From 1e44d055361394cf2b3c8184ec6314463ca41e54 Mon Sep 17 00:00:00 2001
From: Steven Hugg <hugg@fasterlight.com>
Date: Sun, 10 Mar 2019 12:17:12 -0400
Subject: [PATCH] nes: updated presets

---
 doc/notes.txt              |  3 +-
 presets/nes/attributes.c   | 33 ++++++----------
 presets/nes/climbr_title.s | 79 ++++++++++++++++++++++++++++++++++++++
 presets/nes/ex4.asm        | 37 +++++++++---------
 presets/nes/hello.c        | 64 ++++++++++++------------------
 presets/nes/neslib1.c      | 34 ----------------
 presets/nes/neslib5.c      | 55 --------------------------
 presets/nes/nesppu.asm     | 21 +++++-----
 presets/nes/ppuhello.c     | 48 +++++++++++++++++++++++
 presets/nes/rletitle.c     | 49 +++++++++++++++++++++++
 presets/nes/siegegame.c    | 10 +++--
 presets/nes/vrambuf.c      |  2 +-
 presets/nes/vrambuf.h      | 12 ++++--
 presets/nes/vrambuffer.c   |  2 +-
 src/platform/nes.ts        |  5 ++-
 src/ui.ts                  |  1 +
 tss                        |  2 +-
 17 files changed, 265 insertions(+), 192 deletions(-)
 create mode 100644 presets/nes/climbr_title.s
 delete mode 100644 presets/nes/neslib1.c
 delete mode 100644 presets/nes/neslib5.c
 create mode 100644 presets/nes/ppuhello.c
 create mode 100644 presets/nes/rletitle.c

diff --git a/doc/notes.txt b/doc/notes.txt
index e47d9a06..c1c79489 100644
--- a/doc/notes.txt
+++ b/doc/notes.txt
@@ -97,7 +97,8 @@ TODO:
 - NES: disassembly not aligned on PC
 - NES: vrambuf.c for Solarian
 - game starts even if switched away before first load
-
+- vcs: break on # of lines changed (maybe using getRasterPosition?)
+- profiler restarts when paused
 
 WEB WORKER FORMAT
 
diff --git a/presets/nes/attributes.c b/presets/nes/attributes.c
index 639c7bf8..d9251d08 100644
--- a/presets/nes/attributes.c
+++ b/presets/nes/attributes.c
@@ -3,19 +3,15 @@
 #include <string.h>
 #include <stdlib.h>
 
-// link the pattern table into PRG ROM
-// we'll write it into CHR RAM on startup
+// link the pattern table into CHR ROM
+//#link "chr_generic.s"
 
-//#link "jroatch.c"
-extern unsigned char jroatch_chr[0x1000];
-#define PATTERN_TABLE jroatch_chr
-
-// palette for balls, there are four sets for different ball colors
-const unsigned char bg_palette[16]={/*{pal:"nes",n:4,sets:4}*/
-  0x0f,0x17,0x27,0x37,
-  0x0f,0x11,0x21,0x31,
-  0x0f,0x15,0x25,0x35,
-  0x0f,0x19,0x29,0x39
+const char PALETTE[16] = {
+  0x03,
+  0x11,0x30,0x27, 0,
+  0x1c,0x20,0x2c, 0,
+  0x00,0x10,0x20, 0,
+  0x06,0x16,0x26
 };
 
 // convert nametable address to attribute address
@@ -63,7 +59,8 @@ void color_demo(void) {
   while (1) {
     char x = rand() & 0x3f;
     char y = rand() & 0x3f;
-    put_pixel(x, y, 2);
+    char color = rand() & 3;
+    put_pixel(x, y, color);
     // reset scroll position
     vram_adr(0);
   }
@@ -94,16 +91,8 @@ void color_demo1(void) {
 
