diff --git a/index.html b/index.html
index db5070ed..8ef7247e 100644
--- a/index.html
+++ b/index.html
@@ -283,6 +283,7 @@ canvas.pixelated {
 
 <script src="local/williams/defender.js"></script>
 <script src="local/williams/robotron.js"></script>
+<script src="local/atarivec/gravitar/gravitar.js"></script>
 
 <script src="FileSaver.js/FileSaver.min.js"></script>
 <script src="octokat.js/dist/octokat.js"></script>
diff --git a/src/disasm.js b/src/disasm.js
index 84755bdc..cfa7ebd2 100644
--- a/src/disasm.js
+++ b/src/disasm.js
@@ -2,7 +2,7 @@
 var OPS_6502 = [
   {mn:"BRK",am:"",nb:1,il:0,c1:7,c2:0}, // 00
   {mn:"ORA",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // 01
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 02
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 02
   {mn:"SLO",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // 03
   {mn:"NOP",am:"aa",nb:2,il:1,c1:3,c2:0}, // 04
   {mn:"ORA",am:"aa",nb:2,il:0,c1:3,c2:0}, // 05
@@ -18,7 +18,7 @@ var OPS_6502 = [
   {mn:"SLO",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // 0F
   {mn:"BPL",am:"branch",nb:2,il:0,c1:2,c2:2}, // 10
   {mn:"ORA",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // 11
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 12
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 12
   {mn:"SLO",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // 13
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // 14
   {mn:"ORA",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 15
@@ -26,7 +26,7 @@ var OPS_6502 = [
   {mn:"SLO",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // 17
   {mn:"CLC",am:"",nb:1,il:0,c1:2,c2:0}, // 18
   {mn:"ORA",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // 19
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // 1A
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // 1A
   {mn:"SLO",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // 1B
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // 1C
   {mn:"ORA",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // 1D
@@ -34,7 +34,7 @@ var OPS_6502 = [
   {mn:"SLO",am:"AAAA,x",nb:3,il:1,c1:7,c2:1}, // 1F
   {mn:"JSR",am:"AAAA",nb:3,il:0,c1:6,c2:0}, // 20
   {mn:"AND",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // 21
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 22
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 22
   {mn:"RLA",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // 23
   {mn:"BIT",am:"aa",nb:2,il:0,c1:3,c2:0}, // 24
   {mn:"AND",am:"aa",nb:2,il:0,c1:3,c2:0}, // 25
@@ -50,7 +50,7 @@ var OPS_6502 = [
   {mn:"RLA",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // 2F
   {mn:"BMI",am:"branch",nb:2,il:0,c1:2,c2:2}, // 30
   {mn:"AND",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // 31
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 32
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 32
   {mn:"RLA",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // 33
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // 34
   {mn:"AND",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 35
@@ -58,7 +58,7 @@ var OPS_6502 = [
   {mn:"RLA",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // 37
   {mn:"SEC",am:"",nb:1,il:0,c1:2,c2:0}, // 38
   {mn:"AND",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // 39
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // 3A
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // 3A
   {mn:"RLA",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // 3B
