
       ICTARI USER GROUP             ISSUE 46                     May 1997

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                     *   m   a   g   a   z   i   n   e   *

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                       I C T A R I   U S E R   G R O U P
       G Greenway, 8 Denmark Road, Reading, Berks, RG1 5PA. 0118 756668
                 http://www.elis.demon.co.uk/ictari/ictari.htm
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                              INDEX FOR ISSUE 46
                              ==================
     
            C:      Fractal Generator
                    System Audio Manager Utility             

            GFA:    GEM Object Functions
                    Resource File Routines        

            MISC:   VT52 Animations
                    Buzzsaw, A Tetris Clone
                    Image File Format Information
                    (Bug-Fixed) Freeware System Audio Manager
                    Current Membership List
                    Index For Issues 1-45          
                           
            STOS:   Another Fractal Program !
                      
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                                   EDITORIAL
                                   =========
                                                                      
      This edition of ICTARI  is a couple of  days late. Sorry. I've  been
  snowed under at work, and even physicists deserve the odd holiday. (Such
  as it was...) I  hope you made it  to the Goodmans shows,  I was at  the
  Birmingham event, and took some ICTARI flyers along with me. I also left
  some with those nice AUKAUG people, who promised to hand them out at the
  London show the next  day. The turnout was  good, apparantly as good  as
  last year, even though the scottish contingent didn't attend, -they  get
  their own show this year. I was a bit dissapointed when I found out that
  the Falcon Mark X is no longer available, but I want to get my hands  on
  a similar beast. A TT clone is just beyond my means at the moment.  What
  with all the  flyering and the  Micromart advert, two  new members  have
  just joined  ! I'll  consider running  the ad'  again. The  last time  I
  updated the  WEB-site  and advertised  it  on  USENET 9Mb  of  data  was
  downloaded the next  day. The site  currently takes up  around 3Mb,  and
  most issues are  around 200Kb  when compressed.  Someone's been  reading
  ICTARI, then. Rather a lot of this  month's disk is taken up by  Jason's
  game Buzzsaw. Rather  a lot  of editing  time has  been taken  up by  me
  playing  it.  Thank's  also  to  Anthony  and  Xav  of  "Kosmic   Phish"
  productuions for the Audio software  (you'll need DMA sound) that  comes
  with this issue. Check out their article in issue 4 of Atari Computing.
    
                             Have Fun,

                                Giles.    
     
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                                CORRESPONDENCE
                                ==============
                                
  From:   Giles Greenway
  To:     Conributors
  Re:     Contributions !

      Thanks to all the contributors in this issue. Stephen Bruce supplied
  The picture formats  info, Theo  Ross the GFA  stuff. It's  a shame  the
  correspondence section is  a bit  quiet. Keep 'em comming...                                                                       
                                                                   
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  From:   Giles Greenway
  To:     Everyone
  Re:     UDO

      Does anyone have a documentation file to write ? I've just used  UDO
  to write a  report in both  RTF (for  use in Macrosoft  Drow) and  LaTeX
  formats. Needless to say the document  looked much nicer done in CS  TeX
  on my ST than it did on the OTHER package. Granted, both files needed  a
  little tweaking, but UDO performed very well. I intend to register soon,
  and I'd recommend it to you. For those  of you who don't know, UDO is  a
  Universal DOcumentation  program, and  handles  loads of  other  formats
  including HTML, ST-Guide and ASCII. Perhaps I'll start using it to  edit
  ICTARI...

    -------------------------------------------------------------------                                      
                                
  From:   Giles Greenway
  To:     Mark Wherry
  Re:     Lattice C

  (Mark has asked me if it's worth getting the latest (last ?) version of  
  Lattice C by HiSoft...)

      It's quite hard to see differences between the later versions of the
  package. Take your query about AES toolbars: The new version of  Lattice
  *did* have the binding,  but I still  had to refer  to the compedium  to
  understand what  was going  on. (You  can still  get the  CD from  16/32
  Systems.) In general, things like Speedo GDOS, AES 4.1 and DSP  bindings
  are there, but  the documentation  hasn't kept pace.  If anything,  it's
  been downgraded, the nice spiral  bound manuals have been replaced  with
  ones with a cheaper binding. If you've got the time and the disk  space,
  you could always play with GCC  and object GEM... Does anyone else  have
  any opinions ?
                                                                                              
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  From:  Jason J Railton
  To:    JNO (whoever that is)
  Re:    Code '$1b'
  
     In the assembly code on ICTARI #45, JNO had an example of printing on
  the screen using GEMDOS.  Part of the string  printed was the byte  code
  '$1b', followed by  the character "Y",  two byte codes  of 45, then  the
  text string.

     This code $1b isn't  a screen centering method,  it's for moving  the
  cursor. 1b is hexadecimal for 27, or the Escape code. The Escape code is
  used as a  standard for printers  and the DEC  VT-52 text terminal  (the
  sort of dumb  terminals that  connect to a  big mainframe  in a  company
  basement) for controlling the screen  and cursor. The ST's TOS  emulates
  this standard for  it's 'console device'  - the screen.  In fact the  ST
  could easily (I suppose) be turned into a dumb VT-52 type terminal  with
  some very simple code. Just feed console (keyboard) input to the  serial
  port, and feed serial  input to the  console (screen). There's  software
  around to do this, though who knows why you'd want to.