 // main function, run after console reset
 void main(void) {
-  // copy pattern table to PRG RAM
-  vram_adr(0x0);
-  vram_write((unsigned char*)PATTERN_TABLE, sizeof(PATTERN_TABLE));
-
-  // clear name tables
-  vram_adr(0x2000);
-  vram_fill(0, 0x800);
-
   // set palette colors
-  pal_bg(bg_palette);
+  pal_bg(PALETTE);
 
   // enable PPU rendering (turn on screen)
   ppu_on_all();
diff --git a/presets/nes/climbr_title.s b/presets/nes/climbr_title.s
new file mode 100644
index 00000000..94941dcb
--- /dev/null
+++ b/presets/nes/climbr_title.s
@@ -0,0 +1,79 @@
+.export _climbr_title_pal
+.export _climbr_title_rle
+
+_climbr_title_pal:
+ .byte $0f,$11,$25,$35,$0f,$01,$21,$30
+ .byte $0f,$06,$1c,$3c,$0f,$11,$28,$38
+_climbr_title_rle:
+ .byte $01,$00,$01,$10,$80,$01,$02,$00
+ .byte $80,$00,$80,$00,$01,$1f,$80,$80
+ .byte $00,$01,$07,$41,$4e,$00,$38,$42
+ .byte $49,$54,$57,$4f,$52,$4b,$53,$48
+ .byte $4f,$50,$00,$47,$41,$4d,$45,$00
+ .byte $01,$02,$80,$00,$01,$1d,$7f,$7f
+ .byte $80,$00,$01,$1c,$8f,$7f,$80,$00
+ .byte $01,$06,$80,$01,$0b,$00,$01,$09
+ .byte $80,$8f,$80,$00,$01,$09,$7f,$01
+ .byte $02,$80,$01,$02,$7f,$7f,$80,$01
+ .byte $02,$00,$ba,$bb,$00,$01,$02,$80
+ .byte $00,$8f,$80,$01,$03,$00,$80,$80
+ .byte $00,$01,$03,$7f,$7f,$8f,$8f,$7f
+ .byte $7f,$80,$7f,$7f,$80,$01,$03,$be
+ .byte $bf,$80,$00,$00,$80,$01,$04,$00
+ .byte $80,$01,$03,$00,$01,$02,$7f,$7f
+ .byte $8f,$80,$80,$8f,$8f,$00,$7f,$7f
+ .byte $80,$7f,$7f,$80,$7f,$7f,$80,$7f
+ .byte $00,$7f,$00,$80,$80,$7f,$7f,$80
+ .byte $7f,$00,$80,$00,$00,$7f,$01,$02
+ .byte $80,$01,$02,$00,$01,$02,$7f,$7f
+ .byte $80,$8f,$8f,$80,$7f,$01,$06,$80
+ .byte $80,$7f,$01,$02,$8f,$80,$80,$00
+ .byte $00,$7f,$01,$02,$80,$01,$02,$00
+ .byte $01,$02,$7f,$7f,$80,$80,$00,$80
+ .byte $7f,$7f,$8f,$7f,$8f,$7f,$7f,$80
+ .byte $80,$7f,$7f,$8f,$80,$80,$00,$01
+ .byte $02,$7f,$01,$02,$80,$01,$02,$00
+ .byte $01,$02,$7f,$7f,$80,$7f,$7f,$80
