
       ICTARI USER GROUP             ISSUE 45                 April 1997

              ___   ______     ___       _________   _________   ___
              \__\  \   __\    \  \__    \______  \  \   _____\  \__\
                ___  \  \       \  __\     _____\  \  \  \         ___
                \  \  \  \       \  \      \  ____  \  \  \        \  \
                 \  \  \  \_____  \  \____  \  \__\  \  \  \        \  \
                  \  \  \       \  \      \  \        \  \  \        \  \
                   \__\  \_______\  \______\  \________\  \__\        \__\

                     *   m   a   g   a   z   i   n   e   *

     =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
                       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
     =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

                              INDEX FOR ISSUE 45
                              ==================

            ASSEMBLY:      Parallax Scrolling Demo.
                           GEMDOS Query.

            C:             Article About AES Messages.

            GFA:           Composed Character Routines.

            MISC:          (Yet Another !) Sierpinski Gasket Demo.
                           WEB-DESK, -Load WWW Pages From The Desktop.
                           ICTARI HTML files.

            STOS:          Scaling Sprites Demo.
                           Iterated Fractal Program.

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

                                   EDITORIAL
                                   =========

   Before  making any efforts of my own, it seems that ICTARI is starting to
   be  noticed  again. ST Applications has some catching up to do, -the last
   issue  mentions that ICTARI 39 is on the web-site. The site has also been
   given  a rather luke-warm review in Atari Computing, although some rather
   nice  things  were  said  about  the  magazine itself. I've only made one
   serious  attempt  to really update the site since I became editor, before
   that it was just a convenient way for overseas readers to get hold of the
   magazine. In  some  ways I'm quite happy with the pages rather minimalist
   look, at least they download nice and quickly, and I certainly don't like
   the  idea  of using HTML frames. On the other hand, the only way visitors
   to  the site can get the flavour of the magazine is to download and unzip
   one  of  the issues. I've had a go at converting the text from this issue
   into  HTML,  and  placed  it on the WEB site. If this is a success I will
   continue to make sure that the current issue can be read on-line, as well
   as  downloaded.  Any  suggestions as to how the pages can be improved are
   welcome.

                        See you at the Goodman's shows,
                                   Have Fun,
                                    Giles.

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

                                CORRESPONDENCE
                                ==============

   To:      Everyone
   From:    Giles Greenway
   Re:      Contributions

        Contributions  are  starting  to  come  to  ICTARI  at  a  rate  I'm
   comfortable  with,  but they seem to be coming from the same people. This
   is fair enough, because I think it's these people who seem to benefit the
   most.  Mark  Wherry's  Magic  documentation problem has been addressed by
   Charles  Ayres, who in return has a small request of his own. Does anyone
   still  remember  the board game Sorry ? A version of the game was written
   by  a  Paul Bonnette using GFA BASIC. Charles' copy has become corrupted,
   and  it  also  seems  that  so  has  everyone  else's ! FloppyShop have a
   corrupted  disk, can anyone supply him with a working version ? Don't try
   looking  on  the  Suzy  B or Compendium CDs, 'cos I already have, and the
   files  are  corrupted  too,  as  are the ones on the Umich FTP archive. I
   believe  the author released the source code a while ago. Goodman's don't
   seem  to  stock  the  game. If I remember rightly the South-West software
   library was closed due to various legal wranglings with Spears Games over
   a scrabble program, so public domain librarys might be reluctant to stock
   this sort of thing.

        Mark  has  also  been  looking for some information about the use of
   toolbars  in  version  4.1  of the AES. It turns out that I may have some
   answers.  I've  recently  upgraded  to  the  latest version of Lattice C.
   Although  there is little mention in the manuals, the various headers and
   librarys  seem  to  have  been updated. Here the constants that have been
   #DEFINED that relate to toolbars:


            WM_TOOLBAR     37
            WF_TOOLBAR     30
            WF_FTOOLBAR    31
            WF_NTOOLBAR    32

        Now,  perhaps  someone  could  give  me  a hand. I sometimes use the
   AT-ONCE+  286 emulator. It works fine on DOS-based programs like Prospero
   compilers, GW BASIC and even Fractint, but I can only seem to run Windoze
   3.0  in  real mode. No matter how much I fiddle with the file SYSTEM.INI,
   trying  to use standard mode just locks up the machine. I keep saying STs
   are more fun ! Can anyone help ?

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

   To:      Giles Greenway
   From:    Louis Maule-Cole

     Dear Giles,
        First  of  all thank you very much for being brave enough to respond
   to  my plea for help. As I said, I am very much a beginner at programming
   and  finding  it  very difficult to get explanations as to how to achieve
   the  effects  that  I want in my applications. I am not a gardener either
   but when one retires and has a garden that requires attention, it becomes
   a necessary evil. My problem is that I kneed to know what there is in the
   garden  and  where  it is and what has to be done to look after it. There
   appears  to  be  no  application  on  the  ATARI market that specifically
   addresses the gardener and so I found myself a project.

