diff --git a/docs.py b/docs.py
index dc2e0d0..e97d687 100644
--- a/docs.py
+++ b/docs.py
@@ -1,3 +1,4 @@
+from dataclasses import dataclass
 import datetime
 import re
 import os
@@ -19,7 +20,7 @@ TOC_HTAG_LEVELS = {"1", "2"}
 HOST = "https://bsnk.me"
 TEMPLATES = "templates"
 PAGES_BASE = "pages"
-STATIC = ["images"]
+STATIC = ["images", "static"]
 
 ROOT = os.environ.get("EA_ROOT", "")
 
@@ -42,6 +43,7 @@ SEGA_CONTENTS = {
     "intro.html": ("Introduction to RingEdge 2", ()),
     "hardware": ("Hardware", ()),
     "software": ("Software", {
+        "jvs.html": "JVS",
         "drivers": ("Device drivers", {
             "columba.html": "columba",
             "mxsram.html": "mxsram",
@@ -51,16 +53,15 @@ SEGA_CONTENTS = {
             "mxparallel.html": "mxparallel",
             "mxsmbus.html": "mxsmbus",
         }),
-        "jvs.html": "JVS",
         "security": ("Security", {
             "game.html": "Game encryption",
             "dongle.html": "Dongles",
             "keychip.html": "Keychips",
-        })
+        }),
     }),
     "network": ("Networking", {
         "allnet.html": "ALL.Net"
-    })
+    }),
 }
 CONTENTS = {
     "": EAMUSE_CONTENTS,
@@ -68,6 +69,25 @@ CONTENTS = {
 }
 
 
+@dataclass
+class Part:
+    id: str
+    name: str
+    description: str = None
+    page: str = None
+
+
+PARTS = {
+    "838-14971": Part("838-14971", "Aime NFC daughter board", "NFC RW BD TN32MSEC003S")
+}
+
+
+def part(id):
+    if (part := PARTS.get(id)):
+        return f'<span class="part" tabindex="0">{part.name}<span><span>Part number</span><span>{part.id}</span><span>Description</span><span>{part.description}</span></span></span>'
+    return f'<span class="part">{id}</span>'
+
+
 def generate_xrpc_list():
     output = "<ul>"
     proto = TEMPLATES + "/" + PAGES_BASE + "/proto"
@@ -270,6 +290,7 @@ for base, _, files in os.walk(TEMPLATES + "/" + PAGES_BASE):
                         generate_xrpc_list=generate_xrpc_list,
                         generate_toc=lambda start=1: generate_toc(base, name, route, start),
                         generate_footer=lambda: generate_footer(base, name, route),
+                        part=part,
                     )
                 return handler
 
diff --git a/static/JVST_VER3.pdf b/static/JVST_VER3.pdf
new file mode 100644
index 0000000..ec243ff
Binary files /dev/null and b/static/JVST_VER3.pdf differ
diff --git a/static/jvs_wip.pdf b/static/jvs_wip.pdf
new file mode 100644
index 0000000..735cddc
Binary files /dev/null and b/static/jvs_wip.pdf differ
diff --git a/styles.css b/styles.css
index 9b4a1ee..c37a979 100644
--- a/styles.css
+++ b/styles.css
@@ -174,6 +174,55 @@ footer>*:last-child {
 }
 
 
+.part {
+    text-decoration: underline dotted;
+    text-underline-offset: 2px;
+    position: relative;
+    display: inline;
+    cursor: help;
+}
+
+.part span {
+    display: block;
+}
+
+.part>span {
+    display: none;
+    position: absolute;
+    left: 0;
+    width: 100%;
+    top: 100%;
+    margin: 4px;
+    border: 1px solid currentColor;
+    padding: 8px;
+    background-color: inherit;
+}
+
+.part>span>span:nth-child(2n - 1) {
+    font-weight: 600;
+}
+
+.part>span>span:nth-child(2n) {
+    margin-left: 1rem;
+}
+
+.part:hover>span, .part:focus>span, .part>span:hover {
+    display: block;
+}
+
+figure>figcaption:first-child {
+    margin-bottom: 8px;
+}
+
+mark {
+    background-color: unset;
+    color: unset;
+    font-family: monospace;
+    font-size: 1.2em;
+    text-decoration: underline;
+    text-underline-offset: 1px;
+}
+
 @media (prefers-color-scheme: dark) {
     body {
         background-color: #000;
@@ -189,7 +238,7 @@ footer>*:last-child {
     }
 
     code {
-        background-color: #150a0d;
+        background-color: #221115;
     }
 