+ .byte $7f,$7f,$80,$7f,$80,$7f,$7f,$80
+ .byte $80,$7f,$7f,$80,$01,$02,$00,$01
+ .byte $02,$7f,$01,$02,$80,$01,$02,$00
+ .byte $01,$02,$7f,$7f,$80,$7f,$7f,$80
+ .byte $7f,$7f,$80,$7f,$80,$7f,$7f,$80
+ .byte $80,$7f,$7f,$80,$80,$00,$01,$03
+ .byte $7f,$01,$02,$00,$80,$01,$04,$7f
+ .byte $7f,$80,$7f,$7f,$80,$7f,$7f,$80
+ .byte $7f,$80,$7f,$7f,$80,$80,$7f,$7f
+ .byte $80,$80,$00,$01,$03,$8f,$7f,$7f
+ .byte $00,$80,$01,$04,$7f,$7f,$80,$7f
+ .byte $7f,$80,$7f,$7f,$80,$7f,$80,$7f
+ .byte $7f,$80,$80,$7f,$7f,$80,$80,$00
+ .byte $01,$04,$8f,$7f,$7f,$00,$00,$7f
+ .byte $7f,$80,$8f,$8f,$80,$8f,$8f,$80
+ .byte $8f,$8f,$80,$8f,$00,$8f,$8f,$80
+ .byte $00,$8f,$8f,$80,$80,$00,$01,$05
+ .byte $8f,$7f,$01,$03,$8f,$00,$01,$05
+ .byte $90,$80,$80,$00,$80,$00,$80,$00
+ .byte $00,$80,$01,$02,$00,$80,$00,$01
+ .byte $06,$8f,$01,$03,$00,$01,$02,$a1
+ .byte $01,$13,$00,$01,$0a,$ac,$a1,$01
+ .byte $13,$00,$01,$09,$ac,$ac,$20,$01
+ .byte $03,$00,$01,$18,$ac,$ac,$00,$06
+ .byte $01,$12,$00,$01,$08,$ac,$ac,$00
+ .byte $00,$06,$00,$01,$10,$06,$00,$01
+ .byte $07,$ac,$ac,$00,$01,$02,$06,$00
+ .byte $1f,$00,$50,$52,$45,$53,$53,$00
+ .byte $53,$54,$41,$52,$54,$00,$1e,$00
+ .byte $06,$00,$01,$06,$ac,$ac,$00,$01
+ .byte $03,$06,$00,$01,$10,$06,$00,$01
+ .byte $05,$ac,$ac,$00,$01,$04,$06,$01
+ .byte $12,$00,$01,$04,$ac,$ac,$00,$01
+ .byte $1c,$ac,$ac,$00,$01,$1c,$ac,$ac
+ .byte $00,$01,$1c,$ac,$ac,$00,$01,$1c
+ .byte $ac,$ac,$00,$01,$1d,$80,$a0,$01
+ .byte $03,$20,$00,$01,$02,$a0,$20,$00
+ .byte $f0,$00,$01,$02,$88,$22,$02,$00
+ .byte $01,$04,$88,$22,$20,$00,$01,$05
+ .byte $0a,$02,$00,$01,$07,$d5,$55,$01
+ .byte $02,$75,$00,$01,$02,$55,$01,$04
+ .byte $00,$01,$02,$05,$01,$03,$05,$01
+ .byte $00
diff --git a/presets/nes/ex4.asm b/presets/nes/ex4.asm
index 14f1b748..cd1efc13 100644
--- a/presets/nes/ex4.asm
+++ b/presets/nes/ex4.asm
@@ -69,34 +69,33 @@ SetPalette: subroutine
 ;;;;; INTERRUPT HANDLERS
 
