Reformat Specifications table (#338)

* Reformat Specifications table

Fixes #332

* Replace "model" with "revision" where relevant

* Change "RGB555" to "15-bit RGB"

As per #338 (comment)

Author: ISSOtm

src/Specifications.md

@@ -1,17 +1,71 @@
 # Specifications
 
-        | Game Boy                       | Game Boy Pocket | Game Boy Color  | Super Game Boy |
-----------------|--------------------------------|-----------------|-----------------|----------------|
-CPU             | 8-bit Sharp LR35902            |                 |                 |                |
-Clock           | 4.194304 MHz                   |                 | 8.388608 MHz    | 4.295454MHz (SGB1, NTSC)|
-Work RAM        | 8 KB                           |                 | 32 KB           |                |
-Video RAM       | 8 KB                           |                 | 16 KB           |                |
-Screen Size     | LCD 4,7 x 4,3 cm               | LCD 4,8 x 4,4 cm| TFT 4,4 x 4 cm  |                |
-Resolution      | 160x144                        |                 |                 | 256x224 (including border)|
-Sprites         | Max 40 per screen, 10 per line |                 |                 |                |
-Palettes        | 1x4 BG, 2x3 OBJ                |                 | 8x4 BG, 8x3 OBJ | 1+4x3, 4x15 (border) |
-Colors          | 4 grayshades                   |                 | 32768 colors    |                |
-Horizontal Sync | 9.198 KHz                      |                 |                 | 9.41986 KHz    |
-Vertical Sync   | 59.73 Hz                       |                 |                 | 61.1679 Hz     |
-Sound           | 4 channels with stereo sound   |                 |                 |                |
-Power           | DC6V 0.7W                      | DC3V 0.7W       | DC3V 0.6W       |                |
+<style>
+td {
+    text-align: center;
+}
+td:first-child {
+    text-align: left;
+}
+</style>
+
+<table>
+  <thead>
+    <tr>
+      <th></th><th>Game Boy (DMG)</th><th>Game Boy Pocket (MGB)</th><th>Super Game Boy (SGB)</th><th>Game Boy Color (CGB)</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>CPU</td><td colspan="4">8-bit 8080-like Sharp CPU (speculated to be a SM83 core)</td>
+    </tr>
+    <tr>
+      <td>CPU freq</td><td colspan="2">4.194304&nbsp;MHz</td><td>Depends on revision<sup class="footnote-reference"><a href="#sgb_clk">1</a></sup></td><td>Up to 8.388608&nbsp;MHz</td>
+    </tr>
+    <tr>
+        <td>Work RAM</td><td colspan="3">8&nbsp;KiB</td><td>32&nbsp;KiB<sup class="footnote-reference"><a href="#compat">2</a></sup> (4&nbsp;+&nbsp;7&nbsp;×&nbsp;4&nbsp;KiB)</td>
+    </tr>
+    <tr>
+        <td>Video RAM</td><td colspan="3">8&nbsp;KiB</td><td>16&nbsp;KiB<sup class="footnote-reference"><a href="#compat">2</a></sup> (2&nbsp;×&nbsp;8&nbsp;KiB)</td>
+    </tr>
+    <tr>
+        <td>Screen</td><td>LCD 4.7&nbsp;×&nbsp;4.3&nbsp;cm</td><td>LCD 4.8&nbsp;×&nbsp;4.4&nbsp;cm</td><td>CRT TV</td><td>TFT 4.4&nbsp;×&nbsp;4&nbsp;cm</td>
+    </tr>
+    <tr>
+        <td>Resolution</td><td colspan="2">160&nbsp;×&nbsp;144</td><td>160&nbsp;×&nbsp;144 within 256&nbsp;×&nbsp;224 border</td><td>160&nbsp;×&nbsp;144</td>
+    </tr>
+    <tr>
+        <td>OBJ ("sprites")</td><td colspan="4">8&nbsp;×&nbsp;8 or 8&nbsp;×16 ; max 40 per screen, 10 per line</td>
+    </tr>
+    <tr>
+        <td>Palettes</td><td colspan="2">BG: 1&nbsp;×&nbsp;4, OBJ: 2&nbsp;×&nbsp;3</td><td>BG/OBJ: 1&nbsp;+&nbsp;4&nbsp;×&nbsp;3, border: 4&nbsp;×&nbsp;15</td><td>BG: 8&nbsp;×&nbsp;4, OBJ: 8&nbsp;×&nbsp;3<sup class="footnote-reference"><a href="#compat">2</a></sup></td>
+    </tr>
+    <tr>
+        <td>Colors</td><td>4 shades of green</td><td>4 shades of gray</td><td colspan="2">32768 colors (15-bit RGB)</td>
+    </tr>
+    <tr>
+        <td>Horizontal sync</td><td colspan="2">9.198&nbsp;KHz</td><td>Complicated<sup class="footnote-reference"><a href="#sgb_vid">3</a></sup></td><td>9.198&nbsp;KHz</td>
+    </tr>
+    <tr>
+        <td>Vertical sync</td><td colspan="2">59.73&nbsp;Hz</td><td>Complicated<sup class="footnote-reference"><a href="#sgb_vid">3</a></sup></td><td>59.73&nbsp;Hz</td>
+    </tr>
+    <tr>
+        <td>Sound</td><td colspan="2">4 channels with stereo output</td><td>4 GB channels + SNES audio</td><td>4 channels with stereo output</td>
+    </tr>
+    <tr>
+        <td>Power</td><td>DC 6V, 0.7&nbsp;W</td><td>DC 3V, 0.7&nbsp;W</td><td>Powered by SNES</td><td>DC 3V, 0.6&nbsp;W</td>
+    </tr>
+  </tbody>
+</table>
+
+[^sgb_clk]:
+SGB1 cartridges derive the GB CPU clock from the SNES' clock, [yielding a clock speed a bit higher](<#SGB System Clock>), which differs slightly between NTSC and PAL systems.
+SGB2 instead uses a clock internal to the cartridge, and so has the same speed as the handhelds.
+
+[^compat]:
+The same value as on DMG is used in compatibility mode.
+
+[^sgb_vid]:
+The SGB runs two consoles: a Game Boy within the SGB cartridge, and the SNES itself.
+The GB LCD output is captured and displayed by the SNES, but the two consoles' frame rates don't quite sync up, leading to duplicated and/or dropped frames.
+The GB side of the vertical sync depends on the CPU clock[^sgb_clk], with the same ratio as the handhelds.