        If  a warning appeared to say that no data file could be found, this
   was  because  the file DATBEDS.DAT was missing. If this is so the program
   promptly  creates  a new one. This file contains the coordinates of every
   plant  in it's bed so if the garden hasn't yet been planted up i.e. its a
   new garden, there will be no data file. On the other hand it may have got
   lost, in which case you are in dead trouble! So in your case it is OK.

        Now -- silly me!! I did write a documentation file but I must  have
   forgotten to include  it in the  folder. Being green  at the business  I
   have probably used the wrong terminology by asking for a beta test. What
   I intended  was that  someone be  kind  enough to  use the  program  and
   feedback some constructive criticism. Now  your remark about the use  of
   DEGAS .PI? files being a problem for TT and Falcon owners is the sort of
   thing which I need but why and what  does one do to correct it ? One  of
   the problems with the original GARDEN program was that when I created my
   own DEGAS picture file, it displayed  it shifted by half a screen  width
   so that the left half was on  the right and divided from the right  half
   which started  in the  middle of  the  screen. I  haven't yet  found  an
   explanation as to  how to display  the various picture  formats. My  own
   trial and error solution was to ignore the pre-amble in the picture file
   and read only the picture related words. My only reference at the moment
   is a C file of  'DOODLE' but this only  tackles the subject of  drawing,
   knowledge which I used to incorporate  a crude drawing facility in  this
   GARDENER application.


        Finally,  thanks for the info regarding the InterNet. I shall need a
   few  weeks  to  study  your answer and absorb it. I am so green that I am
   confused  by all the jargon. However, what is obvious is that I will need
   to  buy a hard disk, so that in itself will keep me busy while I find the
   best  one  to buy and become familiar with hard disk management - backup,
   defragmenting etc.

        The  ATARI  Computing  mag  is  running a lot of feature articles on
   comms so I have a lot to read up on there. On the other hand I am rapidly
   coming to the realisation that perhaps I will not spend any more on ATARI
   peripheral  and  save  my  money  instead  to  buy  a PC. I shall however
   probably wait until the new century then I won't have a millenium problem
   and the price of MMX technology will have dropped.

        I  have  taken up Raymond Reid's kind offer to test my program, so I
   won't send you the updated version.


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

   To:      Louis Maule-Cole
   From:    Giles Greenway

        I'm  glad  to  hear  you're getting help with your gardening program
   -good  luck. There's nothing wrong with your program loading Degas format
   backgrounds,  but  new  software  written for the ST comes with some very
   sophisticated interfaces these days. The Degas format assumes you must be
   using  one  of the standard ST high, medium or low resolutions. There are
   plenty  of  standard  STs  still  out  there,  but  your program could be
   launched  on  a TT, a Falcon, a Macintosh equiped with MagicMac or even a
   Silicon  Graphics  workstation  running  the  STonX  emulator  !  Drawing
   directly on the Desktop can be a bad idea too. Almost all new programs do
   everything   in   a  proper  GEM  window  as  multi-tasking  is  becoming
   increasingly  common.  Somebody,  somwhere,  basking  in  front  of their
   68060-powered  Hades  will  want to start a three-hour ray-tracing job in
   the background, and then run your program to sort out the garden... We're
   all  still  learning, so write your program any way you want. The two GEM
   programs  I've put on the last two disks both multi-task happily when run
   under  MiNT,  but they're still pretty spartan. I can sort out your Degas
   question, though. The format of the "header" (much more civilised to call
   it a pre-amble, ignore the jargon) is as follows:

        The  first  two bytes are interpreted as a word, and give the screen
   resolution  to  be used, 0 is for low-res .PI1 files, 1 is for medium res
   .PI2  files,  and 2 is for high res pictures with the extension .PI3. The
   screen  sizes  are 320 by 200, 640 by 200 and 640 by 400 respectively. As
   you can see, there is no scope for images larger or smaller than standard
   ST screens. The next 32 bytes, or 16 words, represent the colour palette,
   and  hold  the  RGB (red, green and blue) values, each value is given one
   "nibble", or four bytes:


                            0000  0000  0000  0000
                                  RED   GREEN BLUE

        Finally,  the next 32000 bytes hold the picture data. .PC? files are
   compressed,  and  so are a bit more complex. If you want a picture format
   that's  flexible, portable and has a useful degree of compression without
   being too hard to implement, I'd recommened .IMG format.