     .highlight, img:not(.graphic) {
@@ -209,6 +258,7 @@ footer>*:last-child {
         background: #1c0d11;
         border-color: #3b2b2f;
     }
+
     details code {
         background: #000;
     }
diff --git a/templates/pages/sega/software/comio.html b/templates/pages/sega/software/comio.html
new file mode 100644
index 0000000..e803f65
--- /dev/null
+++ b/templates/pages/sega/software/comio.html
@@ -0,0 +1,292 @@
+{% extends "sega.html" %}
+{% block title %}JVS{% endblock %}
+{% block body %}
+<h1>JAMMA Video Standard - Alternative version</h1>
+<p><b>Note:</b> This page assumes you have read the documentation regarding <a href="./jvs.html">the JAMMA video
+        standard</a>. If you have not, it is recommended to read that first.</p>
+
+<h2 id="frame">Packet framing</h2>
+<figure>
+    <figcaption>Request packet (master->slave)</figcaption>
+    <table>
+        <tr>
+            <td>E0<sub>h</sub></td>
+            <td>n</td>
+            <td>Dest</td>
+            <td>Seq</td>
+            <td><mark>CMD</mark></td>
+            <td><mark>D</mark><sub>0</sub></td>
+            <td><mark>D</mark><sub>1</sub></td>
+            <td><mark>D</mark><sub>2</sub></td>
+            <td>...</td>
+            <td><mark>D</mark><sub>n-5</sub></td>
+            <td><mark>SUM</mark></td>
+        </tr>
+    </table>
+</figure>
+<figure>
+    <figcaption>Response packet (slave->master)</figcaption>
+    <table>
+        <tr>
+            <td>E0<sub>h</sub></td>
+            <td><mark>n</mark></td>
+            <td>Src</td>
+            <td>Seq</td>
+            <td>Status</td>
+            <td><mark>CMD</mark></td>
+            <td>Report</td>
+            <td><mark>D</mark><sub>0</sub></td>
+            <td><mark>D</mark><sub>1</sub></td>
+            <td><mark>D</mark><sub>2</sub></td>
+            <td>...</td>
+            <td><mark>D</mark><sub>n-7</sub></td>
+            <td><mark>SUM</mark></td>
+        </tr>
+    </table>
+</figure>
+
+<h2 id="body">Commands and responses</h2>
+<p>Response packets of this format include a source address, which should match the destination in the request. The
+    sequence number of both the request and response should be the same (? todo: verify this), and should be modulo 32
+    (20<sub>h</sub>).</p>
+<p>While the packet format would suggest it supports multiple commands, I have never observed more than a single command
+    per packet. Response packets include the command number between their packet status and report status bytes.
+</p>
+
+<h2 id="commands">Individual commands</h2>
+<p>The following is a reference table for communication with an {{ part("838-14971")|safe }}. Endpoints required for
+    MIFARE cards are marked with <mark>M</mark>, FeliCa <mark>F</mark>, and LEDs <mark>L</mark>.</p>
+<table style="width: 100%">
+    <thead>
+        <tr>
+            <td>Req</td>
+            <td>Name</td>
+            <td>Code</td>
+            <td>Description</td>
+            <td>Request Size</td>
+            <td>Response Size</td>
+        </tr>
+    </thead>
+    <tbody>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Get Firmware Version</td>
+            <td><code>30</code></td>
+            <td>Retrive the firmware version string</td>
+            <td>0</td>
+            <td>1+</td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Get Hardware Version</td>
+            <td><code>32</code></td>
+            <td>Retrive the hardware version string</td>
+            <td>0</td>
+            <td>1+</td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Radio On</td>
+            <td><code>40</code></td>
+            <td>Enable the NFC radio</td>
+            <td>2</td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Radio Off</td>
+            <td><code>41</code></td>
+            <td>Disable the NFC radio</td>
+            <td></td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Poll</td>
+            <td><code>42</code></td>
+            <td>Retreive a list of NFC devices</td>
+            <td>0</td>
+            <td>3+</td>
+        </tr>
+        <tr>
+            <td><mark>M</mark></td>
+            <td>Select MIFARE tag</td>
+            <td><code>43</code></td>
+            <td></td>
