON 4444444444


Bits and pieces
---------------

     The CET downloader of this version has been modified to read a cyclic
redundancy check escape sequence . This takes the form |cXXXX|I or |CXXXX|I
, where |c or |C introduces a 16 bit hexadecimal format number XXXX and |I
terminates the escape sequence in the usual manner . This ensures that all
correctly written software which is unable to interpret the sequence should
ignore it correctly . The cyclic redundancy check is initialised by the
sequence |A in the same way as the checksum but the crc escape sequence must
appear before the checksum escape sequence in order to be used in preference
so a typical frame might end with the sequence |c1AFB|I|Z102 . The crc is
performed on all data up to and including the |c or |C sequence , this is in
order to cover the eventuality of this sequence itself being corrupt and
entering the crc routine in error . I can supply a suitable frame generator
for the Archimedes .

     Note that this is not part of the official CET telesoftware definition
but it may be added later if it proves successful . Note that CRC provides a
much more reliable form of error checking than a 7 bit checksum .

     This version of TASKdata has also been modified to display Viewdata
format files correctly . This is the format used by Hearsay so you can
replay your Hearsay recordings in TASKdata .

     The program is public domain but the source code for this version is no
longer part of the public domain ! If you have modified your own versions of
TASKdata and forgot to tell me then hard cheese , you had plenty of time .
If you require the source code to modify eg. the key translation table !
then you can consult with me on Prestel and cross my palm with silver !

     If you have strong preferences for new features you would like to see
in subsequent versions then again consult with me on Prestel .

     Under consideration for future versions are ;

   a ) Support for ARCcomm mailbox files
   b ) A less duff screen editing system
   c ) Support for intelligent modems such as

        i . Hardware detection of online / offline status

   d ) Telephone address , number and logon store .
   e ) Full programming system .
   f ) Advertising ?

Thanks to ;

Peter Gaunt
Hugo Fiennes     ( ALT-MAN )
James Noad
Richard Forster  ( Arthur Dent )

     Hearsay is copyright of David Pilling
     David Pilling is copyright of BEEBUG

COPYRIGHT 1989 Ian Andrew Jones  . PRESTEL MBX 011156102