Demo Construction Kit

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Introduction

The Demo Construction Kit is a logical way of creating animated demos including cool graphics. It allows full integration of music,text and images in the demonstrations. It functions on all the Atari computers and compatible ST's, i.e STF, STFM, STE, MEGA-STF, MEGA-STE and can be installed on your hard drive if you wish.

You have three discs:

The first disk includes the program as well as a few demos in .prg (can be used directly at the office) and in DCK (file to be loaded under the program). here is the list of files:

  • DCK.PRG.
  • DCK1.JNX.
  • DCK2.JNX.
  • DCK3.JNX.
  • DCK4.JNX.

The second disk includes the following files:

  • DESSINS (Designs) including the background pictures.
  • FONTES (FONTS) including the characters.
  • SPRITES including the sprites.
  • RASTERS including the rasters.
  • TRAJ SPRITE including the trajectories of the sprites in .DAT.
  • TRAJ SCROLL including the trajectories of the scrollers in .TRJ.

The third disc includes the following files:

  • DIGIT.STE (DATA STE) including the digital music for the STE.
  • DIGIT.STF (DATA STF) including the digital music for the STF.
  • MUSIC CHIP including the music for the sound chip (any ST).
  • SOUNDTRACK including the soundtrack music.

This program has been conceived entirely on a 68000 to ensure speed of execution and fluency and all this by a Frenchman in French(well it was till I translated it). All the functions of execution of demos such as scrolls, borders, sprites, music, rasters, stars, equalizers, etc. Have been put together in one program only to make it more economical and efficient.

General

Use of the DCK

The DCK uses the Ataris GEM interface. It is therefore controlled entirely by the mouse. This system allows speed and ease of use. The main screen of DCK is separated into 2 parts:

  • The rolling menus
  • The selection icons

The rolling menus are represented by a menu bar which is at the top of the screen. Each name on the menu bar hides several options. If you point at a name on the menu bar with the mouse(god man this is really basic tuition), a gathered sub option appears, you must then bring the mouse down to the sub option required(the one pointed at by the mouse, darkens) and click on it. In some cases the rolling menus are used to define whether an option has been selected or not. In this case if a sub option has been selected, a kind of v is displayed on its left.

The icons are represented by drawings on which you must click. On the main screen of the DCK there are 10 situated at the bottom. They are accompanied by a word describing their function. These are: scroll, text, deformation, sprites, block copiers, stars, borders, color, music and utilization.

There is a third kind of object used in the DCK. These are dialog boxes. You have access to these boxes using icons or rolling menus. Each animation has all its parameters gathered in a box. A box is usually represented by a large white square edged with a black line in which there is:

  • at the top: text describing the box's function.
  • at the bottom: an OK switch enabling you to get out of the box when all the parameters are adjusted.


Within the boxes, parameters can be modified in several ways:

  • If the parameter can only be true or false (select or de-select) it is often represented by a button. This button is a text edged with a black background if the parameter is selected and a white background if it is not.
  • If the parameter can take a multitude of values, it is often represented by two arrows on each side of the corresponding numbers(either top/bottom or right/left). All you need to do is click on the arrows to increase or decrease the value of the parameter.


The system of coordinates

In most animations, you must tell the computer where in the drawing you want to animate is or display it on the screen. This indication is made with the use of two coordinates (usually represented by x and y). These two coordinates are measured in pixels. You must therefore know that the demos generated with DCK are in low resolution therefore the dimensions of the screen are 320 pixels wide and 200 pixels high. You must not forget either that the corner of coordinates x=0, y=0 is the top left corner and that the more right you go, the more x increases and, the lower you go, the more y increases.

Example: 

TOP RIGHT CORNER: X=139,Y=0(320 PIXELS FROM 0 TO 319).
BOTTOM LEFT CORNER: X=0,Y=199.
BOTTOM RIGHT CORNER: X=319,Y=199.
MIDDLE OF THE SCREEN: X=159,Y=99.

Dealing with colours and plans

The demonstrations done with the DCK function in base resolution. This mode enables the 16 colors to be displayed simultaneously on the screen without using any tricks(and even more with the rasters). These are chosen from a pallet of 512 colors for the Atari STF or from a pallet of 4096 colors for the STE, MEGA STE and TT. In fact, the computer disposes of 16 slots to put the colors that you want. These slots are numbered from 0 to 15(which makes 16 possible colors).

