C64 Games

Used In The Main Program Without Permanently Affecting Their Values

COMAL'S TURTLE GRAPHICS ARE THE BEST AVAILABLE ANYWHERE. THE COMMANDS ARE VIRTUALLY IDENTICAL TO COMMODORE LOGO, BUT THE TURTLE IS FASTER. BESIDES THE TURTLE. THERE ARE ALSO POINT-PLOT GRAPHICS COMMANDS WHICH ALLOW YOU TO PLOT USING X-Y COORDINATE GRAPHICS (THIS INCLUDES FILL. THE MOST USEFUL AND NEGLECTED OF ALL GRAPHICS COMMANDS)) SPRITES CAN BE EASILY DEFINED AND MANIPULATED, TOO. IN ALL, THERE ARE OVER 50 GRAPHICS COMMANDS.

WHY ALL THE ENTHUSIASM? BECAUSE COMAL IS A COMPOSITE OF THE BEST FEATURES OF THE MOST POPULAR PROGRAMMING LANGUAGES. IT COMBINES THE FAMILIARITY OF BASIC COMMANDS WITH THE STRUCTURED PROGRAMMING ENVIRONMENT OF PASCAL AND, IN THE COMMODORE 64 VERSION, THE TURTLE GRAPHICS OF LOGO. IT ALSO INCORPORATES A 'THREE-PASS RUN-TIME COMPILER" THAT MAKES COMAL AN AVERA6E OF THREE TIMES FASTER THAN BASIC. AND THE COST IS ABOUT AS REASONABLE AS YOU CAN GET: IT'S FREE. IF YOU CAN FIND COMAL AT SCHOOL OR IN YOUR LOCAL USERS GROUP. YOU CAN MAKE A COPY FOR YOUR OWN USE. IF YOU CAN'T FIND IT, YOU CAN GET A COPY WITH DEMO PROGRAMS FOR $19.95 +$2.00'SHIPPING FROM THE COMAL USERS GROUP,USA,LTD.

THE CURRENT VERSION OF COMAL FOR THE COMMODORE 64 IS COMAL 0.14. IT IS DISK-LOADED AND COMES WITH DEMO PROGRAMS AND HELP FILES. THE HELP FILES CONTAIN LISTS DF COMAL KEYWORDS, WITH EXAMPLES OF PROPER SYNTAX; THE DEMO PROGRAMS' WILL SHOW YOU HOW TO USE COMAL COMMANDS AND TURTLE GRAPHICS. A SINGLE-DRIVE DISK-COPY UTILITY IS INCLUDED TO HELP YOU MAKE BACKUP COPIES FOR YOURSELF AND COPIES TO GIVE TO YOUR FRIENDS!

DISK I/O, PRINT FORMATTING, AND KEYBOARD INPUT ARE ALL IMPROVED'OVER BASIC, WITH ADDITIONAL KEYWORDS TO SIMPLY DO MANY THINGS THAT WERE IMPOSSIBLE OR REQUIRED MACHINE CODE LINKS TO DO FROM BASIC. HOWEVER, IF YOU FEEL THE NEED TO LINK INTO MACHINE LANGUAGE, THE FAMILIAR PEEK, POKE, AND SYS ARE STILL AVAILABLE.

THE MANUAL FOR THIS LAN6UA6E IS THE 'COMAL HANDBOOK' BY LEN LINDSAY. AVAILABLE SEPERATELY FOR »18.95 + »2.00 SHIPPIN6. YOU NEED THE HANDBOOK TO BE ABLE TO USE COMAL EFFECTIVELY. IT EXPLAINS THE PROPER SYNTAX FOR COMMANDS AND HON THEY WORK, AND GIVES CLEAR EXAMPLES OF HON TO USE THEM. THE BOOK IS WELL-ORGANIZED AND CLEAR (IT'S GENERALLY REGARDED AS ONE OF THE BEST REFERENCE BOOKS AROUND FOR ANY PROGRAMMING LANGUAGE, PERIGD) AND IS THE PERFECT REFERENCE TOOL FOR THOSE MHO ARE ALREADY PROGRAMMING. SINCE THE MANUAL IS INTENDED TO DOCUMENT ALL OF THE COMMODORE VERSIONS OF COMAL. AND THE TURTLE GRAPHICS EXTENSIONS ARE UNIQUE TO THE COMMODORE 64 IMPLEMENTAION, THEY ARE NOT DOCUMENTED IN THE COMAL HANDBOOK. A GRAPHICS MANUAL IS PROMISED FOR LATER THIS YEAR; UNTIL THEN, YOU WILL HAVE TO FIGURE OUT THE GRAPHICS WITH THE AID OF THE DISK HELP FILES. A GOOD LOGO BOOK MIGHT HELP, TOO, SINCE THE TURTLE GRAPHICS ARE ALMOST IDENTICAL TO LOGO'S. IF YOU ARE A PROGRAMMING NOVICE. OTHER INSTRUCTIONAL BOOKS ARE AVAILABLE. SUCH AS 'BEGINNING COMAL' BY BORGE CHRISTENSEN, THE ORIGINATOR OF THE LANGUAGE. A COMPANION DISK IS ALSO AVAILABLE FOR EACH BOOK AT ADDITIONAL COST.

LIKE BASIC, COMAL IS AN INTERACTIVE LANGUAGE. THIS MEANS THAT YOU CAN 'TRY OUT' YOUR CODE AS YOU GO BY RUNNING ALL OR PART OF THE PR06RAM. THIS ABILITY IS TAKEN FOR GRANTED BY MOST BASIC PROGRAMMERS, BUT TO ANYONE WHO USES A LANGUAGE LIKE PASCAL, WHICH REflUIRES A SEPERATE EDITDR AND COMPILER, IT CAN SAVE MANY HOURS OF SWAPPING FILES DURING THE DEBUGGING PROCESS.

