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POHelping understanding RedCode
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copied!<p>I'm trying to learn redcode, because it looks fun to make a bot.</p> <h2>Introduction</h2> <p>For those who don't know what redcode is, here's a short explanation. It's an ASM-like language, but far more easy and stripped. It is used to write little programs that need to shut down other programs in virtual memory. (See for more info here: <a href="http://vyznev.net/corewar/guide.html" rel="nofollow noreferrer">http://vyznev.net/corewar/guide.html</a>)</p> <p>Here's a piece of code:</p> <pre><code>;redcode ;name Mice ;author Chip Wendell ;strategy paper (replicator) ;history Winner of the 1986 ICWS tournament Top dat #0, #0 Start mov #12, Top Loop mov @Top, <Target djn Loop, Top spl @Target,0 Spacer equ 653 add #Spacer,Target jmz Start, Top Target dat #0, #833 end Start </code></pre> <h2>Problem</h2> <p>The basic strategy is to replicate itself to another place, and the fork the process. What I don't understand is this rule:</p> <pre><code>Loop mov @Top, <Target </code></pre> <p>I understand the meaning of this line. It says, move the B-Field of target to the line where the B-Field of top points, and decrease the value of the B-Field of target.</p> <p>When loop is executed for the first time, the first line will be:</p> <pre><code>Top dat #0, #12 </code></pre> <p>As far as I get, the line with Loop means: Move the instruction 12 lines ahead (filled with dat #0, #0) to line 833.</p> <p>But when this code is executed, the line of code is placed at line 839.</p> <p>Does someone understand what is happening really?</p>

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