Example of color: 

     -700:THE  COMPONENT  OF  RED IS A7 AND  THE  OTHERS  AO.THIS 
      COLOUR REPRESENTS RED.
     -070:GREEN.
     -007:BLUE.
     -000:ALL THE COMPONENTS ARE AO.IT IS THEREFORE BLACK.
     -770:A MIXTURE OF RED AND GREEN GIVES YELLOW.
     -077:BLUE-GREEN.
     -707:PURPLE.
     -777:THE MIXTURE OF ALL COLOURS GIVES WHITE.
     -333:LESS  WHITE  THAN WHITE,IT  IS.......NO,NO  A  WASHING 
      POWDER IS GREY.
     -ETC...
     -PUB:THE WHITE,WHITER THAN WHITE ON STE,IT IS FFF.

Lets now approach the thorny subject of plans. You now know that you have 16 colors simultaneously available on screen. The Atari has 4 plans in low resolution. What is a plan and why 4 of them?

First, you must have mastered what we saw previously otherwise, what follows will seem very complex.

First, lets go through the color numbers(not the components but the place numbers from 0 to 15) in binaries (or base 2). 

     COLOUR 0:0000  COLOUR 8:1000
     COLOUR 1:0001  COLOUR 9:1001
     COLOUR 2:0010  COLOUR 10:1010
     COLOUR 3:0011  COLOUR 11:1011
     COLOUR 4:0100  COLOUR 12:1100
     COLOUR 5:0101  COLOUR 13:1101
     COLOUR 6:0110  COLOUR 14:1110
     COLOUR 7:0111  COLOUR 15:1111

From this conversion, can be determined which plans use the color in question. You notice that the color numbers are coded on 4 bits ( 4 binary numbers ). These bits corresponds to plan 1 ( if this bit is a1, the color uses plan 1, otherwise it does not use it ). The 2nd to the right corresponds to plan 2, then the others correspond successively to plans 3 and 4.

Example:

Lets examine colour 5: the conversion of 5 in base 2, gives 0101. The colour 5 uses therefore plans 1 and 3.

The colour 1 uses only plan 1 ( since 1=0001 ).

The colour 0 uses no plan since 0=0000. The colour 0 is therefore the background colour. If for example, you put 700 in the slot of the colour no 0, the background will be red.

Small bit of advice: reread these explanations several times until you are sure you have fully mastered the plans and the colours since these facts are needed to make a good demo.

A good demo is fluid. That is to say that the animations are not jagged. For this, the entire demo must not exceed 1/50 tme per second. If these are jaggered, then there are to many animations on screen at the same time. You must therefore get rid of some. to see the time used, you need to press on one or two of the shift keys during the demo. You will see that the background colour changes in one place on the screen. The lower this change takes place, the closer the time is to 50th of a second and therefore the less time you have left.

The following is a summing up chart of the plans used by each colour ( keep it handy ). 

___________________________________________
:NUMBER:BINARY:PLAN 1:PLAN 2:PLAN 3:PLAN 4:
-------------------------------------------
: 00   : 0000 :  NO  :  NO  :  NO  :  NO  :
-------------------------------------------
: 01   : 0001 :  YES :  NO  :  NO  :  NO  :
-------------------------------------------
: 02   : 0010 :  NO  :  YES :  NO  :  NO  :
-------------------------------------------
: 03   : 0011 :  YES :  YES :  NO  :  NO  :
-------------------------------------------
: 04   : 0100 :  NO  :  NO  :  YES :  NO  :
-------------------------------------------
: 05   : 0101 :  YES :  NO  :  YES :  NO  :
-------------------------------------------
: 06   : 0110 :  NO  :  YES :  YES :  NO  :
-------------------------------------------
: 07   : 0111 :  YES :  YES :  YES :  NO  :
-------------------------------------------
: 08   : 1000 :  NO  :  NO  :  NO  :  YES :
-------------------------------------------
: 09   : 1001 :  YES :  NO  :  NO  :  YES :
-------------------------------------------
: 10   : 1010 :  NO  :  YES :  NO  :  YES :
-------------------------------------------
: 11   : 1011 :  YES :  YES :  NO  :  YES :
-------------------------------------------
: 12   : 1100 :  NO  :  NO  :  YES :  YES :
-------------------------------------------
: 13   : 1101 :  YES :  NO  :  YES :  YES :
-------------------------------------------
: 14   : 1110 :  NO  :  YES :  YES :  YES :
-------------------------------------------
: 15   : 1111 :  YES :  YES :  YES :  YES :
-------------------------------------------

The good use of plans enables you to get a huge proportion of unusual effects amongst which the transport scrolling effects, the superimposition of objects or scrollings. If you master the system of using plans, you can save time on animations and therefore you can do more at the same time.