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // 3C
   {mn:"AND",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // 3D
@@ -66,7 +66,7 @@ var OPS_6502 = [
   {mn:"RLA",am:"AAAA,x",nb:3,il:1,c1:7,c2:1}, // 3F
   {mn:"RTI",am:"",nb:1,il:0,c1:6,c2:0}, // 40
   {mn:"EOR",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // 41
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 42
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 42
   {mn:"SRE",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // 43
   {mn:"NOP",am:"aa",nb:2,il:1,c1:3,c2:0}, // 44
   {mn:"EOR",am:"aa",nb:2,il:0,c1:3,c2:0}, // 45
@@ -82,7 +82,7 @@ var OPS_6502 = [
   {mn:"SRE",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // 4F
   {mn:"BVC",am:"branch",nb:2,il:0,c1:2,c2:2}, // 50
   {mn:"EOR",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // 51
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 52
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 52
   {mn:"SRE",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // 53
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // 54
   {mn:"EOR",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 55
@@ -90,7 +90,7 @@ var OPS_6502 = [
   {mn:"SRE",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // 57
   {mn:"CLI",am:"",nb:1,il:0,c1:2,c2:0}, // 58
   {mn:"EOR",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // 59
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // 5A
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // 5A
   {mn:"SRE",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // 5B
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // 5C
   {mn:"EOR",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // 5D
@@ -98,7 +98,7 @@ var OPS_6502 = [
   {mn:"SRE",am:"AAAA,x",nb:3,il:1,c1:7,c2:1}, // 5F
   {mn:"RTS",am:"",nb:1,il:0,c1:6,c2:0}, // 60
   {mn:"ADC",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // 61
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 62
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 62
   {mn:"RRA",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // 63
   {mn:"NOP",am:"aa",nb:2,il:1,c1:3,c2:0}, // 64
   {mn:"ADC",am:"aa",nb:2,il:0,c1:3,c2:0}, // 65
@@ -114,7 +114,7 @@ var OPS_6502 = [
   {mn:"RRA",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // 6F
   {mn:"BVS",am:"branch",nb:2,il:0,c1:2,c2:2}, // 70
   {mn:"ADC",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // 71
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 72
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 72
   {mn:"RRA",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // 73
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // 74
   {mn:"ADC",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 75
@@ -122,32 +122,32 @@ var OPS_6502 = [
   {mn:"RRA",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // 77
   {mn:"SEI",am:"",nb:1,il:0,c1:2,c2:0}, // 78
   {mn:"ADC",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // 79
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // 7A
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // 7A
   {mn:"RRA",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // 7B
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // 7C
   {mn:"ADC",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // 7D
   {mn:"ROR",am:"AAAA,x",nb:3,il:0,c1:7,c2:0}, // 7E
   {mn:"RRA",am:"AAAA,x",nb:3,il:1,c1:7,c2:1}, // 7F
-  {mn:"NOP",am:"#aa",nb:0,il:1,c1:0,c2:0}, // 80
+  {mn:"NOP",am:"#aa",nb:2,il:1,c1:0,c2:0}, // 80
