

    ICTARI USER GROUP             ISSUE #10                       May 1994

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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
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                              INDEX FOR ISSUE 10
                              ==================

    FOLDER                          SUBJECT
                              
    ASSEMBLY       Complete set of floating point arithmetic routines.
                   Routine to read command line text string.
                   The event_multi 'right button' problem solved at last.
                   Twist scroll program, updated version.

    C              Boink, a Break-out type game with source code.
                   The event_multi 'right button' problem solved at last.

    GFA            Code to read command line on TTP programs.
                   GEM Window handling routines.
                   Colour scroller routines.
                   Corrections to bit maps article (see issue 8).

    PASCAL         Pipe monitor. Displays AES messages.

    STOS           Moving block puzzle game.

    MISC           Atari Explorer Online Programmers Journal  Issue 2.
                   Various GEM bugs discussed.
                   Program to display active GEM/TOS/BIOS/AES/VDI  calls.
                   The LZW and GIF compression algorithms explained.
                   Membership list.
                   Index for issues 1-9.

    In next months issue of ICTARI (this may change) :-

    ASSEMBLY       Conversion of number to binary string.
                   Conversion of number to hex string.
                   Binary to decimal conversion routine.
                   Decimal to binary conversion routine.
                   Routine to input hex number from keyboard.
                   Chip music playing routines.
                   Auto folder time set routine.

    C              GEM Tutorial by J White.  Part 1. Introduction.
                   Porting IBM PC RSC/Doodle to Atari GEM.
                   Floating dialogue library for Lattice C.

    GFA            Circles and spheres code.
                   Picture image cutter and saver program.

    PASCAL         Program to display boolean expressions as a Karno map.

    STOS           Number guessing game that talks to you.

    MISC           Blitter Chip manual.
                   Click anywhere title box using Resource File editor.

    For future issues :-

    Polyline drawing routines in machine code.
    Bezier curve drawing routines.
    Picture decompression routines for IMG, Degas, Tiny, PCX, PAC, etc.
    Picture compression routine for IMG pictures.
    HP DeskJet/LaserJet compression routines (Mode 2 TIFF).
    Using the Xbtimer chip.
    Tutorial for using GEM commands from machine code and C.
    Playing sound samples on non STE machines.
    Picture switching techniques.
    VBL queue information.
    Printer driver code for printing mono/colour images.
    Sprite tutorial and code.
    Complete GFA Basic manual.

    -----------------------------------------------------------------------
                                   EDITORIAL
                                   
    MEMBERSHIP
    
    As a result of  our  adverts  in  MicroMart  magazine  we  have had ten
    enquiries and 4 new  members  so  far.  Please  send  in more MicroMart
    advert pages to us if you don't  need  them.  We have also had four new
    members as a result of other letters sent to various User Groups and we
    would like to welcome them. ST Format  have mentioned the group in this
    months issue of the magazine  which  may  bring  in more members. Total
    membership (excluding the committee) is now 33 members.

    We don't like to  keep  nagging  but  were  are  going to anyway. Would
    members who prefer to send  us  a  disk  each  month PLEASE return them
    BEFORE the 10th of next month otherwise it entails a lot of work for us
    in the few days before publication on the 17th. If you decide to cancel
    your membership (heaven forbid) we would appreciate it if you would let
    us know so that we don't waste time  and phone calls trying to find out
    what you want. Also, if  you  do  send  in  a  disk, please put a short
    letter on it for the correspondence  section,  just  a note on what you
    would like to see, not like  to  see, programming problem, etc, etc. If
    we don't get ANY feedback we might  feel that we are not providing what
    members want. Also  we  still  need  programming  articles or routines,
    especially in C, GFA and STOS so  if  you have anything which may be of
    interest to other members, please send it in to us. You can always ring
    us first on the number above if you  are  not sure if it will be of use
    or if it has been done before.

    LZW GIF Compression
    
    On this disk is  a  useful  document  file  explaining  the LZW and GIF
    compression formats. Unfortunately, as far  as  we are concerned, it is
    written in a foreign language, double dutch. Would anybody care to have
    a go at writing some  code  which  can  convert  files  from or to this
    format for general use.

    DOCUMENTATION
    
    We are planning a number of tutorial type articles for future issues in
    which diagrams could be used to  explain various points. Obviously with
    a pure ASCII text  file  it  is  very  difficult  to  draw a diagram or
    display a picture and trying to  use  just the ASCII line characters is
    not very  satisfactory.  We  would,  therefore,  like  to  explore  the
    possibility of incorporating images in these document files.

    There are two main alternatives :-

    1. Use a pure ASCII format for  the  text  as we do now and provide any
    pictures as .IMG files separately so  that  the  reader can make up his
    own printed document using whatever Word-processor/DTP program he uses.

    2. Publish the  article  in  a  Word-processor  format  which can store
    images and which all members can  use. Possible programs would be First
    Word Plus, Write-On, Thats-Write, Redacteur  and Calligrapher. Of these
    we would think Calligrapher would be  favourite since it was given away
    free on  the  Atari  ST  Review  cover  disk  (Issue  24)  and  should,
    therefore, be available to most members.  One problem with this program
    is that the printing is abysmally slow, even on our Laser printer.

