<<>><<>>› 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 )›