How to save time

Let us, for example do a scrolling on the 4 plans without bothering about the colour used by the scrolling but this method uses a lot of time. The method using the least amount of time consists in choosing the colour used so as to scroll only on the minimum number of plans. In the case of a scrolling in one colour one, you can manage to use only one plan.

Possibilities: 

SCROLL ON PLAN 1=> FONTS ON COLOUR 1(0001).
SCROLL ON PLAN 2=> FONTS ON COLOUR 2(0010).
SCROLL ON PLAN 3=> FONTS ON COLOUR 3(0100).
SCROLL ON PLAN 4=> FONTS ON COLOUR 4(1000).

Notice: It is impractical to always save the fonts in one colour on colour no 15 since it uses all the plans (15=1111 in binary) and you can therefore choose an which plan you want to do the scrolling.

Careful: If for example you do a scrolling on plan 1 using a font which is on colour 15, since only one plan is used, the colour of the scrolling will be colour no 1.

Equally, you can use 3 colours with 2 plans ) e.g: colours 1, 2 & 3, use only plans 1&2) 7 colours with 3 plans and the 16 colours with 4 plans.

Lets imagine, now that we want to pass two scrollings, one on top of the other (e.g: a horizon and a vertical which cross). If you declare two settings on 4 plans, they will erase each other. the only way to get them on top of each other, is to make them use different plans and to choose and manage the colours carefully.

Example: lets pass a scrolling on plan 1 on top of a scrolling on plan 2. 

THE SCROLLING ON PLAN 1 USES THE COLOUR 1(CAR 0001=1).
THE SCROLLING ON PLAN 2 USES THE COLOUR 2(CAR 0010=2).

When the scrolling plan 1 passes at the same place on the screen over the scrolling plan 2, you get the combination 0011 which corresponds to the colour 3 that you will determine which scroll goes on top of the other.

Lets take for example a scroll plan 1 green (colour no1) and a scroll plan 2 blue (colour no2). If you want to pass the scroll plan 1 on the scroll plan 2, you will put colour 3 to be green(since colour 3 corresponds to the colour displayed at the place where there is a superimposition from plan 1 and from plan 2). The same way, you will put green if you want the scroll from plan 2 to go over scroll plan 1.


The question of pictures

The system of buffers

All the drawings used by the demo construction kit are in degas format (extension, PI1 or PC1) or neochrome format (extension .NEO), to make animations, the computer must have the drawings in its memory. For this, it has 3 slots where the picture files can be loaded. These slots are called buffers and are differentiated by one number (buffer 1, 2 or 3). When you load a picture, you will be asked in which buffer you want to store it.

Example: If you want to load a font in buffer 2, you will need to indicate in the box of scrolling using it, that the font is in buffer 2.

The operations on the pictures are kept together in the menu rolling under the name "background images".

Let us now examine the sub options available under images.

Load Picture (Charger Image)

This option enables, as its name indicates, you to load an image in the image buffers. You first need to indicate the buffer in which you want the picture to be loaded then, all you need to do is click on the picture file chosen (neo, pi1 or pc1).


Save Picture (Sauver image)

This option enables you to save a picture contained in a buffer. Images can only be saved in degas formats PI1 and PC1. PC1 saves on disc space and is in actual fact a compacted degas picture.

Visualize picture (Visualize Image)

This option enables you to see the pictures contained in the different buffers. First the number of the buffer in question is asked. Then you must indicate which colours of the picture you want to see on the demo (sorry this is the best translation that I could do with this particular phrase).

Erase Picture (Efface Image)

This option enables you either to empty the buffer of your choice.

Copy the Picture (Copie Image)


This option enables you to copy one full picture from one buffer to another, or to copy plan by plan. A buffer to another. The menu background picture enables you to define which picture is on the poster during the animations. If you don't want any background picture, all you need to do is validate (click).

Keep your reference

To keep your demonstrations, you must save on to the disc before stopping the computer. You must put a disc (not write protected) into the disc drive. Make sure that there is enough space left on the disk. then when you are ready go to the filing menu and click on the sub option "save demo"(sauver demo).

NOTE: to easily recognize a file stored with the DCK, it is best if you get into the habit of always putting the same extension (.dck).

Later on you will be able to load your demo with the option "Load Demo"(Charger Demo).