   {mn:"STA",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // 81
-  {mn:"NOP",am:"#aa",nb:0,il:1,c1:0,c2:0}, // 82
+  {mn:"NOP",am:"#aa",nb:2,il:1,c1:0,c2:0}, // 82
   {mn:"SAX",am:"(aa,x)",nb:2,il:1,c1:6,c2:1}, // 83
   {mn:"STY",am:"aa",nb:2,il:0,c1:3,c2:0}, // 84
   {mn:"STA",am:"aa",nb:2,il:0,c1:3,c2:0}, // 85
   {mn:"STX",am:"aa",nb:2,il:0,c1:3,c2:0}, // 86
   {mn:"SAX",am:"aa",nb:2,il:1,c1:3,c2:0}, // 87
   {mn:"DEY",am:"",nb:1,il:0,c1:2,c2:0}, // 88
-  {mn:"NOP",am:"#aa",nb:0,il:1,c1:0,c2:0}, // 89
+  {mn:"NOP",am:"#aa",nb:2,il:1,c1:0,c2:0}, // 89
   {mn:"TXA",am:"",nb:1,il:0,c1:2,c2:0}, // 8A
-  {mn:"ANE",am:"#aa",nb:0,il:1,c1:0,c2:0}, // 8B
+  {mn:"ANE",am:"#aa",nb:2,il:1,c1:0,c2:0}, // 8B
   {mn:"STY",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // 8C
   {mn:"STA",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // 8D
   {mn:"STX",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // 8E
   {mn:"SAX",am:"AAAA",nb:3,il:1,c1:4,c2:0}, // 8F
   {mn:"BCC",am:"branch",nb:2,il:0,c1:2,c2:2}, // 90
   {mn:"STA",am:"(aa),y",nb:2,il:0,c1:6,c2:0}, // 91
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // 92
-  {mn:"SHA",am:"(aa),y",nb:0,il:1,c1:0,c2:0}, // 93
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // 92
+  {mn:"SHA",am:"(aa),y",nb:2,il:1,c1:0,c2:0}, // 93
   {mn:"STY",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 94
   {mn:"STA",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // 95
   {mn:"STX",am:"aa,y",nb:2,il:0,c1:4,c2:0}, // 96
@@ -155,11 +155,11 @@ var OPS_6502 = [
   {mn:"TYA",am:"",nb:1,il:0,c1:2,c2:0}, // 98
   {mn:"STA",am:"AAAA,y",nb:3,il:0,c1:5,c2:0}, // 99
   {mn:"TXS",am:"",nb:1,il:0,c1:2,c2:0}, // 9A
-  {mn:"SHS",am:"AAAA,y",nb:0,il:1,c1:0,c2:0}, // 9B
-  {mn:"SHY",am:"AAAA,x",nb:0,il:1,c1:0,c2:0}, // 9C
+  {mn:"SHS",am:"AAAA,y",nb:3,il:1,c1:0,c2:0}, // 9B
+  {mn:"SHY",am:"AAAA,x",nb:3,il:1,c1:0,c2:0}, // 9C
   {mn:"STA",am:"AAAA,x",nb:3,il:0,c1:5,c2:0}, // 9D
-  {mn:"SHX",am:"AAAA,y",nb:0,il:1,c1:0,c2:0}, // 9E
-  {mn:"SHA",am:"AAAA,y",nb:0,il:1,c1:0,c2:0}, // 9F
+  {mn:"SHX",am:"AAAA,y",nb:3,il:1,c1:0,c2:0}, // 9E
+  {mn:"SHA",am:"AAAA,y",nb:3,il:1,c1:0,c2:0}, // 9F
   {mn:"LDY",am:"#aa",nb:2,il:0,c1:2,c2:0}, // A0
   {mn:"LDA",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // A1
   {mn:"LDX",am:"#aa",nb:2,il:0,c1:2,c2:0}, // A2
@@ -171,14 +171,14 @@ var OPS_6502 = [
   {mn:"TAY",am:"",nb:1,il:0,c1:2,c2:0}, // A8
   {mn:"LDA",am:"#aa",nb:2,il:0,c1:2,c2:0}, // A9
   {mn:"TAX",am:"",nb:1,il:0,c1:2,c2:0}, // AA
-  {mn:"LXA",am:"#aa",nb:0,il:1,c1:0,c2:0}, // AB
+  {mn:"LXA",am:"#aa",nb:2,il:1,c1:0,c2:0}, // AB
   {mn:"LDY",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // AC
   {mn:"LDA",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // AD
   {mn:"LDX",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // AE
   {mn:"LAX",am:"AAAA",nb:3,il:1,c1:4,c2:0}, // AF
   {mn:"BCS",am:"branch",nb:2,il:0,c1:2,c2:2}, // B0
   {mn:"LDA",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // B1
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // B2
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // B2
   {mn:"LAX",am:"(aa),y",nb:2,il:1,c1:5,c2:1}, // B3
   {mn:"LDY",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // B4
   {mn:"LDA",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // B5
@@ -187,14 +187,14 @@ var OPS_6502 = [
   {mn:"CLV",am:"",nb:1,il:0,c1:2,c2:0}, // B8
   {mn:"LDA",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // B9
