MAGIC WINDOW FOR THE ATARI 400/800 FROM QUICKSILVA CHARACTER GENERATOR WITH FULL JOYSTICK CONTROL Define characters on an 8 x 8 grid. Save to tape. Load from tape. Freely merge character sets into existing programs. Hex and Dec O/Ps. Character manipulation: Mirror, rotate, invert, left, right, up, down, cancel. Redefine the whole character set. Also works in colour modes. Excellent examples supplied. Author: Martin Walker MAGIC WINDOW FOR THE ATARI 400 AND 800 WITH 16K OF RAM OR GREATER Created by Martin Walker INTRODUCTION Maps, circuit diagrams, planes, pictures and games are all ideal applications for redefined symbols and characters to replace the standard ATARI set. MAGIC WINDOW is a quick and easy way to create new character sets and incorporate them with your own BASIC programs. The flexible editor uses full joystick control and a special screen display (with Player/Missile graphics and machine code) to show any design in normal and multicolour graphics modes simultaneously as well as in the enlarged 'window'. A special feature is the sketchpad which allows you to create large multiple part characters or animate whole groups before committing them to your new set. After the new characters are created (or modified using the extensive command menu), MAGIC WINDOW writes its own program incorporating the new set, and saves it onto cassette. Unlike most other systems, the characters are within the BASIC program, are not lost on SYSTEM RESET, and can be CSAVED with the rest of your own program. INSTRUCTIONS FOR USE 1. Running the Program Plug a joystick into the number 1 socket on the front of the computer. With the BASIC cartridge inserted, type CLOAD and use the 410 Program Recorder in the usual way to load the program. When the tape has stopped, and the READY prompt is on the screen, type RUN and press RETURN. 2. The Screen Display When the screen display appears, you will see three main areas: a) The editor with the window sketchpad and menu of commands occupying the top half of the screen. b) The prompt line (which shows 'CHOOSE CHARACTER' when first run) occupying the middle portion of the screen. c) The complete NEW SET (your own characters as yet unmodified) and the OLD SET (the standard ATARI characters) both towards the bottom of the screen. 3. Using the Joystick When the program is first run, the cursor will appear at the top-left corner of the window as a small square (the same size as normal GRAPHICS 0 characters). The cursor is moved smoothly and in all directions using the joystick. Wraparound is also implemented so that the cursor can exit from the left or right-hand side of the screen and reappear on the opposite side. Commands are given to the cursor by placing it over the appropriate screen area and pressing the trigger. 4. Window Edit Mode Press the joystick trigger with the cursor placed over the window at the left side or an edit command on the right side of the screen. The prompt line will change to 'WINDOW EDIT MODE' and the cursor will also change colour. Once in edit mode, any further trigger commands will be carried out until either the character in the window is transferred to your new set, or the command CANCEL is used, both of which will cause the prompt line to return to 'CHOOSE CHARACTER' mode. a) The Window - With the cursor placed over the section of the window to be changed, press the trigger - the area behind the cursor will be filled or cleared, depending on its previous state. Press the trigger again to reverse the procedure. To the right of this are the sample characters in the normal GRAPHICS 2, 0 and 1 modes. These all change with the window display. b) The menu of Commands - At the right side of the editor are the 10 commands used to modify window or change the function of the program. To use, place the cursor anywhere over the required command and press the trigger while in 'WINDOW WDIT MODE'. c) The Sketchpad - In the middle of the edit display, the sketchpad is an area of 4 x 4 characters which at the start of the program is filled with the window characters. It can thus be used to see how large groups of similar symbols will look in close proximity. However, it has a much more versatile function. When creating characters you may want to have (temporarily) several variations on one design, but not necessarily want to commit yourself to writing all of them to the new set. Alternatively, you may be designing large multiple part characters (for example those pieces in a chess program) which are formed from several individual segments joined together. These are ideal tasks for the sketchpad. There are two commands associated with it, HOLD will print the current sketch permanently onto the sketchpad. Modifications to the window will then have no further effect on the sketch unless individual parts of the sketchpad are overwritten by placing the cursor over them and pressing the trigger whilst in 'WINDOW EDIT MODE'. WIPE removes all the characters from the sketchpad and presents a clean sheet for further use. To use the sketchpad to create your own multiple characters, proceed as follows: i) First WIPE the sketchpad clean. ii) Create the first part of the character using the editor and window and then move the cursor to your chosen part of the sketchpad whilst still in the 'WINDOW EDIT MODE'. iii) Press the trigger. Your character will appear behind the cursor. This can be repeated any number of times until the sketchpad is full if required. All these characters will now be updated when the window is further modified. iv) When the first part of the character is complete, use HOLD to make the sketch