If after finishing your demo, you want to store it in the form of a program which can be executed under the desk, you must click on the option "compile demo". You will have to give the name of your program and end it in .prg(extension.prg). You will then be asked to insert the disk DCK (disk 1). The demos stored with the DCK are automatically compacted to save space on the disk. You will however, need to enter the power of compacting (the higher the power, the longer the compacting will take).

The waiting times are roughly as follows: 

     Weak power -> 20 seconds
     Average power -> 2 minutes
     High power -> 20 minutes

Careful: Do not forget to save your demo to disc before compiling otherwise the memory will be entirely erased.

Execution of your Demo

To execute your demo and to see the animations that you have generated, all you need do is click on the icon visu. To remove the demo from the screen and return to the editor, press on the space bar.

Explanation of the screen

The Colour Box(Couleur)

This box will enable you to make all the necessary colour adjustments during your demo. Click on the colour icon (couleur) or press the F8 key. The main box of selection of the colour menu appears.

To see the picture without any other effect, you must first load your picture in buffer 1 and position the background picture on this buffer, then you must position yourself on the selection (palette) n000 then, select colours from buffer 1. (since your picture is located in buffer 1).

You come out of the colour box and check while doing the demo that your picture is truly seen with the colours of buffer 1. However, if you select colours from buffer 2 in the colour box, you can notice that the colours displayed become black (if no picture has been loaded in this buffer). Now if you look at your screen, you will see a black screen since the colours have all turned to black.

Now, in the same way as before, load another picture in the buffer 2, then in the colour box, select colours from buffer 2. The colours displayed are those of buffer 2.

When you do the demo, you now see the picture which is in buffer 1 with the palette of the picture contained in buffer 2.

You have 3 buffers which can be used in the same way plus a 4th buffer which will be studied later on.

You can manually modify the colours.

For this, under the colour menu, you can choose the colour you want to change by clicking on one of the arrows right or left of the parameter number situated left of your screen. You will notice that the black cursor goes automatically on the corresponding colour. The value of this colour is indicated in the parameter r.g.b. To change the value of this colour, change the value of this parameter with the arrows (up & down). The colour changes automatically. You can, for example, position yourself on colour 00, then put fff as the value and look at the picture, you will notice that the background has become white (the value of $fff corresponds to white).

You can do the same thing for each colour number.

You have the possibility:

  • to define 275 different palettes
  • to change them with the load or save option or even erase them with the erase option.

To carry on, put the background picture on none.

With the colour menu, click on rasters.

Load, with the option load, a whole lot of colours for your rasters. The extension of the files is .hbl. You will display your rasters in the same way as for palettes,the principle for modification is the same as the one for the palettes but with the box situated on the right hand side of your colour box. You also have 274 different rasters at your disposal.

First we are going to explain how to use them as simply as possible.

Place the parameter interval on 001 by clicking on the right/left arrows and the parameter on coul (colour) on 00 then come out of the colour box. Go to the 1st menu validation and validate the rasters option (a sign appears on the left to indicate that this option is activated during your demo).

Have a look at your demo: you should see colour strips on your screen, these strips are called rasters or hbl. The colours of these rasters are those that you loaded under the colour box heading.

Return to the colour box the modify the parameter of the interval and put it to 010. Do your demo again, you will notice that your colour strips are wider. The interval therefore corresponds to the thickness of your colour stripes. Now, put the coul parameter on 02 and have a look: you will notice that the colour stripes have disappeared, this is normal since your colour stripes are only visible on colour 02 and since you have not loaded a picture, the colour 02 is not used (only the colour 00 is used for an empty picture and which corresponds to the background). Now cancel the rasters parameter on the unrolling menu,then load on a picture and do all the necessary operations to see it in the demo mode with it's correct colour palette.

After this, while still in the colour box go to the rasters mode, place the interval on 001 and erase the rasters then place yourself on number 100 and validate the PAL parameter. Then go to palette mode. If you have completed the operations correctly, you will have the palette of your picture in palette no: 000. Go to palette no: 001 and modify it manually (put the colours that you want!).

Have a look at your demo: you should see your picture with the palette and without any other effect.

Go back and validate the rasters in the pull down menu and look at your demo once again: you will notice that in the middle of the screen (100th line) the palette changes and corresponds to the palette no: 001 that you have put in.