 NMIHandler:
-	SAVE_REGS
+	SAVE_REGS	; save registers
 ; update scroll position (must be done after VRAM updates)
-	jsr ReadJoypad
-        pha
-        and #$03
-        tay
-        lda ScrollDirTab,y
+	jsr ReadJoypad0	; read first controller
+        pha		; push joypad bitmask
+        and #$03	; only keep first 2 bits
+        tay		; A -> Y
+        lda ScrollDirTab,y	; lookup table
         clc
-        adc ScrollX
-        sta ScrollX
-        sta PPU_SCROLL
-        pla
+        adc ScrollX	; A = A + ScrollX
+        sta ScrollX	; -> ScrollX
+        sta PPU_SCROLL	; -> first scroll byte
+        pla		; pop joypad bitmask
         lsr
         lsr
-        and #$03
-        tay
-        lda ScrollDirTab,y
+        and #$03	; take next two bits
+        tay		
+        lda ScrollDirTab,y ; do another lookup
         clc
-        adc ScrollY
-        sta ScrollY
-        sta PPU_SCROLL
-; reload registers
-        RESTORE_REGS
+        adc ScrollY	; A = A + ScrollY
+        sta ScrollY	; -> ScrollY
+        sta PPU_SCROLL	; -> second scroll byte
+        RESTORE_REGS	; restore registers
 	rti
 
