CRITTERS, BY JOE WALSH››The Critters program is my second›foray into the world of Artifical›Life (A-Life, or AL).  It is also›my first assembly language program›(other than the piddling programs›typed in from the book Atari Roots,›and the even more piddling programs›I made up to teach myself the›language).  Finally, Critters is a›work-in-progress.››Simply put, the program creates a›"world" on your screen, and borders›it with walls.  Then it randomly›places some Critters (some male,›some female (males are inverse video,›females are normal video)) and some›plants around the screen.››Subsequently, the Critters and›plants live by the rules I have›given for that world.  It's›pretty straight-forward.  Critters›can move, fight, reproduce, eat›plants, eat dead critters (yuck!),›or stay still.  Critters decide what›to do based on what they find›around them, and their "DNA".››Plants have a much simpler life.›They grow from seedlings to full›plants, then wilt and die.  When›they are at or near their full›growth, they can spore another›plant (if there is room for them to›do so, and if the wind is blowing›in that direction).››It's fun to sit and watch this stuff.›I am very interested in perpetually›changing display programs, so I›enjoy just sitting and watching›them go.  Others may want to dabble›in this little world, so I have›provided a couple of meager›controls:››OPTION - Press this key to cause›plants to sprout in empty spaces.›Since the program runs through the›screen so fast, you don't have to›hold it down for long.  But, since›plants die out so quickly (twice›as quickly as all but the weakest›and least fortunate critters),›you may have to do this frequently›(or keep pressing it continuously›for a while) in order to get the›level of plant life you desire.››SELECT - Press this key to cause›Critters to be instantly born in›empty spaces.  Since critters live›relatively long lives, just a tap›of this key is usually enough to›put plenty of Critters on the›screen.››Finally, you may press the START›button to end the program and return›to DOS.  A couple of caveats, though:›1)  It only checks this key just›before it starts checking each›square for life from the top of the›screen down.  In other words, it›checks this key only about once every›second.  So, you may have to hit it›twice or so before it realizes you›want to quit (or just hold it down›for a second).  2)  While Atari DOS›clears the screen before putting it's›menu up, SpartaDOS does not, so you›end up with a screen filled with›characters.  Just type SHIFT-CLEAR›to clear the screen.  I don't have›MYDOS, so I don't know what happens›in that system when you exit to›DOS.››I hope you enjoy the program!›Let me know what you think.  I can›be found on the comp.sys.atari.8bit›newsgroup, or you can email me at›ransom22@delphi.com.›››CREDIT WHERE IT IS DUE DEPT.:››I couldn't have made this program›without the following:››Atari 8-bit computers - my first›computer, and still the best.››Atari Roots, by Mark Andrews -›I thought I'd never find a book on›Atari Assembler that explained things›beyond how to add and subtract.›This book is great, and highly›recommended if you want to learn›ASM.››The people at OSS for putting out›the MAC/65 cart.›This includes Mr. Dunion, for his›Dunion's Debugging Tool, which is›included in the Mac/65 cart.››Mike at Fine Tooned Engineering,›for making the Mac/65 cart available›again.››Carole Borowski, for everything.››David Tipton, for making me realize›that it was time to get back into›the Atari 8-bit world after a six-›year hiatus.››All the kind folks at comp.sys.atari.›8bit, Atari Classics (both old and›new), and Computer Currents for›providing support to our community.››And to you, the user, for sticking›with the best computer platform›around.››- Joe Walsh›09/23/95›