We can therefore see that the parameter PAL modifies the palette of the given raster, you can of course change the palette of your demo as many times as there are palettes (274 palettes available). At each request for alteration, you display the following: for e.g, indicate a change of palette at raster no: 150 by placing yourself on number 150 and by validating the pal parameter. Then place yourself in palette mode on the palette no: 002 then put colours on it. Have a look at your demo: you will notice a change of palette at line 100 with palette no: 001 and a change of palette at line 150 with palette no: 002.

Return to the colour box, then cancel the following two palettes on rasters no: 100 and 150. Now select the "cycle" option(cyclage) and put the parameter (n.b palette on 001) then put a pal (suivaute) on raster no:000.

Look at your demo: you will see a cycle of colours; this cycle uses palettes 001 and 002 in that order.

Now select the PAL parameter. Suivaute of raster no: 000 and place a PAL suivaute on raster no: 100.

Look at your demo:

You can notice that the change of palette only occurs from raster no:100 always with the palette 001 and 002. In fact, the cycle of palette starts at the 1st raster where the pal parameter suivaute is positioned. This cycle can use all the palettes available except palette no: 000.

The Scrolls

You can define 10 different scrollings. To activate them, you need to select them in the validation menu. The 10 scrollings are noted down as scroll 0 to scroll 9.

Click on the scroll icon or press on the F1 key to gain access to the box. You must specify which scroll number you want to edit:

To do this, click on the corresponding number. You then have access to the scroll parameter box.

You must have loaded a picture beforehand containing the objects that you want to scroll (blending of characters decor or other) in one of the three buffers.

You must specify in which buffer the objects to be used are, by clicking on the corresponding numbers 1, 2 or 3.

Then you must specify the size of your objects to be scrolled with the parameters of the letter box (lettres).

  • HEIGHT(HAUTEUR): defines the height of your objects in no of lines.
  • WIDTH(LARGEUR): defines the width of your objects in no:of pixels.
  • STARTING LINE(LIGNE DE DEPART): is the line where your first object is in the buffer (this enables you to put several kind of objects in the same buffer).

You must note that for one same scroll, your objects always have the same dimensions.

You must define the order of your objects in the buffer, for this, use the parameters found in the order box(ordre), since each object is associated with a precise letter which will enable you to select it later on.

You can use the ascii order by clicking on it or defining the order yourself by clicking on other (autre): at that point, a box appears and you must give the corresponding sign for your objects. (the 1st sign defines the 1st object and so on). Here is a list of the acceptable signs:

!"#$%&'()*+,-./0123456789:;<=>?.

ABCDEFGHIJKLMNOPQRSTUVWXYZ

As well as a space (difficult to show on a list).

To check that you have entered the dimensions of your and order of your objects correctly, click on the option "see"(voir) you can then see your object buffer-moreover, a square surrounds an object; to check that the order that you have given is correct, use the keyboard to go to the corresponding objects (press escape to exit).

You can also activate/de-activate the plans of your objects by using F1 to F4.

You need to specify on which plans the objects are by activating/releasing the corresponding plan parameters.

You must define the trajectories of your scroll.

There are 3 types of routes (trajectories)possible:

  • Vertical(Verticale)
  • Horizontal(Horizontale)
  • Parametable(Pparametrable)

Each trajectory will be created, stored or loaded with corresponding options. Click on the created (cree) option: You reach the options page of your trajectories, to select the type of trajectory, press on:

  • HELP : PARAMETABLE TRAJECTORY
  • INSERT : HORIZONTAL TRAJECTORY
  • UNDO : VERTICAL TRAJECTORY

Then to define the place of your trajectory on the screen, use the mouse.

Horizontal Trajectory

After having pressed on insert, at the top of the screen are written:

-THE START COLUMN (COLONNE DE DEBUT) -THE BEGINNING LINE (LIGNE DE DEBUT) -THE END COLUMN OF YOUR TRAJECTORY (DE FIN DE VOTRE TRAJECTOIRE) -THE MODULE (MODULO)

You move your trajectory directly with the mouse:

The left button modifies the parameter for the start column (deb). The right and left buttons change the end of column parameter (fin). (1st press on the right then keeping it pressed down, click on the left).

The module parameter indicates the space between the lines of your trajectory: if the value is 1, this means you will have a normal trajectory; if it is 2, you space out by one line etc. If this parameter is negative, you will have reversed trajectory. To modify this parameter, use the keyboard (don't use the numerical board!).

-> From 0 to 9 for the value of the module. -> - For the sign of the module.

You can also define 10 different trajectories by using the digits 0 to 9 of the numerical board. The number of the trajectory in the process of editing is indicated at the bottom left of the screen. Each one of them has a code (e.g :h0,h1...) which will have to be associated to the text of the editor.