    Would all members please let us know when they send their disk back for
    next months issue or if you  have  already  paid for next month perhaps
    you would drop us a postcard or  ring  us.  If we don't get a unanimous
    decision on any Word-processor we will probably go for option 1.

    Incidentally if you send in a text  file and you have access to Protext
    it would help us if you could send  it  to us in Protext format. If you
    don't have Protext then you can  send  it  in ASCII format as usual. We
    try, where possible, to  format  text  files  with  a  4 character left
    margin (so that the print-outs  can  be  stored in ring binders without
    making holes in the text) and with  the  right margin set to 75 so that
    text editors that have a scroll bar on the right side of the screen can
    still show the whole line.

    TWIST SCROLL PROGRAM
    
    In issue 9 we provided a Twist  Scroll program (in M/C) which failed to
    work on  machines with more than 1Mb  of memory and Ian Hancock (alone)
    kindly fixed it to work  properly.  We  have  included it again in case
    anyone would like to use it and, perhaps, to improve it still further.
    -----------------------------------------------------------------------
                                CORRESPONDENCE
                                
    To *.*
    From Peter Hibbs

    Does anyone have any information on writing CPX accessory programs (for
    XCONTROL) in machine code. There  were  a  number published on a recent
    cover disk which were quite useful but  some were in German and I think
    it  would  be  useful  to  write   some  additional  ones.  The  'Atari
    Compendium' book does have a shell CPX  program  but  it is all in C, a
    machine code version of this would be handy, if it is possible.
    -----------------------------------------------------------------------
    To *.*
    From Ian Hancock [morf]

    QUESTION: Is anyone interested  in  a  program  which converts spectrum
    emulator SNAP (SNA) files back  into  sound  signals for recording onto
    tape. These can then be loaded  back  into  the spectrum !!! If you are
    let ICTARI know and I'll send  in  the  code  -  Oh yeah it's STE ONLY.
    Currently it won't convert snaps which use  IM 2 on the speccy. I don't
    know why at the moment either :  By  the  way the code is VERY untidy -
    I'm pretty ashamed of it. Just wondered ?
    -----------------------------------------------------------------------
    To *.*
    From Steve Gale

    I am writing a simple text editor  in  machine code (Hi Rez) which uses
    the normal mouse arrow cursor AND  the VT52 flashing block text cursor.
    The problem is that whenever the  mouse  cursor  is moved over the text
    cursor the text cursor block gets corrupted until it is moved. Is there
    any way of avoiding this or will I have to write my own cursor flashing
    routine and if so how.
    -----------------------------------------------------------------------
    To ICTARI
    From Kevin Preece

    Have you considered  advertising  in  ST  Applications,  a magazine for
    serious users, published by the ST Club.

    */ We have sent STA details of ICTARI and they have promised to publish
    a full page article about the group sometime. ICTARI /*
    -----------------------------------------------------------------------
    To *.*
    From Dick Teuber

    I would like to write a program which  uses a Resource File but I don't
    want it as a  separate  file  on  the  disk.  Does  anyone  know how to
    incorporate the .RSC file within a program in C or machine code.
    -----------------------------------------------------------------------
    TO: Nick Bates
    FROM: Ian Baker

    > Everyone  wants  to   make   sure   their   programs  are  compatible
    with other  machines and  all  TOS  versions,   does  anyone  have  any
    general rules to follow in order to ensure compatibility - particularly
    with the Falcon ?

    Your program should either be a full  GEM application or use text only,
    otherwise it will not work with MultiTOS.

    Get the screen size from the VDI,  do  not assume it is a standard size
    and do not use Getrez().

    Our Family  Tree  program  worked  unchanged  on  the  Falcon  and with
    SpeedoGDOS. It needed a change for  MultiTOS  due to a silly mistake in
    programming, when  -1  was  passed  instead  of  1.  Standard  TOS only
    recognised 0 and not  0,  whereas  -1  meant  something  to MultiTOS, a
    function extension we did not mean to call.  Check  parameters  to  O/S
    calls.

    Generally the compatibility is excellent.

    TO: All
    FROM: Mark Baker

    The  article  on   Pexec   was   interesting,   but  incomplete.  Under
    MiNT/MultiTOS  six more modes were added.

    Modes 100, 104 and 106 work  like  modes  0,  4 and 6 respectively, but
    asynchronously (ie. multitasking). I can't remember now how you get the
    child's return value since obviously Pexec returns before the child
    finishes.

    Modes 200, 204 and 206 work like modes  0, 4 and 6 respectively but are
    for overlays, they remove your program from memory and run the new one.
    Therefore they never return.

    However if you intend to write programs for MultiTOS the shel_write AES
    call has been extended - it  now  works  for  one  thing - and launches
    programs correctly, with TOS programs  under  miniwin or toswin and GEM
    programs running as if launched from the desktop.

    */ Thanks for the update, if  anyone  has more info on writing programs
    that are compatible  with  the  modern  Operating  Systems  we would be
    pleased to hear about them.  ICTARI /*
    -----------------------------------------------------------------------
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