Add Power C hello example, update AGENTS index, powerc-build and graphics skill

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -3,7 +3,7 @@
 > **Assembled by a collective of 150 expert Commodore 64 developers.**
 > This file is the primary reference for AI agents assisting with Commodore 64 application development.
 > Core C64 platform knowledge is sourced from canonical reference books (see Sources below).
-> Supplemental modern emulator workflow guidance is included for **VICE 3.10** from `C:\Program Files\GTK3VICE-3.10-win64\doc\vice.txt`.
+> Supplemental modern emulator workflow guidance is included for **VICE 3.10** from the manual installed as `C:\Program Files\GTK3VICE-3.10-win64\doc\vice.pdf` (copy kept at `reference/vice.pdf`).
 
 ---
 
@@ -39,17 +39,34 @@ This repository contains structured skills and reference material for developing
 | `reference/cia-registers.md` | CIA 6526 register map |
 | `reference/disk-dos-commands.md` | 1541 DOS command reference |
 | `reference/vice-usage.md` | VICE 3.10 emulator, monitor, autostart, and automation reference |
+| `reference/vice.pdf` | VICE 3.10 manual as shipped with the emulator |
+| `reference/POWERc.d81` | Power C compiler, libraries, and headers (copy before writing to it) |
+| `reference/Power_C_Instruction_Manual.pdf` | Power C Instruction Manual (Spinnaker, 1986) |
 
 ### Example Programs
 
 | File | Description |
 |------|-------------|
 | `examples/hello-world.asm` | Minimal 6510 assembly hello world |
+| `examples/bitmap-demo.asm` | Hi-res 320×200 bitmap mode: draws a diagonal line, key returns to text mode |
 | `examples/sprite-demo.bas` | BASIC sprite programming demo |
+| `examples/sprite-music-demo.bas` | Multicolor sprite moving to a SID bass line |
 | `examples/sound-demo.bas` | SID chip sound demo in BASIC |
 | `examples/disk-access.bas` | Sequential and relative file access |
 | `examples/irq-handler.asm` | Custom IRQ handler skeleton |
 | `examples/kernal-io.asm` | Using Kernal routines for I/O |
+| `examples/moonlander.c` | Lunar Lander game in C (cc65), joystick control |
+| `examples/moonlander.prg` | Built `moonlander.c` binary |
+| `examples/moonlander-build.bat` | Build `moonlander.c` with `cl65`; `-run` also launches it |
+| `examples/run.bat` | Rebuild if needed, then autostart `moonlander.prg` in VICE |
+| `examples/linked-list-test.c` | `malloc`-backed linked list tests plus a heap capacity probe (cc65) |
+| `examples/linked-list-test.prg` | Built `linked-list-test.c` binary |
+| `examples/linked-list-test-build.bat` | Build `linked-list-test.c` with `cl65`; `-run` also launches it |
+| `examples/powerc-hello.c` | Minimal Power C program; ASCII source converted to PETSCII for the disk |
+| `examples/powerc-hello.d81` | Power C work disk with `hello.c` compiled, linked, and ready to run |
+| `examples/powerc-work.d81` | Writable working copy of the Power C system disk |
+| `examples/powerc-build.bat` | Run a Power C Shell command sequence on a work disk via `-keybuf` |
+| `examples/powerc-ced.bat` | Boot the Power C system disk and enter the `ced` editor |
 | `examples/vice-autostart-c64os.bat` | Launch `c64os.prg` directly in `x64sc` |
 | `examples/vice-monitor-c64os.txt` | VICE monitor playback script for debugging `c64os.prg` |
 | `examples/vice-debug-c64os.bat` | Launch `c64os.prg` with VICE native monitor and debug-friendly options |
@@ -194,7 +211,7 @@ This knowledge base was compiled from these canonical references:
 
 ### Supplemental Emulator Source
 
-12. **VICE 3.10 Manual** — `C:\Program Files\GTK3VICE-3.10-win64\doc\vice.txt`
+12. **VICE 3.10 Manual** — `C:\Program Files\GTK3VICE-3.10-win64\doc\vice.pdf` (copy: `reference/vice.pdf`)
    - Use for emulator operation, autostart behavior, monitor commands, snapshots, and automation interfaces
 