+            <td>1+</td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>44</code></td>
+            <td></td>
+            <td>1+</td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Set MIFARE Classic key</td>
+            <td><code>50</code></td>
+            <td>Provide the key used for MIFARE decryption</td>
+            <td>1+</td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>51</code></td>
+            <td></td>
+            <td>1+</td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>M</mark></td>
+            <td>Read MIFARE block</td>
+            <td><code>52</code></td>
+            <td>Read a secified block from a MIFARE Classic device</td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>MF</mark></td>
+            <td>Set Aime key??</td>
+            <td><code>54</code></td>
+            <td>/shrug</td>
+            <td>1+</td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>55</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>60</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>61</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>MFL</mark></td>
+            <td>Reset</td>
+            <td><code>62</code></td>
+            <td>Reset the device to an initial state</td>
+            <td></td>
+            <td>0</td>
+        </tr>
+        <tr>
+            <td></td>
+            <td></td>
+            <td><code>70</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>F</mark></td>
+            <td>FeliCa communication</td>
+            <td><code>72</code></td>
+            <td>Proxy the enframed command to a present FeliCa device</td>
+            <td>Variable</td>
+            <td>Variable</td>
+        </tr>
+        <tr>
+            <td colspan="6">LED commands (address <code>08</code>)</td>
+        </tr>
+        <tr>
+            <td><mark>L</mark></td>
+            <td>Reset</td>
+            <td><code>10</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Set timeout</td>
+            <td><code>11</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Set timeout response</td>
+            <td><code>14</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>L</mark></td>
+            <td>Set LED colour</td>
+            <td><code>82</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Set LED count</td>
+            <td><code>86</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td><mark>L</mark></td>
+            <td>Get board info</td>
+            <td><code>f0</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Get board status</td>
+            <td><code>f1</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Get firmware sum</td>
+            <td><code>f2</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Get protocol version</td>
+            <td><code>f3</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+        <tr>
+            <td></td>
+            <td>Bootloader</td>
+            <td><code>fd</code></td>
+            <td></td>
+            <td></td>
+            <td></td>
+        </tr>
+    </tbody>
+</table>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/pages/sega/software/jvs.html b/templates/pages/sega/software/jvs.html
index 603aaf7..a9665bd 100644
--- a/templates/pages/sega/software/jvs.html
+++ b/templates/pages/sega/software/jvs.html
@@ -1,4 +1,115 @@
 {% extends "sega.html" %}
-{% block title %}{% endblock %}
+{% block title %}JVS{% endblock %}
 {% block body %}
+<h1>JAMMA Video Standard</h1>
+<a href="{{ROOT}}/static/JVST_VER3.pdf">A copy of the JVS standard can be found here</a>. The astute reader may observe
+it is in Japanese. A rather excelent translation can be <a href="http://daifukkat.su/files/jvs_wip.pdf">found here</a>.
+
+<p>JVS is a communication standard designed for I/O devices in arcade macines. It typically operates over RS485 serial,
+    however the framing format can and sometimes is used outside of this context.</p>
+<p>This page documents the canonical JVS structure. Some devices, notably the {{ part("838-14971")|safe }}, use a slight
+    variant on the format. <a href="./comio.html">The differences between the two formats are document here</a>.
+</p>
+
+<h2>Escaping</h2>