  Anyway, enough of history lessons, the  point is that there are a  whole
  set of these  codes. Escape code  27 is always  followed by a  printable
  character, and the case of this  character is important. 'Esc Y' is  the
  code to relocate the  cursor, as used  in the code  JNO supplied. It  is
  followed by row/col co-ordinates. These codes start at the value 32  for
  position 0. This  makes the codes  32 or greater,  so they are  actually
  printable characters. Strangely though, the colour control codes 'Esc b'
  and 'ESC c' are followed by the actual colour code 0-15, so these aren't
  printable.

  The sequence  in  JNO's code  was:  $1b,  "Y", 45,  45,  "Text..."  This
  translates as: Move cursor to row 13, column 13 and print the text. Note
  that the two  45s represent  character code  45, which  is actually  the
  minus sign "-".

  See the file ANI_TEXT.TXT in one of the folders for a full set of  these
  codes.

  Now to the fun  bits. On the mainframes  at Loughborough Universtity,  I
  put a  load of  these codes  in a  file which  was attached  to my  user
  information. Every time someone  looked me up, they  were treated to  an
  animated sequence as the codes moved the cursor around their screen  and
  re-drew images drawn in ascii characters.

  The ZX Spectrum had similar  codes, and you could  even put them in  the
  10-character filenames that you saved  on tape. So, when someone  loaded
  the program the filename  would flash, show up  in colour, or appear  in
  the centre of the screen.

  The great thing  is, you  can put  these codes  in the  text files  that
  accompany anything on  disk, and  when read  from the  desktop, all  the
  codes will  be activated.  You could  have coloured  text, or  move  the
  cursor around the screen. Someone should write a utility to do it...

  I've included some  examples of  text files with  these codes  included,
  along with the STOS Basic listings I wrote to generate them. Just  don't
  put these codes in your ICTARI correspondence, as word processors  don't
  like them very much. And any  file viewing software probably won't  work
  either. Only use them in text files that are intended to be viewed  from
  the desktop.

    -------------------------------------------------------------------

  From:   Giles Greenway
  To:     Jason J Railton
  Re:     VT52 codes

      JNO is our  very own John  Nicholas Oakes !  You're right about  not
  putting odd  codes  in ICTARI.  Don't  put them  in  'net mail  or  news
  messages either, or VERY nasty things  can happen. Those things are  fun
  to play with, though.  ANSI animations are also  quite popular on  those
  OTHER machines.  I've  a utility  to  convert between  the  two  formats
  somewhere... I've always thought  there should be  a VT52 editor.  Maybe
  there is one, I'll  have a look. It  would be a great  way to present  a
  game,  assuming  you  ever  write  one  pedestrian  enough  to   require
  instructions. The Desktop boots up with a nice, lurid backdrop, and  two
  icons. One runs the game, the other provides the instructions,  complete
  with little green aliens running all over the screen...
   
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  From:  Jason J Railton
  To:    Everyone
  Re:    My fractal program 'Formers'

     Apologies to everyone. It  seems the version that  got to the  ICTARI
  disk plotted fractals  in black  ink on  dark blue,  making them  almost
  impossible to see. This is a problem  I've had before, so I should  have
  spotted  it.  STOS  programs  can  sometimes  behave  differently   when
  compiled, particularly where the screen and palette are concerned.

     Anyway, I've sent  in a corrected  version. I've also  looked at  the
  code again and added some comments  and two new fractal forms. One,  the
  S-curve, is what you get if you do the Koch curve but rotate around both
  end points in the same direction, not in opposite directions. The other,
  the Cross, is a fractal form I developed myself.

    -------------------------------------------------------------------
   
  From: Giles Greenway
  To: Jason J Railton
  Re: Fractals

      I thought the choice of colours  was a little stange. I should  have
  said something. Duh. Anyway, I'm afraid some of my own efforts have made
  it into this issue again...                                               
   
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  From:  Jason J Railton
  To:    Everyone
  Re:    Buzzsaw

     Yes, it's finally here. I've been mentioning this game for ages,  and
  I've finally finished it. I really want people to try it and play it  to
  death. I want to  hear about even the  tiniest bugs, or any  suggestions
  you have for improving it. Are the separate levels over too quickly?  Do
  the levels get too hard too soon, or not quickly enough?

     Now, you will like this game. It's sort of like Tetris, but with  the
  inclusion of small furry animals and circular saw blades (yes, it's that
  much fun). And turn up the sound effects...

     Control is  by  joystick (left/right/down,  fire  = rotate),  'P'  to
  pause, 'Esc' to quit a game, and 'CTRL+C' to exit back to the desktop.

     You don't need  instructions. Just  play it. It'll  all become  clear
  within a few seconds of playing  it. There are 10 levels of  difficulty,
  and you can start on any of the first five levels, for when you get  the
  hang of it. I thought of putting a 'next' indicator in, but personally I
  get bored with Tetris because  it just goes on and  on. I can't get  the
  hang of  using the  'next' indicator  properly, and  it annoys  me  when
  people can, and regularly beat me.  So tough luck. Hopefully this  means
  games will be over a bit quicker, so you can let someone else have a go.
  Me, bitter? (No thanks, I'll have a Murphy's :)

     Again, I hope it will work on an unexpanded 520STFM, but it does  use
  a lot of pre-shifted graphics. If it doesn't work from the desktop,  try
  copying it into the AUTO folder of  a disk and booting from it, to  save
  the memory that GEM takes up. If  it still doesn't work, I'll have a  go
  at writing a cut-down version. It's written in STOS, and I really  don't
  know how much memory it takes up when it's running.
 
    -------------------------------------------------------------------
   
  From:   Giles Greenway
  To:     Jason J Railton
  Re:     Buzzsaw

      Buzzsaw is really rather good. If there's any justice in this world
  DEMON's WEB-server will be sent into overdrive when I upload the game !
   
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