permanent. v) Return to the window to create the next part of the character. This second part can be moved to another part of the sketchpad in the same way as the first, and as each part is perfected it can be made permanent using HOLD in the way a character of up to 4 x 4 can be edited in a similar manner. d) Transferring a finished character the NEW SET - When each character is perfected it may be placed into your NEW SET by simply moving the cursor over a character to be replaced. Pressing the trigger will then transfer the window character or that position in the NEW SET. Once transferred, MAGIC WINDOW returns to 'CHOOSE CHARACTER' mode. 5. Choose Character Mode This mode is obtained at three times viz. at the start of the program run, after transferring a window character to the NEW SET, and after using the CANCEL command from the edit mode. When the prompt line shows 'CHOOSE CHARACTER', the cursor will also change colour as a reminder. The character may come from one of three places: a) The NEW SET. b) The OLD SET. c) The SKETCHPAD. It is selected by be moving the cursor to it and pressing the trigger, when it Will appear in the window and MAGIC WINDOW will return to 'WINDOW EDIT MODE' (if you have chosen the wrong character from the NEW SET, a quick way to change it is to leave the cursor over the same character and press the tigger again to transfer the character back unchanged. The character will then return to 'CHOOSE CHARACTER' mode). 6. Command Menu Details a) SCREEN - This command enables you to use the special four colour text modes as easily as the one colour modes. Press the trigger once and the simple GRAPHICS 0 character, the sketchpad characters and the NEW SET all change to four colour mode. The characters are now only four pixels wide, but each can be one for four colours, including the background. These are obtained by the four combinations of two adjacent pixels, as shown in the command menu on selecting this mode. The markings at the top and bottom of the window show the positions of these four pairs. Leaving both pixels blank gives the background colour (black). Filling only the right-hand pixel of any pair gives red, and only the left hand gives green. Filling both pixels will give blue. To change back to single colour mode at any time, simply press the trigger again over the SCREEN command. b) DATA - The numeric value for each row of the window character is given with this command. It can be used for reference or for advanced programming techniques. Press the trigger once to give decimal data values alongside the window. Pressing again gives the hexadecimal values. To return to WINDOW EDIT MODE, press the trigger a third time. c) MIRROR - A backwards image of the character is given, as in the reflection of a mirror. d) ROTATE - This turns the character round in a clockwise direction, and is useful for creating characters pointing in four different directions for animation. Four rotations returns the character to its original position. e) INVERT - This acts like the ATARI keyboard - creating an inverse character. It may be cancelled by pressing the trigger once more. f) LEFT, RIGHT, UP and DOWN - Shifting the whole window in each direction, one line at a time. g) CANCEL - Should you wish to clear the window completely, and return to 'CHOOSE CHARACTER' mode. 7. Loading and Saving Character Sets Immediately to the left of the command menu, two more codes (L and S) are shown on the screen. Placing the cursor over these at any time will allow you to Load and Save your new character sets. L will enable you to retrieve previously saved sets for further modification. Use the 410 Program Recorder in the normal way when you hear a single 'beep'. 'S' will write a BASIC program onto cassette with all your new characters within it. Two 'beeps' will sound in the normal way. 8. Using Character Sets Created by MAGIC WINDOW There are three sample character sets included with this program. These are on the cassette directly after the main program. Use the 'L' command to load each in turn. The first is an example of a redefined script, and illustrates how the normal letters and numbers can be modified to suit a particular application. The second shows some of the possibilities of 'artefacts'. These occur due to the limitations in all television sets when displaying GRAPHICS 0 characters, and allow four different colours even while using normal text. A lot can be learned by studying these samples. The third has been designed to show the true four colour mode of the ATARI. When loaded, use the SCREEN command to see the set in its intended screen mode. It gives a variety of symbols to be used in your games. When you have finished saving your own sets to cassette, they may be retrieved for your own program (or merged with it) by using the using the BASIC command ENTER"C". Just make sure that you do not use line numbers 0 to 11. If you decide to further modify your characters when you have finished your own program, the command LIST"C,0,11" will create on cassette a program which can be re-entered into MAGIC WINDOW by using the 'L' command. To use a four colour mode set in your own programs, type the following BASIC lines as shown below into your own listing. 12 DL=PEEK(560)+256*PEEK(561) 13 POKE DL+3,68 14 FOR N=6 TO 28:POKE DL+N,4:NEXT N (C) Copyright 1982 Quicksilva Ltd. All rights of the producer, and of the owner, of the work are reserved. Unauthorised copying, hiring, lending, public performance and broadcasting of this cassette is prohibited. The publisher assumes no responsibility for errors, nor liability for damage arising from its use.