 ---

examples/powerc-build.bat

@@ -1,8 +1,10 @@
 @echo off
 setlocal
-REM Usage: powerc-build.bat "shell commands"   (use \n for RETURN)
+REM Usage: powerc-build.bat "shell commands" [disk.d81]   (use \n for RETURN)
 set "VICE_EXE=C:\Program Files\GTK3VICE-3.10-win64\bin\x64sc.exe"
 set "D81=%~dp0powerc-work.d81"
+REM Optional second argument selects another work disk image
+if not "%~2"=="" set "D81=%~2"
 set "CMDS=%~1"
 if "%CMDS%"=="" set "CMDS=cc squares\n"
 "%VICE_EXE%" -8 "%D81%" -autostart "%D81%:shell" -autostart-warp -warp -keybuf "%CMDS%"

examples/powerc-hello.c

@@ -0,0 +1,42 @@
+/* powerc-hello.c - first program for Power C on the C64
+ *
+ * Prints a small table and demonstrates 16-bit int wrap-around,
+ * so it exercises printf(), a counting loop and int arithmetic.
+ *
+ * Build on the Power C disk (examples/powerc-hello.d81 already holds
+ * the compiled result):
+ *
+ *   cc hello.c
+ *   link -s
+ *   > hello.o
+ *   > ^            (pull in stdlib.l + syslib.l)
+ *   >              (empty RETURN)
+ *   output file name: hello
+ *
+ * This file is plain ASCII; Power C needs PETSCII source with CR line
+ * endings, so convert it before writing it to the image:
+ *
+ *   c1541 powerc-hello.d81 -write hello.pet "hello.c,s"
+ *
+ * Then run it with -autostart "powerc-hello.d81:hello", or from BASIC:
+ *   LOAD"HELLO",8  : RUN
+ */
+
+#include <stdio.h>
+
+main()
+{
+    int i, v;
+
+    printf("power c on the c64\n");
+    printf("==================\n\n");
+
+    for (i = 1; i <= 5; i++) {
+        v = i * i;
+        printf("%d squared is %d\n", i, v);
+    }
+
+    v = 32767;
+    v = v + 1;
+    printf("\nint is 16-bit: 32767 + 1 = %d\n", v);
+}

skills/graphics-vic2/SKILL.md

@@ -119,14 +119,14 @@ Bit 0     (unused)
 ```
 
 Video matrix address = bits[7:4] × $0400 within the VIC-II bank
-Character base = bits[3:1] × $0800 within the VIC-II bank
+Character base = bits[3:1] × $0800 within the VIC-II bank (bit 0 is unused)
 
 | $D018 Value | Screen RAM | Character Set |
 |-------------|------------|---------------|
-| $10 (default) | $0400 | $1000 (ROM chars via mirror) |
-| $14 | $0400 | $1800 (ROM chars, inverted) |
-| $18 | $0400 | $2000 (user char at $2000) |
-| $15 | $0400 | $1400 (user chars at $1400 in Bank 0) |
+| $15 (default) | $0400 | $1000 (character ROM via mirror) |
+| $17 | $0400 | $1800 (upper half of character ROM, reversed chars) |
+| $18 | $0400 | $2000 (user charset at $2000) |
+| $10 | $0400 | $0000 (RAM, not the character ROM) |
 
 ---
 
@@ -153,7 +153,7 @@ Character base = bits[3:1] × $0800 within the VIC-II bank
 - Each 8×8 cell has its own 2-color pair stored in screen RAM
 - Bitmap data location: bit 3 of $D018 × $2000 within VIC-II bank
   - $D018 = $18 → bitmap at $2000 (if screen at $0400)
-  - $D018 = $1A → bitmap at $4000 in Bank 0? No — bitmap bit is bit3 of high nybble
+  - $D018 = $08 → bitmap at $0000; in bitmap mode only bit 3 matters, so $1A and $3A also give $2000
 - Screen RAM holds color pairs: high nybble = "0" pixel color, low nybble = "1" pixel color
 
 ### 5. Multicolor Bitmap Mode ($D011 bit 5 = 1, $D016 bit 4 = 1)