The digits + and - of the numerical keyboard enable you to change the column end of trajectory parameter.

Vertical Trajectory

Press on undo to define it. At the top of the screen, the characteristics of your trajectory are indicated.

  • COLUMN (COLONNE):Indicates beginning
  • TOP LINE (LIGNE HAUT):Indicates top line
  • BOTTOM LINE (LIGNE BAS):Indicates bottom line

The left mouse button modifies the top line and column.

The right and left button modifies the bottom line.

The + and - keys act as a more precise devise on the bottom line.

You can also have access to 10 trajectories (v0 to v9).

The cursor keys also allow you to move your trajectory more accurately.

Parametrical Trajectory

Press on help to define it. At the top of the screen, the position of each block used by your trajectory is indicated. You have 40 blocks at your disposal that you you can place on the screen independently with the mouse.

The left button of the mouse enables you to define the position of each block.

The right and left button erases the corresponding block.

The module can carry from 1 to 4, the same ways as for the horizontal screen.

The cursor keys enable you to move your trajectory more accurately.

To have access to 10 trajectories, use the keys on the numerical block (p0 to p9).

To exit from the trajectory creation press the escape key.

The decal.vert (move forward) parameter corresponds to a glocal move in number of lines of the trajectory.

The text

In order to define the succession of objects to scroll, you must define it in a text. For this, click on the text (texte) icon or press the F2 key. You must enter the number of the text which must be the same as the number of the scroll to which it is linked.

The box for editing text appears. In this box, you can load, save, edit and print a text. With the keys F1 to F8 you also have the essential functions of a word processor. The size of your text for scrolls no: 0 and 1 is 5400 units and for scrolls no: 2 to 9 is 918 units. All you need to do is type your text (using authorized keys).

To show the end of your text, use the return key: a symbol for end appears. If you don't put this sign, your text will go up to the end of the buffer.

To select the various possible curves for each text, you must use the help key: the symbol for curve selection appears. Then you must give the type of trajectory followed by its number:

  • V FOR VERTICAL TRAJECTORY
  • H FOR HORIZONTAL TRAJECTORY
  • P FOR PARAMETABLE TRAJECTORY

Numbers ranging from 0 to 9 ( it is advisable to 1st enter the number of the curve and then the type of scroll).

If for example: you want to use a scroll in parametable mode with no:8 curve,you must type x8xp.

NOTE: You can change the type of scroll or/and the number of the curve in the middle of the demo as many times as you wish.

Press the escape key to get out of text editing.

Stars

Initially put the background screen on none and cancel all the options that you had selected in the pull down menus. Then click on the star (etoileou) icon or press the F6 key to get the star box.

You can define 4 different types of stars:

  • Stars moving vertically top->bottom ( haut->bas )
  • Stars moving vertically bottom->top ( bas->haut )
  • Stars moving horizontally left->right ( gauche->droite )
  • Stars moving horizontally right->left ( droite->gauche )

To change the type of movement, you need to click on the corresponding box to blacken it.

To activate the stars, you must, on the pull down menu, activate the star option.

Then, look at your demo. the background colour is the one defined by number 00 of the palette n000. While the colour of the stars is the one defined by no:01 (if you left stars on plan 1) of palette n000; the stars move on the entire screen.

Return to the star box.

You can change the number of your stars with the number (nombre) parameter. The speed (vitesse) parameter defines the minimum speed of your stars while the delay (decalage) parameter indicates the number of speeds greater than the minimum speed; for example, position the number on 100, the speed on 01 and the delay on 03 then have a look at your demo.

You have 100 stars on the screen with 4 different speeds.

Now, if you put the speed on 00 and the delay on 00, you will get fixed stars since the speed is nil and there is no greater speed.

Up to now the stars were moving on the entire screen, you can make them move only on a precise part of the screen thanks to the clipping parameters which enable you to define the rectangle in which you want your stars displayed.

The parameters x min and y min define the top left corner of your rectangle while x max and y max define those of the bottom right hand corner.

For example:put x min at 000, y min at 000, x max at 160, y max at 100 and have a look at the demo: You should get stars in the top left quarter of your screen.

This rectangle of clipping must be a minimum of 32 by 32 pixels. You can also indicate on which plan you want to display your stars.

The copies of the blocks

To select the copy box, click on the copy (copie) icon or press the F5 key; you must then specify which copy number you want to edit (you can define 10 different copies).