        I'm sorry if my spiel about the InterNet was a little jargon-ridden.
   Which  bits  are causing the trouble ? I hope everyone feels free to chip
   in  and  explain things a little better. I'd advise trying to get on-line
   if you can, -it's fun. The RSVE modification I mentioned has come down in
   price, and now Titan Designs are selling fast 33.6 modems for less than I
   paid  for  my  28.8 ! A modem can always be taken with you if you want to
   move  on  to the PC platform, but I'm not sure if that's a good idea. I'm
   seriously  considering shelling out for a Falcon Mark X, to which I might

   fit  the  AfterBurner  modification  at  a  later date. If I have a maths
   co-procsessor  fitted  that the machine could make a very reasonable stab
   at  running  Linux.  The Hades and Direct060 TT clones might have Pentium
   cards,  but then if I wanted a Pentium... The best hard drives to get are
   probably  the  MiniS  drives  from Systems Solutions. You can get a 270Mb
   drive  complete with the ICD Link2 adapter for about two hundreed pounds.
   The only reasons I stick to the Atari Platform are that it's easy and fun
   to  use.  There's  a  thread  on  comp.sys.atari.st where most people who
   bought PCs say they're glad they held on to their STs. With enough memory
   (2Mb  to  be  comfortable)  you  can  access  the two main staples of the
   InterNet,  mail and news, for which I use the Oasis2 package. If you want
   to access the Web using one of the packages I mentioned last month, youll
   need a good screen resolution, at least ST high-res.


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

   To:      Giles Greenway
   From:    Jason J Railton
   Re:      KillThings Demo

        I  must  admit  that  I  was  impressed  by the KillThings Demo. The
   texture  mapping  was  surprisingly  quick.  My only reservation with the
   display  is that you can't see very far ahead, which makes movement a bit
   frustrating. Also there's an occaisional problem with walls being clipped
   near  the  edges  of  the  screen.   I'd suggest you could bring the side
   borders  in  a  little,  or add a status bar to reduce the overall screen
   area and give you the extra time to draw further into the screen.

        Perhaps  if  the  programmers  had spent more time on the game and a
   little  less  time on the fake Windows95 map editor, it would be finished
   by now.

        Still,  best  of luck to you if you're going to work on it. It could
   be  pretty  good. How much more work does it need ? I haven't had time to
   go over the ZIPped files myself.


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

   To:      Jason J Railton
   From:    Giles Greenway
   Re:      KillThings Demo

        I'm  not  an  assembly programmer (yet) so I won't be working on the
   game ! We really aren't short of Doom clones on the ST are we ! I shelled
   out  for  Destruction  Immenent last month, and I was very impressed. Did
   you  read  the  review in Atari Computing ? I think the points made about
   the  creature graphics were fair. The "evil non-material beings" are just
   cartoon  ghosts  straight  out  of  Scooby Doo ! The game needs all eight
   grey-scales  in low-resolurion to draw the rooms and tunnels, but then so
   did  Dungeon  Master,  and  it's creatures were quite scary. I'm sure the
   authors  wanted  to  avoid the blood-and-guts aspects of Doom to make the
   game  more  suitable for kids, (or more suitable for parents, the "little
   darlings"  seem  to  love  the  sight  of  blood...)  but  slightly  more
   threatening  monsters  could  have  given a more edgy feel. As it is, the
   pace of the game is just right, and it can even create some real tension.
   Perhaps  the  ConXtions  disk-zine  announced  in the last issue can help
   supply programmers with a better class of monsters...


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

   To:     Everyone
   From:   Jason J Railton
   Re:     Sierpinski Triangle

        I've sent in my machine code fractal triangle program, but as I said
   last  month  I  accidentally  saved  over  the  source code ! I'll try to
   develop  a  better  one. You can see this one zooms, but since I can only
   add  lines  every  2^n lines of the original triangle, I'm limited in how
   precisely  I  can  control  the zoom. This is why the zoom accelerates so
   rapidly.


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

   To:     Everyone
   From:   Jason J Railton
   Re:     Other stuff

        I've  sent  in  a  parallax  scrolling demo, and I'm nearly ready to
   release  my  puzzle  game  BUZZSAW.  I'm  just fine-tuning the difficulty
   levels now.

        I'd  like  to know if this parallax scrolling demo works on half-meg
   STs.  It  uses a lot of pre-shifted data for the scenery, and I'd like to
   know  if it fits in 512k. I've also developed the parallax scrolling into
   block-built scenery, possibly for a platform-type game.

        As  for  my  3D  maze  game, the next step is to devise a method for
   storing the scaling sprites and adding them into the game.


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

   To:      Jason J Railton
   From:    Giles Greenway
   Re:      Parallax Scrolling

        Jason,  your  scrolling  demo  worked fine on my old 520ST. I ran it
   from  the Desktop, so you've probably got around 200Kb to spare. It looks
   great, I can't wait to see the finished products !


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