COMAL IS AN EXCELLENT LANGUAGE. BUT NOTHING IS PERFECT. A FEW FAMILIAR KEYWORDS ARE MISSING, SUCH AS CLR, WAIT, TI*. AND STRt. IN MOST CASES, IT IS POSSIBLE, HOWEVER, TO DEFINE A PROCEDURE OR FUNCTION TO TAKE THEIR PLACE. THERE ARE ALSO NO SOUND COMMANDS, AN OMISSION SHARED WITH HOST OF THE LANGUAGES NOW AVAILABLE FOR THE COMMODORE 64; IT'S A SHAME THAT THE SID CHIP IS SO OFTEN OVERLOOKED. THE ONLY REALLY SERIOUS DRAWBACK TO DISK-LOADED COMAL VERSION 0.14 IS THAT IT LEAVES YOU WITH ONLY ABOUT 10K OF AVAILABLE

MEMORY. (THERE IS ADDITIONAL SPACE RESERVED FOR THE 8K HI-RES SCREEN. SO HI-RES GRAPHICS WILL NOT EAT UP PART OF YOUR PROGRAM MEMORY.) EVEN WITH THE MEMORY-SAVING STRUCTURED PROGRAMMING ENVIRONMENT OF COMAL. THIS WILL PROBABLY LIMIT YOU TO GAME AND HOME APPLICATIONS.

THE EDITOR IS ONE OF THE BEST FEATURES OF COMAL. BESIDES SUPPORTING THE C64'S BUILT-IN FULL SCREEN EDITOR. THE COMAL EDITOR FEATURES AUTOMATIC LINE NUMBERING AND RENUMBERING AND CHECKS SYNTAX AS YOU ENTER YOUR PR06RAM, IF YOU MAKE AN ERROR. YOU ARE TOLD WHAT THE ERROR IS AND THE CURSOR IS PLACED AT THE POINT IN THE LINE WHERE THE ERROR OCCURS. WHEN YOU HAVE TYPED IN THE CORRECTION, THE ERROR MESSAGE DISAPPEARS FROM THE SCREEN. REPLACING ANY TEXT THAT IT MAY HAVE OVERWRITTEN. WHILE IT IS STILL POSSIBLE TO MAKE LOGICAL PROGRAMMING ERRORS IN COMAL, THE EDITOR MAKES IT IMPOSSIBLE TO END UP WITH ANY SYNTAX ERRORS.

COMAL PROGRAM LISTINGS ARE UNIQUE. TOO. THEY RESEMBLE PASCAL 'PRETTY* LISTINGS, WITH AUTOMATIC INDENTATION OF PROGRAM STRUCTURES AND LOOPS. LINE NUMBERS ARE RETAINED FOR EASE OF EDITIN6. EVEN TH0U6H THEY ARE NOT USED BY THE PROGRAM ITSELF. THIS POWERFUL EDITOR MAKES COMAL THE MOST USER-FRIENDLY LANGUAGE AROUND.

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ON THE PLUS SIDE. THE DISK VERSION OF COMAL IS COPYABLE AND FREE. THIS MAKES IT PERFECT FOR SCHOOL SYSTEMS WHICH WISH TO TEACH GOOD PROGRAMMING SKILLS, AND FOR USERS'S GROUPS AND INDIVIDUALS WHO WANT A LANGUAGE FOR THEIR PERSONAL APPLICATIONS THAT IS POWERFUL, FRIENDLY, AND INEXPENSIVE. BUT WHAT ABOUT THE PROFESSIONALS WHO NEED MORE MEMORY FOR COMPLEX APPLICATIONS? WELL. FOR NOW IT IS POSSIBLE TO CHAIN PROGRAMS TOGETHER AND SHARE DATA FILES, A LESS THAN PERFECT SOLUTION BUT ONE THAT WORKS. AND LATER THIS YEAR. A CARTRIDGE CONTAINING THE EVEN MORE POWERFUL VERSION 2.00 COMAL IS PROMISED FROM NONE OTHER THAN COMMODORE ITSELF, AND IT WILL OVERCOME ALL OF THE NEGATIVES I'VE MENTIONED. VERSION 2.00 WILL LEAVE ABOUT 30K OF AVAILABLE MEMORY, AND WILL INCLUDE SOUND COMMANDS. ADVANCED LOOP STRUCTURES, STRt. TIME, EXTERNAL PROCEDURES. AND MUCH MORE, AND SHOULD RETAIL FOR UNDER $100. THIS MAKES IT A BETTER FEATURES-PER-DOLLAR BARGAIN THAN ANY OTHER LANGUAGE CURRENTLY AVAILABLE FOR THE COMMODORE 64. THE ARGUMENT, THEREFORE, IS TO GET DISK-LOADED COMAL VERSION 0.14 NOW AND LEARN TO USE IT, AND THEN ADVANCE TO THE CARTRIDGE VERSION WHEN IT BECOMES AVAILABLE IF YOU NEED THE ADDITIONAL PROGRAMMING POWER. I BELIEVE THAT THOSE WHO JOIN THE 50,000 PEOPLE ALREADY PROGRAMMING IN COMAL MAY WELL PROVE TO BE THE PIONEERS OF THE STANDARD PROGRAMMING LANGUAGE OF THE NEXT DECADE.

SUPPORT FOR COMAL HERE IN THE U.S. COMES FROM THE COMAL USERS GROUP, WHICH IS CAPTAINED BY LEN LINDSAY, THE FATHER OF COMPUTE! MAGAZINE. THEY CAN SUPPLY COMAL INFORMATION, BOOKS, AND DISKS, AS WELL AS THE LANGUAGE ITSELF. CONTACT:

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