You must indicate which part of the screen you want to copy. The source block box parameter determines the zone of the screen to be copied.

X1 and y1 define the top left corner of your screen to copy.

Width (largeur) defines the width of the part of screen and height (hauteur) the height in number of lines.

The module enables you to define the spacing in lines of the source block.

For example: if you wish to copy an entire part of the screen. Put module A1. However if from this part of the screen you only want to take one line or two, put module A2. The sign for module changes by clicking on it.

In the same way, you have to specify the target block which represents the part of the screen where the source block will be copied with x2 and y2 which represent the top left corner of this place and the module which works as previously.

You must also indicate on which plan the copy must be made. Then validate the corresponding copy in the validation menu to activate it during the demo.

Distortions (Deformations)

Click on the distortions icon or press the F3 key to get the corresponding box. You must define the zone of your demo screen to be distorted: for this, use the parameters defined in the block to be distorted.

X1 and y1 define the top left corner of the block to be distorted.

Width defines the width of the block. Height defines the height of the block.

You must note that the distortion only acts on what is on the screen, therefore if the block once distorted exceeds the screen, it will not come back.

To define the shape of the curve of distortion use the curve (courbe) box and alter the parameters accordingly.

Speed (vitesse(not rover))-defines the speed of the curve.

Amplitude-defines the amplitude of the curve.

These two parameters are dependant.

The parameter double-course (double-courbe) enables you to double your curve of distortion: the block will distort twice as slowly but the time taken by the distortion will be smaller.

You must then indicate on which plan the block is defined.

The sprites

Click on the sprites icon or press the F4 key to activate the sprite box.

You have the possibility to define up to 50 sprites. The parameter number enables, as its name indicates, to define the number of sprites used during the demo.

CAREFUL!!! Some parameters are general (valid for all sprites) and others can vary for each sprite.

Lets look at general parameters first.

The width parameter defines the width of the sprites. It is limited to 16 or 32 pixels but thanks to a trick, you can make sprites which can reach up to 320 pixels in width,(the picture is cut out in squares of 32 by 32 and each one of them is considered to be a sprite).

Another general parameter is the nb of plans (nb=number). The only combinations which are possible are:

  • 1 -> 1st Plan
  • 2 -> Plans 1 AND 2
  • 3 -> Plans 1,2 AND 3
  • 4 -> All Plans (Since the Atari only has 4 Plans)

These plans are consecutive and use therefore always the 1st plan.

Lets look now at the right hand side box (still within the sprite box). The option load traj (charge traj) enables us to load the trajectory of the sprites. For those who want to create new ones, it is at format x,y in mot (therefore 4 octets per co-ordinate)-for the others, small programs in GFA Basic and easily changeable are provided.

The option store traject (sauve traj) enables us to store a trajectory coming from a demo on a floppy disc.

The option see traject (voir traject) enables us to see the trajectory of a sprite and to change it.

The option create traj (creer traj) enables you to create a trajectory of a sprite with the mouse. The left button on the mouse records the position and the right hand button erases the last position taken (materialised on the screen by a dot). It is possible to enter 1250 dots to create a trajectory.

A sprite can be of 3 types.

  • The drawing chosen for the sprite appears on the screen and restores what was below when leaving its position.
  • The drawing appears in sprite but erases the sprite where it was.
  • The drawing appears in sprite but does not disappear and does not restore the picture beneath (can create effects).

What is the advantage of this kind of sprite?

The problem with type 1 is that to restore the background you must safeguard what was beneath by restoring it often before displaying the sprite again. This is a lengthy process.

Method number 2 brings with it a useful gain of time. Therefore if the sprites appear on a background without drawings or on plans not used, cancel the option restore (restauration). While you will need to activate it if the sprites appear on top of a drawing which you do not want to erase.

Method number 3 is special; indeed the sprite does not erase itself and does not restore the background. Therefore the sprites will remain displayed in the background of the screen.

If your sprites only move vertically (e.g rebound) activate the option x multiple of 16 to save time.

Lets move on to the step and staggering parameters of the curve.

The staggering is the added value in the curve for the coordinates of the following sprites.(this parameter is only used if you have a certain number of sprite >1). On the whole it corresponds to the widening gap of the sprites in the curve.

Example:

Staggering 0 -> each sprite has the same value.

Staggering 9 -> each sprite takes the co-ordinate situated 9 coordinates further than the previous sprite.

The step (pas) parameter corresponds to the speed of the sprites.

