diff --git a/doc/notes.txt b/doc/notes.txt
index 40b55f56..502cd8fd 100644
--- a/doc/notes.txt
+++ b/doc/notes.txt
@@ -197,6 +197,7 @@ TODO:
   - emu doesn't reset properly (after gotoxy() BIOS call)
   - disk image support
   - https://github.com/cc65/cc65/issues/946
+  - sample buffer skips
 
 
 WEB WORKER FORMAT
@@ -395,3 +396,13 @@ Markdown (showdown) interface
 - cursor shows current state/errors (must map markdown->src lines)
 - show preview emulator at each step (play button? run when viewed?)
 
+
+DOCUMENTATION
+
+memory map
+BIOS routines
+cc65 standard libs
+cc65 headers
+example headers (presets/*/*.h)
+libcv headers (src/worker/lib)
+ASM includes
diff --git a/index.html b/index.html
index 99ad439b..923881e9 100644
--- a/index.html
+++ b/index.html
@@ -300,7 +300,7 @@ if (window.location.host.endsWith('8bitworkshop.com')) {
       <div id="javatari-console-panel" style="margin: 0 auto; box-shadow: 2px 2px 10px rgb(60, 60, 60);"></div>
     </div>
     <!-- control instructions -->
-    <div class="emucontrols-vcs text-center small control-insns" style="display:none">
+    <div class="emucontrols-vcs emucontrols-c64 text-center small control-insns" style="display:none">
       <span class="control-def"><span class="control-key">&#x2190;&#x2191;&#x2193;&#x2192;</span> Joystick</span>
       <span class="control-def"><span class="control-key small">Space</span> Button</span>
     </div>
diff --git a/presets/c64/siegegame.c b/presets/c64/siegegame.c
index bb2b8b81..8ab98d55 100644
--- a/presets/c64/siegegame.c
+++ b/presets/c64/siegegame.c
@@ -18,8 +18,6 @@ typedef unsigned short word;
 static byte** BASL = (byte**) 0xD1;
 
 byte getchar(byte x, byte y) {
-  // JSR VTABZ
-  // LDA (BASL) ($28)
   gotoxy(x,y);		// set cursor position
   return (*BASL)[x];	// lookup value @ cursor address
 }
@@ -183,8 +181,11 @@ void make_move() {
   ai_control(&players[0]);
   ai_control(&players[1]);
   // if players collide, 2nd player gets the point
+  textcolor(COLOR_CYAN);
   move_player(&players[1]);
+  textcolor(COLOR_YELLOW);
   move_player(&players[0]);
+  textcolor(COLOR_WHITE);
 }
 
 void declare_winner(byte winner) {
@@ -204,6 +205,7 @@ void declare_winner(byte winner) {
 void play_round() {
   reset_players();
   clrscr();
+  textcolor(COLOR_WHITE);
   draw_playfield();
   while (1) {
     make_move();
diff --git a/src/machine/c64.ts b/src/machine/c64.ts
index 8d5ab187..0b5219af 100644
--- a/src/machine/c64.ts
+++ b/src/machine/c64.ts
@@ -10,6 +10,8 @@ import { lzgmini, stringToByteArray, hex, rgb2bgr } from "../common/util";
 // http://sta.c64.org/cbm64mem.html
 // http://hitmen.c02.at/temp/palstuff/
 
+// native JS emulator (NOT USED)
+
 const KEYBOARD_ROW_0 = 0;
 const SWCHA = 8;
 const SWCHB = 9;
@@ -594,7 +596,7 @@ export class C64_WASMMachine extends BaseWASMMachine implements Machine {
   }
   advanceFrame(trap: TrapCondition) : number {
     this.typeInitString(); // type init string into console (TODO: doesnt work during debug)
-    return super.advanceFrameClock(trap, 19656); // TODO: NTSC?
+    return super.advanceFrameClock(trap, 19656); // TODO: 985248 / 50 = 19705? music skips
   }
   typeInitString() {
     if (this.initstring) {
diff --git a/src/platform/c64.ts b/src/platform/c64.ts
index 310abf3c..cb0ab57d 100644
--- a/src/platform/c64.ts
+++ b/src/platform/c64.ts
@@ -17,6 +17,7 @@ const C64_PRESETS = [
   {id:'scroll4.c', name:'Scrolling 4 (C)'},
   {id:'scroll5.c', name:'Scrolling 5 (C)'},
   {id:'climber.c', name:'Climber Game (C)'},
+  {id:'musicplayer.c', name:'Music Player (C)'},
 ];
 
 const C64_MEMORY_MAP = { main:[
@@ -26,12 +27,16 @@ const C64_MEMORY_MAP = { main:[
   {name:'BASIC ROM',    start:0xa000,size:0x2000,type:'rom'},
   {name:'RAM',          start:0xc000,size:0x1000,type:'ram'},
   {name:'VIC-II I/O',   start:0xd000,size:0x0400,type:'io'},
+  {name:'SID',          start:0xd400,size:0x0400,type:'io'},
   {name:'Color RAM',    start:0xd800,size:0x0400,type:'io'},
   {name:'CIA 1',        start:0xdc00,size:0x0100,type:'io'},
   {name:'CIA 2',        start:0xdd00,size:0x0100,type:'io'},
+  {name:'I/O 1',        start:0xde00,size:0x0100,type:'io'},
+  {name:'I/O 2',        start:0xdf00,size:0x0100,type:'io'},
   {name:'KERNAL ROM',   start:0xe000,size:0x2000,type:'rom'},
 ] }
 
+// native C64 platform (NOT USED)
 class C64Platform extends Base6502MachinePlatform<C64> implements Platform {
 
   newMachine()          { return new C64(); }
@@ -42,6 +47,7 @@ class C64Platform extends Base6502MachinePlatform<C64> implements Platform {
   getMemoryMap()        { return C64_MEMORY_MAP; }
 }
 
+// WASM C64 platform
 class C64WASMPlatform extends Base6502MachinePlatform<C64_WASMMachine> implements Platform {
 
   newMachine()          { return new C64_WASMMachine('c64'); }
@@ -55,6 +61,9 @@ class C64WASMPlatform extends Base6502MachinePlatform<C64_WASMMachine> implement
   getDefaultExtension() { return ".c"; };
   readAddress(a)        { return this.machine.readConst(a); }
   getMemoryMap()        { return C64_MEMORY_MAP; }
+  showHelp() {
+    window.open("https://sta.c64.org/cbm64mem.html", "_help");
+  }
 }
 
 PLATFORMS['c64'] = C64WASMPlatform;