<<>><<>>¢ A REVIEW of¢ "ADVANCED PROGRAMING TECHNIQUES FOR¢ YOUR ATARI", Including Graphics &¢ Voice Programs -by Linda M. Schreiber¢ 1983 Tab Books Inc. Blue Ridge Summit,¢ PA. March 16, 1996¢ -by Joseph E. Hicswa¢¢ (Ed. I like this next paragraph of¢ JOE's which explains the type of¢ attitude that has kept our 8 BIT micro¢ afloat. A.P.)¢¢ NOTE: My Public Domain article, has no¢ rights reserved. It is for the benefit¢ and enhancement of any and all ATARI¢ owner/users.¢¢ I'm an ATARI devotee who is a¢ believer in education and literacy. ¢ Of course, I'm unable to attend the¢ class of every teacher; nor can they¢ personally visit or tutor me. Teachers¢ (authors) write. I read. They bring¢ knowledge to me. I read books when on¢ a bus, plane or train. I read books¢ at work during breaks and lunch I¢ constantly review, re-read books, (and¢ DOC's) related to my ATARI system. ¢ With each re-reading I almost always¢ learn something new. I know I had read¢ it before, but hastily! Had skipped¢ over it! Did not know enough to¢ understand it! Or did not use it¢ enough to keep it in my mind! All¢ this happened with the book mentioned¢ above.¢¢ I got it about 8 years ago and¢ read it several times. From this last¢ particular reading I learned to¢ translate machine code into a BASIC¢ language program. BASIC, especially¢ ATARI TURBO BASIC is my preference¢ because of easy-to-read structure.¢ High level languages meant learning¢ something hard, like Latin, Polish, or¢ some other hard language. But I'm¢ happy with ATARI BASIC. The BASIC¢ language programs permit myself and¢ others to list, examine, improve and¢ share with other ATARI owner/users.¢¢ Linda wrote about, and explains¢ programming techniques in easy-to-read¢ understandable format. She reinforces¢ her topics with 64 programs with REM¢ statements and line by line¢ explanation. Familiarity with BASIC¢ language is helpful but not critical¢ as she guides you through the BASIC¢ programs. The book is replete with¢ easy programs for the reader to enter¢ into the computer and see the marvels¢ on screen. With a little ingenuity¢ readers can alter and improvise those¢ programs that fascinate ATARI owner¢ /users. ¢¢ Programing makes me feel like a¢ demigod, whereby I get an idea then¢ program it to become reality on¢ the computer screen. What a happy¢ accomplishment!¢¢ Linda's book teaches people to¢ write outstanding programs and make¢ their ideas a reality also. In her¢ introduction Linda explains she wrote¢ for the person who wants to get more¢ special effects, more sounds and more¢ graphics from an ATARI computer. She¢ does this in fourteen chapters. ¢ Starting with an explanation of the¢ binary system, the reader is guided¢ through all of the following, such as¢ ANTIC (text & graphic displays),¢ animation, how to speed up a program,¢ machine language subroutines, display¢ list interrupts, scrolling, page¢ flipping, sound, key-board magic,¢ memory locations to do fancy screen¢ displays, workings of a disk drive to¢ make boot disks, voice (audio)¢ programs for Cassette users. ¢¢ Linda explains where the¢ character set is located, how to copy¢ from ROM into RAM and alter it for¢ fascinating color displays on screen¢ by simply pressing computerboard keys.¢ (An altered character set was used to¢ program EASTERN FRONT--WWII battles in¢ Europe).¢¢ For years I had wanted to learn¢ about the numbers programmers used in¢ their DATA lines. People who knew and¢ understood them had tried explaining,¢ but I couldn't grasp it. Then I¢ discovered something in chapter 7 --¢ DISPLAY LIST INTERRUPTS-- using¢ machine language subroutines. It came¢ through loud and clear. The numbers¢ are machine language codes poked into¢ computer memory to speed up the¢ program and make it run smoothly. The¢ codes are tokens (the alphanumeric¢ characters in an ATARI-ATASCII-list.¢ Depending upon instructions, a¢ computer treats a number as a token or¢ number. As tokens, 72 represents¢ UPPER CASE H, 198 is a graphics¢ character and 162 is inverse quote¢ marks. When told there is a machine¢ code token in the memory location, the¢ computer performs that certain¢ function.¢¢ Dec Code Mach Code¢ 72 = PHA ;Push accumulator¢ on the stack.¢ 138 = TXA ;Transfer index X¢ to accumulator.¢ 162,100 = LDX #100 ;Load index X¢ with 100¢¢ Now I don't understand the¢ mnemonics, but it was a revelation non¢ the less. All I have to do is make a¢ list of decimal codes and respective¢ machine language codes. The list would¢ then be used to translate machine¢ language program into my BASIC¢ language program to poke machine code¢ numbers into computer memory.¢¢ A=USR (address). USR tells¢ computer it is a machine code routine,¢ address, is where it begins. The book¢ reveals memory locations.¢¢ DATA 72,138,162,100¢ FOR L=n to n+3:READ D:POKE L,D:NEXT L¢ A=USR(n)¢¢ If unable to find a copy of the¢ book check your local library. They¢ also might have other ATARI books¢ available. After reading Linda's book¢ to discover ATARI secrets, why not¢ tell us about it in an article?¢¢ Happy reading and programming.¢ Looking forward to see an exciting¢ program or article written by you as a¢ result of "ADVANCED PROGRAMMING¢ TECHNIQUES FOR YOUR ATARI" -by Linda¢ M. Schreiber. (Ed. Or any other ATARI¢ book A.P)¢ ( END )¢