+<p>Every packet sent begins with the <mark>SYNC</mark> byte, <code>0xe0</code>. Read buffers should be continually
+    flushed until this
+    byte is observed.</p>
+<p>As such, <code>0xe0</code> is reserved, and is escaped. A byte is escaped using <mark>MARK</mark>, <code>0xd0</code>,
+    followed by
+    the byte's value subtract one. While any byte can be escaped, the only two that require escaping are
+    <mark>SYNC</mark> and <mark>MARK</mark>, escaped as <code>D0 DF</code> and <code>D0 CF</code> respectively. All
+    operations on packets, such as checksums and length calculation, are performed on the <b>unescaped</b> packet.
+</p>
+
+<h2 id="frame">Packet framing</h2>
+<figure>
+    <figcaption>Request packet (master->slave)</figcaption>
+    <table>
+        <tr>
+            <td>E0<sub>h</sub></td>
+            <td>Dest</td>
+            <td>n</td>
+            <td><mark>D</mark><sub>0</sub></td>
+            <td><mark>D</mark><sub>1</sub></td>
+            <td><mark>D</mark><sub>2</sub></td>
+            <td>...</td>
+            <td><mark>D</mark><sub>n-2</sub></td>
+            <td><mark>SUM</mark></td>
+        </tr>
+    </table>
+</figure>
+<figure>
+    <figcaption>Response packet (slave->master)</figcaption>
+    <table>
+        <tr>
+            <td>E0<sub>h</sub></td>
+            <td>Dest</td>
+            <td><mark>n</mark></td>
+            <td>Status</td>
+            <td><mark>D</mark><sub>0</sub></td>
+            <td><mark>D</mark><sub>1</sub></td>
+            <td><mark>D</mark><sub>2</sub></td>
+            <td>...</td>
+            <td><mark>D</mark><sub>n-3</sub></td>
+            <td><mark>SUM</mark></td>
+        </tr>
+    </table>
+</figure>
+
+<p><mark>SUM</mark> is calculated by summing all bytes in the packet, excluding <mark>SYNC</mark> and <mark>SUM</mark>
+    itself. <code>n</code> indicates the number of bytes succeeding itself. Due to the existance of the checksum,
+    <code>n=0</code> is nonsensical.
+</p>
+
+<h2 id="body">Commands and responses</h2>
+<p>A request packet may contain multiple commands within it. <code>D<sub>0</sub></code> always contains the first
+    command. It is followed by <code>m</code> bytes of data, typically a constant number per command but not always (see
+    the command reference), at which point either we have consumed <code>n-1</code> bytes and the next byte is
+    <mark>SUM</mark>, or the next byte is another command and we repeat.
+</p>
+<table>
+    <tr>
+        <td><mark>CMD</mark><sub>0</sub></td>
+        <td><mark>D</mark><sub>0,0</sub></td>
+        <td><mark>D</mark><sub>0,1</sub></td>
+        <td>...</td>
+        <td><mark>CMD</mark><sub>1</sub></td>
+        <td><mark>D</mark><sub>1,0</sub></td>
+        <td><mark>D</mark><sub>1,1</sub></td>
+        <td>...</td>
+        <td><mark>CMD</mark><sub>2</sub></td>
+        <td><mark>D</mark><sub>2,0</sub></td>
+        <td><mark>D</mark><sub>2,1</sub></td>
+        <td>...</td>
+        <td><mark>SUM</mark></td>
+    </tr>
+</table>
+<p>Response packets are structured similarly, however the <mark>CMD</mark> byte is not present, instead relying on the
+    response to be ordered exactly the same as the request. The data of each command is preceeded by a report code,
+    indicating that individual command's status. The below diagram also includes the entire-packet status byte too for
+    clarity.</p>
+<table>
+    <tr>
+        <td>Status</td>
+        <td>Report<sub>0</sub></td>
+        <td><mark>D</mark><sub>0,0</sub></td>
+        <td><mark>D</mark><sub>0,1</sub></td>
+        <td>...</td>
+        <td>Report<sub>1</sub></td>
+        <td><mark>D</mark><sub>1,0</sub></td>
+        <td><mark>D</mark><sub>1,1</sub></td>
+        <td>...</td>
+        <td>Report<sub>2</sub></td>
+        <td><mark>D</mark><sub>2,0</sub></td>
+        <td><mark>D</mark><sub>2,1</sub></td>
+        <td>...</td>
+        <td><mark>SUM</mark></td>
+    </tr>
+</table>
+
+<h2 id="commands">Individual commands</h2>
+<p>I may document these at some point in the future, but honestly the <a
+        href="http://daifukkat.su/files/jvs_wip.pdf">translated reference</a> linked at the top of this page does a
+    great job.</p>
 {% endblock %}
\ No newline at end of file