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<div id="preamble">
</div>
<div id="content">
<h1 class="title">6502Arch</h1>
<div id="table-of-contents">
<h2>Table of Contents</h2>
<div id="text-table-of-contents">
<ul>
<li><a href="#sec-1">1 Addressing modes</a>
<ul>
<li><a href="#sec-1-1">1.1 Absolute</a></li>
<li><a href="#sec-1-2">1.2 Zero-page</a></li>
<li><a href="#sec-1-3">1.3 Zero-page, X</a></li>
<li><a href="#sec-1-4">1.4 Zero-page, Y</a></li>
<li><a href="#sec-1-5">1.5 Immediate</a></li>
<li><a href="#sec-1-6">1.6 Relative</a></li>
<li><a href="#sec-1-7">1.7 Implicit</a></li>
<li><a href="#sec-1-8">1.8 Indirect</a></li>
<li><a href="#sec-1-9">1.9 Indexed Indirect</a></li>
<li><a href="#sec-1-10">1.10 Indirect Indexed</a></li>
</ul>
</li>
<li><a href="#sec-2">2 Stack</a></li>
<li><a href="#sec-3">3 Jumping</a></li>
</ul>
</div>
</div>
<div id="outline-container-1" class="outline-2">
<h2 id="sec-1"><span class="section-number-2">1</span> Addressing modes</h2>
<div class="outline-text-2" id="text-1">
<p>
has a 16-byte address bus.
</p>
</div>
<div id="outline-container-1-1" class="outline-3">
<h3 id="sec-1-1"><span class="section-number-3">1.1</span> Absolute</h3>
<div class="outline-text-3" id="text-1-1">
<ul>
<li>Full memory location specified, i.e. $c000
</li>
<li>65536 bytes of addressable memory (2<sup>16</sup> duyyy)
</li>
</ul>
</div>
</div>
<div id="outline-container-1-2" class="outline-3">
<h3 id="sec-1-2"><span class="section-number-3">1.2</span> Zero-page</h3>
<div class="outline-text-3" id="text-1-2">
<ul>
<li>1 byte adress, i.e. $c0, 256 bytes adressable
</li>
<li>faster, takes less program space
</li>
</ul>
</div>
</div>
<div id="outline-container-1-3" class="outline-3">
<h3 id="sec-1-3"><span class="section-number-3">1.3</span> Zero-page, X</h3>
<div class="outline-text-3" id="text-1-3">
<ul>
<li>Relative adressing <span style="text-decoration:underline;">within</span> the zero page.
</li>
<li>Adds the value in reg. x with a 1-byte adress
</li>
<li>i.e. STA $a0, X
</li>
<li>Address wraps around if the addition is larger than 1 byte
</li>
</ul>
</div>
</div>
<div id="outline-container-1-4" class="outline-3">
<h3 id="sec-1-4"><span class="section-number-3">1.4</span> Zero-page, Y</h3>
<div class="outline-text-3" id="text-1-4">
<ul>
<li>equiv to zero-page, X but can only be used with LDX and STX
</li>
</ul>
</div>
</div>
<div id="outline-container-1-5" class="outline-3">
<h3 id="sec-1-5"><span class="section-number-3">1.5</span> Immediate</h3>
<div class="outline-text-3" id="text-1-5">
<ul>
<li>i.e. #$c0
</li>
<li>loads immedate number into register
</li>
</ul>
</div>
</div>
<div id="outline-container-1-6" class="outline-3">
<h3 id="sec-1-6"><span class="section-number-3">1.6</span> Relative</h3>
<div class="outline-text-3" id="text-1-6">
<ul>
<li>i.e. $c0, or label
</li>
</ul>
</div>
</div>
<div id="outline-container-1-7" class="outline-3">
<h3 id="sec-1-7"><span class="section-number-3">1.7</span> Implicit</h3>
<div class="outline-text-3" id="text-1-7">
<ul>
<li>when operation doesn't deal with memory
</li>
</ul>
</div>
</div>
<div id="outline-container-1-8" class="outline-3">
<h3 id="sec-1-8"><span class="section-number-3">1.8</span> Indirect</h3>
<div class="outline-text-3" id="text-1-8">
<ul>
<li>Uses absolute address to get another address
</li>
<li>first address is LSB of address, following byte is MSB
</li>
</ul>
</div>
</div>
<div id="outline-container-1-9" class="outline-3">
<h3 id="sec-1-9"><span class="section-number-3">1.9</span> Indexed Indirect</h3>
<div class="outline-text-3" id="text-1-9">
<ul>
<li>i.e. LDA ($c0, X)
</li>
<li>Take a zero page adress and add the value in reg. x to it, look up 2 byte address
</li>
</ul>
</div>
</div>
<div id="outline-container-1-10" class="outline-3">
<h3 id="sec-1-10"><span class="section-number-3">1.10</span> Indirect Indexed</h3>
<div class="outline-text-3" id="text-1-10">
<ul>
<li>zero page address dereferenced then Y is added to it
</li>
</ul>
</div>
</div>
</div>
<div id="outline-container-2" class="outline-2">
<h2 id="sec-2"><span class="section-number-2">2</span> Stack</h2>
<div class="outline-text-2" id="text-2">
<ul>
<li>lives in memory between $0100 and $01ff
</li>
</ul>
</div>
</div>
<div id="outline-container-3" class="outline-2">
<h2 id="sec-3"><span class="section-number-2">3</span> Jumping</h2>
<div class="outline-text-2" id="text-3">
<ul>
<li>JSR/RTS: Jump to subroutine and return from subroutine
</li>
</ul>
</div>
</div>
</div>
<div id="postamble">
<p class="date">Date: 2014-09-25T21:09-0400</p>
<p class="author">Author: Alex Weisberger</p>
<p class="creator"><a href="http://orgmode.org">Org</a> version 7.9.3f with <a href="http://www.gnu.org/software/emacs/">Emacs</a> version 24</p>
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