Example:

Step=1-> The first sprite will go through all of the points defined by the curve.(the position of the following being defined by staggering).

Step=10-> The first sprite will go through the points of the curve from 10 to 10.

There is a way of making several sprites follow different trajectories at the same time with these two parameters.

Example:

Make a curve alternating a coordinate with a circle and one with another. (2 circles) By defining 2 sprites, one step of 2 and a staggering of 0, sprite 1 will follow one circle and sprite 2 will follow the other.

The sprites, like the stars have a clipping. This is only top/bottom i.e the sprite will not appear outside the vertical limits given. These limits are defined with the parameters y min and y max.(designating the bottom and top limits respectively).

This is it for general parameters, lets now move on to parameters to be defined for each individual sprite.

The number parameter is the number of the sprite whose characteristics are displayed (to define sprite no:2, position this parameter on 2).

Each sprite can be different. You must therefore indicate where it is in the program.

  • The picture buffer-by clicking on the 1,2 or 3 in the type box.
  • The position of sprite x,y in the buffer.
  • The height.

The parameters add x and add y are the values added to the coordinates taken on the curve. This enables you to reposition the sprite at the desired place if the curve is not at the right place. Do not forget that these parameters are different for each sprite.

If the sprites are in restoration (restauration) mode, you must copy the drawings under the sprites somewhere in memory so that you can restore them when these sprites will change position.

This place must be in the picture buffer. You then need to leave a small place in one of the pictures used and declare its position with pos x, pos y and buffer for each sprite in sauv de fond (save background). (Careful! Do not give the same place to two different sprites, since the picture would be poorly restored).


The music

Click on the music (musique) icon or press the F9 key to activate the music box. You have the possibility of 4 different types of music:

  • The chip music
  • Soundtracks(amiga)
  • STF digital files
  • STE digital files (STE only!)

THE CHIP MUSIC

Select musical chips by clicking on soundchip.

You need to load a music with the load option. If you try to load an unknown musical format (apart from mad max, whittaker) an information box will appear and tell you (in bloody French) and the loading will be stopped. Once loaded you can listen to the music loaded by clicking on the listening (ecoute) option. (press the space bar when you want the music stop). You can store it by clicking on the option store and by giving a name to the file.

The erase option enables you to erase the music, since even if it isn't going to be used in your demo, it is still taken into account for safekeeping.

For chip music, you can define the number of the music to be listened to by using the number parameter of music, indeed, such music can include several different parts.

Validate the music in the validate option of the pull down menu and it will be played back in your demo.

The Soundtracks

Click on the soundtracks to activate this mode. You can then load an Amiga module. (Careful, there is no check when loading. i.e if you load the wrong file you risk "crashing" your machine). The loading, storing, listening & erasing are the same as previously explained.

The Digitization

Click on digit, the option of loading etc. are identical. You can indicate the frequency of listening (4.9, 7.68, 9.6 and 15 khz) with the arrows. You can indicate if your digital music is signed or not.

+000/+255->Digital not signed. -128/+128->Digital signed.

To know which mode to use. You need to listen to the music. If it seems unclean, change the mode by clicking on -128/+128 or vice versa.

-On STE. You can have access to mode STE by clicking on it, at that time you must indicate your frequency(6.25, 12.5, 25 and 50 khz) with the arrows.

Equalizers

Equalizers are in the music box, to activate one equalizer during your demo you must activate it with the validation menu. You can define the type of your equalizer with arrows(the name of the corresponding equalizer appears). To place your equalizer on the screen of your demo, modify the column and line parameters with the arrows.

The parameters directions 1 and 2 indicate the direction of variation of the diodes: i.e top and bottom-i.e right/left. You can also indicate on which plan your equalizer will be.

The equalizers do not vary with the digit STE.

The Borders

To define the extra borders of your screen click on the border icon or press F7.

To activate the top borders, you need to select it. You then get 29 extra lines for your screen. To activate the bottom of edge you select it. You then get 45 extra lines.

You can load a bit of picture with the function load extra background. This picture is in degas or neo format and it will only be loaded on the first 74 lines of this picture. This bit of picture is loaded in the buffer number 4.

You can have a look at it or erase it with the corresponding functions.

You also have the possibility to stagger the main background picture by 199 lines max to center your picture with the active borders.

The borders do not function on TT.

Origins of Documentation

This documentation was originally written in French by Barthimus of the cracking Acadamy translated and re-typed by Karadoc of Adrenalin 1992, since then it has been modified here on the wiki.


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