PRG: add OVAL/RING BASIC commands, update KERNAL doc (#219)

* PRG: add OVAL/RING BASIC commands, update KERNAL doc

* minor changes

Author: mooinglemur

.github/workflows/build.yml

@@ -44,6 +44,8 @@ jobs:
           "X16 Reference - Appendix B - VERA Recovery.md" \
           "X16 Reference - Appendix C - 65C02 Processor.md" \
           "X16 Reference - Appendix D - Official Expansion Cards.md" \
+          "X16 Reference - Appendix E - Diagnostic Bank.md" \
+          "X16 Reference - Appendix F - 65C816 Processor.md" \
           | md-to-pdf --config-file .gh/config.js --stylesheet .gh/markdown.css > "artifacts/Commander X16 Programmer's Reference Guide.pdf"
       - uses: actions/upload-artifact@v4
         with:

X16 Reference - 04 - BASIC.md

@@ -95,6 +95,7 @@ for GitHub's Markdown flavor. Do not remove!
 | `ON` | command | A GOTO/GOSUB table based on a variable value | C64 |
 | `OPEN` | command | Opens a logical file to disk or other device | C64 |
 | `OR` | operator | Bitwise or boolean "OR" | C64 |
+| [`OVAL`](#oval) | command | Draws a filled oval in graphics mode | X16 |
 | `PEEK` | function | Returns a value from a memory address | C64 |
 | `π` | function | Returns the constant for the value of pi | C64 |
 | [`POINTER`](#pointer) | function | Returns the address of a BASIC variable | C128 |
@@ -121,6 +122,7 @@ for GitHub's Markdown flavor. Do not remove!
 | [`RESTORE`](#restore) | command | Resets the `READ` pointer to a `DATA` constant | C64 |
 | `RETURN` | command | Returns from a subroutine to the statement following a GOSUB | C64 |
 | `RIGHT$` | function | Returns a substring from the end of a string | C64 |
+| [`RING`](#ring) | command | Draws an oval outline in graphics mode | X16 |
 | `RND` | function | Returns a floating point number 0 <= n < 1 | C64 |
 | [`RPT$`](#rpt) | function | Returns a string of repeated characters | X16 |
 | `RUN` | command | Clears the variable state and starts a BASIC program | C64 |
@@ -1031,6 +1033,23 @@ moved away from the user, and positive if it is moved towards the user. The rang
 OLD
 ```
 
+### OVAL
+
+**TYPE: Command**  
+**FORMAT: OVAL &lt;x1&gt;,&lt;y1&gt;,&lt;x2&gt;,&lt;y2&gt;,&lt;color&gt;**
+
+**Action:** This command draws a filled oval on the graphics screen in a given color.
+
+The coordinate arguments define the rectangular bounding box of the oval. To draw a filled circle, make the width and height equal to each other.
+
+**EXAMPLE of OVAL Statement:**
+
+```BASIC
+10 SCREEN $80
+20 FORI=1 TO 20:OVAL RND(1)*320,RND(1)*200,RND(1)*320,RND(1)*200,RND(1)*128:NEXT
+30 GOTO 20
+```
+
 ### POINTER
 
 **TYPE: Function**  
@@ -1219,6 +1238,23 @@ The full set of macros is documented [here](X16%20Reference%20-%20Appendix%20A%2
 
 This example plays a chromatic scale while applying pulse-width modulation on the voice.
 
+### RING
+
+**TYPE: Command**  
+**FORMAT: RING &lt;x1&gt;,&lt;y1&gt;,&lt;x2&gt;,&lt;y2&gt;,&lt;color&gt;**
+
+**Action:** This command draws an oval outline on the graphics screen in a given color.
+
+The coordinate arguments define the rectangular bounding box of the oval. To draw a circle outline, make the width and height equal to each other.
+
+**EXAMPLE of RING Statement:**
+
+```BASIC
+10 SCREEN $80
+20 FORI=1 TO 20:RING RND(1)*320,RND(1)*200,RND(1)*320,RND(1)*200,RND(1)*128:NEXT
+30 GOTO 20
+```
+
 ### RECT
 
 **TYPE: Command**  

X16 Reference - 05 - KERNAL.md

@@ -131,7 +131,7 @@ The 16 bit ABI generally follows the following conventions:
 | [`GRAPH_clear`](#function-name-graph_clear) | `$FF23` | Video | Clear screen | none | r0 r1 r2 r3 A X Y P | X16
 | [`GRAPH_draw_image`](#function-name-graph_draw_image) | `$FF38` | Video | Draw a rectangular image | r0 r1 r2 r3 r4 | A P | X16
 | [`GRAPH_draw_line`](#function-name-graph_draw_line) | `$FF2C` | Video | Draw a line | r0 r1 r2 r3 | r0 r1 r2 r3 r7 r8 r9 r10 r12 r13 A X Y P | X16
-| [`GRAPH_draw_oval`](#function-name-graph_draw_oval) 🚫 | `$FF35` | Video | Draw an oval or circle | - | - | X16
+| [`GRAPH_draw_oval`](#function-name-graph_draw_oval) | `$FF35` | Video | Draw an oval or circle (optionally filled) | r0 r1 r2 r3 r4 C | A X Y P | X16
 | [`GRAPH_draw_rect`](#function-name-graph_draw_rect) † | `$FF2F` | Video | Draw a rectangle (optionally filled) | r0 r1 r2 r3 r4 C | A P | X16
 | [`GRAPH_get_char_size`](#function-name-graph_get_char_size) | `$FF3E` | Video | Get size and baseline of a character | A X | A X Y P | X16
 | [`GRAPH_init`](#function-name-graph_init) | `$FF20` | Video | Initialize graphics | r0 | r0 r1 r2 r3 A X Y P | X16