 ; Scroll direction lookup table
 ScrollDirTab:
-	hex 00 01 ff 00
+	hex 00 01 ff 00	; 0,1,-1,0
  
 ;;;;; CONSTANT DATA
 
diff --git a/presets/nes/hello.c b/presets/nes/hello.c
index eb42215f..8f6e14b8 100644
--- a/presets/nes/hello.c
+++ b/presets/nes/hello.c
@@ -1,48 +1,34 @@
 
-#include <nes.h>
+#include "neslib.h"
+#include <string.h>
 
-const unsigned char TEXT[]="Hello PPU!!!!";
+// link the pattern table into CHR ROM
+//#link "chr_generic.s"
 
-const unsigned char PALETTE[]={0x1, 0x00, 0x10, 0x20}; // blue, gray, lt gray, white
+// function to write a string into the name table
+//   adr = start address in name table
+//   str = pointer to string
+void put_str(unsigned int adr, const char *str) {
+  vram_adr(adr);        // set PPU read/write address
+  vram_write(str, strlen(str)); // write bytes to PPU
+}
 
-void main (void) {
-  unsigned char index; // used in 'for' loops
+// main function, run after console reset
+void main(void) {
+  // set palette colors
+  pal_col(1,0x04);
+  pal_col(2,0x20);
+  pal_col(3,0x30);
 
-  // if we've just powered on,
-  // wait for PPU to warm-up
-  waitvsync();
-  waitvsync();
+  // write text to name table
+  put_str(NTADR_A(2,2),"HELLO, WORLD!");
+  put_str(NTADR_A(2,4),"THIS CODE PRINTS SOME TEXT");
+  put_str(NTADR_A(2,5),"USING ASCII-ENCODED CHARACTER");
+  put_str(NTADR_A(2,6),"SET WITH CAPITAL LETTERS ONLY");
 
-  // turn off screen
-  PPU.control = 0x0; // NMI off
-  PPU.mask = 0x0; // screen off
-
-  // load the palette
-  // set PPU address to 0x3f00
-  PPU.vram.address = 0x3f;
-  PPU.vram.address = 0x00;
-  for (index = 0; index < sizeof(PALETTE); index++) {
-    PPU.vram.data = PALETTE[index];
-  }
-
-  // load the text into VRAM
-  // set PPU address to 0x21c9
-  PPU.vram.address = 0x21;
-  PPU.vram.address = 0xc9;
-  for (index = 0; index < sizeof(TEXT); index++) {
-    PPU.vram.data = TEXT[index];
-  }
-
-  // reset the scroll position to 0
-  PPU.scroll = 0;
-  PPU.scroll = 0;
-  // reset the PPU address to 0x2000 (frame start)
-  PPU.vram.address = 0x20;
-  PPU.vram.address = 0x00;
- 
-  // turn on the screen
-  PPU.mask = 0x1e;
+  // enable PPU rendering (turn on screen)
+  ppu_on_all();
 
   // infinite loop
-  while (1);
+  while (1) ;
 }
diff --git a/presets/nes/neslib1.c b/presets/nes/neslib1.c
deleted file mode 100644
index 8f6e14b8..00000000
--- a/presets/nes/neslib1.c
+++ /dev/null
@@ -1,34 +0,0 @@
-
-#include "neslib.h"
-#include <string.h>
-
-// link the pattern table into CHR ROM
-//#link "chr_generic.s"
-
-// function to write a string into the name table
-//   adr = start address in name table
-//   str = pointer to string
-void put_str(unsigned int adr, const char *str) {
-  vram_adr(adr);        // set PPU read/write address
-  vram_write(str, strlen(str)); // write bytes to PPU
-}
-
-// main function, run after console reset
-void main(void) {
-  // set palette colors
-  pal_col(1,0x04);
-  pal_col(2,0x20);
-  pal_col(3,0x30);
-
-  // write text to name table
-  put_str(NTADR_A(2,2),"HELLO, WORLD!");
-  put_str(NTADR_A(2,4),"THIS CODE PRINTS SOME TEXT");
-  put_str(NTADR_A(2,5),"USING ASCII-ENCODED CHARACTER");
-  put_str(NTADR_A(2,6),"SET WITH CAPITAL LETTERS ONLY");
-
-  // enable PPU rendering (turn on screen)
-  ppu_on_all();
-
-  // infinite loop
-  while (1) ;
-}
diff --git a/presets/nes/neslib5.c b/presets/nes/neslib5.c
deleted file mode 100644
index f6d428f6..00000000
--- a/presets/nes/neslib5.c
+++ /dev/null
@@ -1,55 +0,0 @@
-
-//this example code unpacks a RLE'd nametable into the VRAM
-//you can create the source data using NES Screen Tool
-
-#include "neslib.h"
-
-const unsigned char test[308]={
-0x01,0x00,0x01,0xa3,0x10,0x01,0x04,0x00,0x10,0x01,0x04,0x00,0x10,0x01,0x04,0x00,
-0x10,0x01,0x04,0x00,0x01,0x0a,0x10,0x00,0x01,0x02,0x10,0x00,0x01,0x04,0x10,0x00,
-0x01,0x06,0x10,0x00,0x01,0x0c,0x10,0x00,0x01,0x02,0x10,0x01,0x02,0x00,0x01,0x02,
-0x10,0x01,0x04,0x00,0x01,0x02,0x10,0x00,0x01,0x0c,0x10,0x00,0x01,0x02,0x10,0x00,
-0x01,0x08,0x10,0x00,0x01,0x02,0x10,0x00,0x01,0x0c,0x10,0x00,0x01,0x02,0x10,0x01,
-0x04,0x00,0x10,0x01,0x04,0x00,0x01,0x02,0x10,0x00,0x01,0x42,0x10,0x00,0x01,0x06,
-0x10,0x01,0x04,0x00,0x10,0x00,0x01,0x04,0x10,0x01,0x04,0x00,0x10,0x00,0x01,0x04,
-0x10,0x00,0x01,0x06,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x00,0x01,0x04,0x10,0x00,
-0x01,0x06,0x10,0x01,0x04,0x00,0x01,0x06,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x00,
-0x01,0x04,0x10,0x01,0x02,0x00,0x01,0x04,0x10,0x00,0x01,0x02,0x10,0x00,0x01,0x06,
-0x10,0x01,0x03,0x00,0x00,0x10,0x00,0x01,0x04,0x10,0x00,0x01,0x06,0x10,0x00,0x01,
-0x02,0x10,0x00,0x01,0x06,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x01,0x04,0x00,0x10,
-0x01,0x04,0x00,0x01,0x02,0x10,0x01,0x04,0x00,0x01,0x46,0x10,0x00,0x01,0x02,0x10,
-0x00,0x10,0x01,0x04,0x00,0x10,0x01,0x04,0x00,0x01,0x0e,0x10,0x10,0x00,0x10,0x10,
-0x00,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x00,0x01,0x02,0x10,0x00,0x01,0x0e,0x10,
-0x00,0x10,0x00,0x10,0x00,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x00,0x01,0x02,0x10,
-0x00,0x01,0x0e,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x01,0x04,0x00,0x10,0x01,0x04,
-0x00,0x01,0x0e,0x10,0x00,0x01,0x02,0x10,0x00,0x10,0x00,0x01,0x02,0x10,0x00,0x10,
-0x00,0x01,0xde,0x50,0x01,0x07,0x55,0x01,0x07,0xa5,0x01,0x07,0xaa,0x01,0x0f,0x0a,
-0x01,0x07,0x01,0x00
-};
-
-const unsigned char palette[16]={ 0x0f,0x21,0x10,0x30,0x0f,0x14,0x21,0x31,0x0f,0x29,0x16,0x26,0x0f,0x09,0x19,0x29 };	//palette data
-
-//#link "tileset1.c"
-
-// tile set, two planes for 4 colors
-extern unsigned char TILESET[8*256];
-
-
-void main(void)
-{
-	//rendering is disabled at the startup, and palette is all black
-	pal_bg(palette);//set background palette from an array
-
-	//copy tileset to RAM
-  	vram_adr(0x0);
-	vram_write((unsigned char*)TILESET, sizeof(TILESET));
-  
-	//unpack nametable into the VRAM
-	vram_adr(0x2000);
-	vram_unrle(test);
-
-  	//enable rendering
-	ppu_on_all();
-
-	while(1);//do nothing, infinite loop
-}
diff --git a/presets/nes/nesppu.asm b/presets/nes/nesppu.asm
index 20462c5d..4ca893d6 100644
--- a/presets/nes/nesppu.asm
+++ b/presets/nes/nesppu.asm
@@ -44,18 +44,21 @@ PrevRandom subroutine
 
 ;;;;; CONTROLLER READING
 
-ReadJoypad subroutine
+ReadJoypad0 subroutine
+	ldy #0
+ReadJoypadY
         lda #$01
-        sta JOYPAD1	; set strobe bit
-        tax		; X = 1
+        sta JOYPAD1,y	; set strobe bit
         lsr        	; now A is 0
-        sta JOYPAD1	; clear strobe bit
+        sta JOYPAD1,y	; clear strobe bit
+        ldx #8		; read 8 bits
 .loop:
-        lda JOYPAD1	; load controller state
+	pha		; save A (result)
+        lda JOYPAD1,y	; load controller state
         lsr        	; bit 0 -> carry
-        txa		; X -> A
-        rol		; carry -> bit 0 of result, bit 7 -> carry
-        tax		; A -> X
-        bcc .loop	; repeat until 1 shifted out
+        pla		; restore A (result)
+        rol		; carry -> bit 0 of result
+        dex		; X = X - 1
+        bne .loop	; repeat if X is 0
         rts		; controller bits returned in A
 
diff --git a/presets/nes/ppuhello.c b/presets/nes/ppuhello.c
new file mode 100644
index 00000000..eb42215f
--- /dev/null
+++ b/presets/nes/ppuhello.c
@@ -0,0 +1,48 @@
+
+#include <nes.h>
+
+const unsigned char TEXT[]="Hello PPU!!!!";
+
+const unsigned char PALETTE[]={0x1, 0x00, 0x10, 0x20}; // blue, gray, lt gray, white
+
+void main (void) {
+  unsigned char index; // used in 'for' loops
+
+  // if we've just powered on,
+  // wait for PPU to warm-up
+  waitvsync();
+  waitvsync();
+
+  // turn off screen
+  PPU.control = 0x0; // NMI off
+  PPU.mask = 0x0; // screen off
+
+  // load the palette
+  // set PPU address to 0x3f00
+  PPU.vram.address = 0x3f;
+  PPU.vram.address = 0x00;
+  for (index = 0; index < sizeof(PALETTE); index++) {
+    PPU.vram.data = PALETTE[index];
+  }
+
+  // load the text into VRAM
+  // set PPU address to 0x21c9
+  PPU.vram.address = 0x21;
+  PPU.vram.address = 0xc9;
+  for (index = 0; index < sizeof(TEXT); index++) {
+    PPU.vram.data = TEXT[index];
+  }
+
+  // reset the scroll position to 0
+  PPU.scroll = 0;
+  PPU.scroll = 0;
+  // reset the PPU address to 0x2000 (frame start)
+  PPU.vram.address = 0x20;
+  PPU.vram.address = 0x00;
+ 
+  // turn on the screen
+  PPU.mask = 0x1e;
+
+  // infinite loop
+  while (1);
+}
diff --git a/presets/nes/rletitle.c b/presets/nes/rletitle.c
new file mode 100644
index 00000000..e248f485
--- /dev/null
+++ b/presets/nes/rletitle.c
@@ -0,0 +1,49 @@
+
+// this example code unpacks a RLE'd nametable into the VRAM
+// you can create the source data using NES Screen Tool
+
+#include "neslib.h"
+
+extern const byte climbr_title_pal[16];
+extern const byte climbr_title_rle[];
+
+// link the pattern table into CHR ROM
+//#link "chr_generic.s"
+
+// link title screen palette and RLE nametable
+//#link "climbr_title.s"
+
+
+void fade_in() {
+  byte vb;
+  for (vb=0; vb<=4; vb++) {
+    // set virtual bright vaule
+    pal_bright(vb);
+    // wait for 4/60 sec
+    ppu_wait_frame();
+    ppu_wait_frame();
+    ppu_wait_frame();
+    ppu_wait_frame();
+  }
+}
+
+void show_title_screen(const byte* pal, const byte* rle) {
+  // disable rendering
+  ppu_off();
+  // set palette, virtual bright to 0 (total black)
+  pal_bg(pal);
+  pal_bright(0);
+  // unpack nametable into the VRAM
+  vram_adr(0x2000);
+  vram_unrle(rle);
+  // enable rendering
+  ppu_on_all();
+  // fade in from black
+  fade_in();
+}
+
+void main(void)
+{
+  show_title_screen(climbr_title_pal, climbr_title_rle);
+  while(1);//do nothing, infinite loop
+}
diff --git a/presets/nes/siegegame.c b/presets/nes/siegegame.c
index 6fd3e14a..41f05efd 100644
--- a/presets/nes/siegegame.c
+++ b/presets/nes/siegegame.c
@@ -26,14 +26,16 @@ byte getchar(byte x, byte y) {
   word addr = NTADR_A(x,y);
   byte rd;
   // wait for VBLANK to start
-  ppu_wait_nmi();
+  ppu_wait_frame();
+  // set vram address and read byte
   vram_adr(addr);
   vram_read(&rd, 1);
+  // scroll registers are corrupt
+  // fix by setting vram address
   vram_adr(0x0);
-  return rd + 0x20;
+  return rd;
 }
 
-
 void cputcxy(byte x, byte y, char ch) {
   putbytes(NTADR_A(x,y), &ch, 1);
 }
@@ -137,7 +139,7 @@ void move_player(Player* p) {
   cputcxy(p->x, p->y, p->tail_attr);
   p->x += DIR_X[p->dir];
   p->y += DIR_Y[p->dir];
-  if (getchar(p->x, p->y) != ' ')
+  if (getchar(p->x, p->y) != 0)
     p->collided = 1;
   draw_player(p);
 }
diff --git a/presets/nes/vrambuf.c b/presets/nes/vrambuf.c
index d76ed134..e486e76a 100644
--- a/presets/nes/vrambuf.c
+++ b/presets/nes/vrambuf.c
@@ -7,7 +7,7 @@ byte updptr = 0;
 
 // add EOF marker to buffer (but don't increment pointer)
 void cendbuf(void) {
-  updbuf[updptr] = NT_UPD_EOF;
+  VRAMBUF_SET(NT_UPD_EOF);
 }
 
 // clear vram buffer and place EOF marker
diff --git a/presets/nes/vrambuf.h b/presets/nes/vrambuf.h
index 38f2339b..c8ea28aa 100644
--- a/presets/nes/vrambuf.h
+++ b/presets/nes/vrambuf.h
@@ -8,7 +8,7 @@
 #define VBUFSIZE 128
 
 // update buffer starts at $100 (stack page)
-#define updbuf ((byte*)0x100)
+#define updbuf ((byte* const)0x100)
 
 // index to end of buffer
 extern byte updptr;
@@ -19,11 +19,15 @@ extern byte updptr;
   VRAMBUF_ADD(addr);\
   VRAMBUF_ADD(len);
 
-// macro to add a single byte to buffer
-#define VRAMBUF_ADD(b)\
+// macro to set a single byte in buffer
+#define VRAMBUF_SET(b)\
   __A__ = (b);\
   asm("ldy %v", updptr);\
-  asm("sta $100,y");\
+  asm("sta $100,y");
+
+// macro to set a single byte to buffer, then increment
+#define VRAMBUF_ADD(b)\
+  VRAMBUF_SET(b)\
   asm("inc %v", updptr);
 
 // add EOF marker to buffer (but don't increment pointer)
diff --git a/presets/nes/vrambuffer.c b/presets/nes/vrambuffer.c
index 71119c15..5396ffde 100644
--- a/presets/nes/vrambuffer.c
+++ b/presets/nes/vrambuffer.c
@@ -28,7 +28,7 @@ void scroll_demo() {
     // wait for next frame
     // and flush VRAM buffer
     cflushnow();
-    // set scroll register
+    // set scroll (shadow) registers
     scroll(x, y);
     // update y variable
     y += dy;
diff --git a/src/platform/nes.ts b/src/platform/nes.ts
index a8f16f37..2421f921 100644
--- a/src/platform/nes.ts
+++ b/src/platform/nes.ts
@@ -14,7 +14,7 @@ const JSNES_PRESETS = [
   {id:'ex2.asm', name:'Scrolling Demo (ASM)'},
   {id:'ex3.asm', name:'Sprite Demo (ASM)'},
   {id:'ex4.asm', name:'Controller Demo (ASM)'},
-  {id:'neslib1.c', name:'Text'},
+  {id:'hello.c', name:'Text'},
   {id:'scroll.c', name:'Scrolling'},
   {id:'vrambuffer.c', name:'VRAM Buffer'},
   {id:'sprites.c', name:'Sprites'},
@@ -22,9 +22,10 @@ const JSNES_PRESETS = [
   {id:'flicker.c', name:'Flickering Sprites'},
   {id:'metacursor.c', name:'Controllers'},
   {id:'metatrigger.c', name:'Trigger Mode + Vbright'},
-  {id:'neslib5.c', name:'RLE Unpack'},
+  {id:'rletitle.c', name:'Title Screen RLE'},
   {id:'statusbar.c', name:'Split Status Bar'},
   {id:'horizmask.c', name:'Offscreen Scrolling'},
+  {id:'attributes.c', name:'Attribute Table + Pixels'},
   {id:'music.c', name:'Music Player'},
   {id:'siegegame.c', name:'Siege Game'},
   {id:'shoot2.c', name:'Solarian Game'},
diff --git a/src/ui.ts b/src/ui.ts
index 1e2c4348..dc87f852 100644
--- a/src/ui.ts
+++ b/src/ui.ts
@@ -843,6 +843,7 @@ function resetAndDebug() {
 
 var lastBreakExpr = "c.PC == 0x6000";
 function _breakExpression() {
+  console.log(platform.saveState());
   var exprs = window.prompt("Enter break expression", lastBreakExpr);
   if (exprs) {
     var fn = new Function('c', 'return (' + exprs + ');').bind(platform);
diff --git a/tss b/tss
index 5b5ee67f..d630ddcb 160000
--- a/tss
+++ b/tss
@@ -1 +1 @@
-Subproject commit 5b5ee67fc06956bc7dce51726e98812d2d897eaa
+Subproject commit d630ddcb29d74a178cde043d74188fac35d6a21f