   {mn:"TSX",am:"",nb:1,il:0,c1:2,c2:0}, // BA
-  {mn:"LAS",am:"AAAA,y",nb:0,il:1,c1:0,c2:0}, // BB
+  {mn:"LAS",am:"AAAA,y",nb:3,il:1,c1:0,c2:0}, // BB
   {mn:"LDY",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // BC
   {mn:"LDA",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // BD
   {mn:"LDX",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // BE
   {mn:"LAX",am:"AAAA,y",nb:3,il:1,c1:4,c2:1}, // BF
   {mn:"CPY",am:"#aa",nb:2,il:0,c1:2,c2:0}, // C0
   {mn:"CMP",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // C1
-  {mn:"NOP",am:"#aa",nb:0,il:1,c1:0,c2:0}, // C2
+  {mn:"NOP",am:"#aa",nb:2,il:1,c1:0,c2:0}, // C2
   {mn:"DCP",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // C3
   {mn:"CPY",am:"aa",nb:2,il:0,c1:3,c2:0}, // C4
   {mn:"CMP",am:"aa",nb:2,il:0,c1:3,c2:0}, // C5
@@ -210,7 +210,7 @@ var OPS_6502 = [
   {mn:"DCP",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // CF
   {mn:"BNE",am:"branch",nb:2,il:0,c1:2,c2:2}, // D0
   {mn:"CMP",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // D1
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // D2
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // D2
   {mn:"DCP",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // D3
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // D4
   {mn:"CMP",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // D5
@@ -218,7 +218,7 @@ var OPS_6502 = [
   {mn:"DCP",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // D7
   {mn:"CLD",am:"",nb:1,il:0,c1:2,c2:0}, // D8
   {mn:"CMP",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // D9
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // DA
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // DA
   {mn:"DCP",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // DB
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // DC
   {mn:"CMP",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // DD
@@ -226,7 +226,7 @@ var OPS_6502 = [
   {mn:"DCP",am:"AAAA,x",nb:3,il:1,c1:7,c2:1}, // DF
   {mn:"CPX",am:"#aa",nb:2,il:0,c1:2,c2:0}, // E0
   {mn:"SBC",am:"(aa,x)",nb:2,il:0,c1:6,c2:0}, // E1
-  {mn:"NOP",am:"#aa",nb:0,il:1,c1:0,c2:0}, // E2
+  {mn:"NOP",am:"#aa",nb:2,il:1,c1:0,c2:0}, // E2
   {mn:"ISB",am:"(aa,x)",nb:2,il:1,c1:8,c2:1}, // E3
   {mn:"CPX",am:"aa",nb:2,il:0,c1:3,c2:0}, // E4
   {mn:"SBC",am:"aa",nb:2,il:0,c1:3,c2:0}, // E5
@@ -235,14 +235,14 @@ var OPS_6502 = [
   {mn:"INX",am:"",nb:1,il:0,c1:2,c2:0}, // E8
   {mn:"SBC",am:"#aa",nb:2,il:0,c1:2,c2:0}, // E9
   {mn:"NOP",am:"",nb:1,il:0,c1:2,c2:0}, // EA
-  {mn:"SBC",am:"#aa",nb:0,il:1,c1:0,c2:0}, // EB
+  {mn:"SBC",am:"#aa",nb:2,il:1,c1:0,c2:0}, // EB
   {mn:"CPX",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // EC
   {mn:"SBC",am:"AAAA",nb:3,il:0,c1:4,c2:0}, // ED
   {mn:"INC",am:"AAAA",nb:3,il:0,c1:6,c2:0}, // EE
   {mn:"ISB",am:"AAAA",nb:3,il:1,c1:6,c2:0}, // EF
   {mn:"BEQ",am:"branch",nb:2,il:0,c1:2,c2:2}, // F0
   {mn:"SBC",am:"(aa),y",nb:2,il:0,c1:5,c2:1}, // F1
-  {mn:"KIL",am:"",nb:0,il:1,c1:0,c2:0}, // F2
+  {mn:"KIL",am:"",nb:1,il:1,c1:0,c2:0}, // F2
   {mn:"ISB",am:"(aa),y",nb:2,il:1,c1:8,c2:1}, // F3
   {mn:"NOP",am:"aa,x",nb:2,il:1,c1:4,c2:0}, // F4
   {mn:"SBC",am:"aa,x",nb:2,il:0,c1:4,c2:0}, // F5
@@ -250,7 +250,7 @@ var OPS_6502 = [
   {mn:"ISB",am:"aa,x",nb:2,il:1,c1:6,c2:1}, // F7
   {mn:"SED",am:"",nb:1,il:0,c1:2,c2:0}, // F8
   {mn:"SBC",am:"AAAA,y",nb:3,il:0,c1:4,c2:1}, // F9
-  {mn:"NOP",am:"",nb:0,il:1,c1:0,c2:0}, // FA
+  {mn:"NOP",am:"",nb:1,il:1,c1:0,c2:0}, // FA
   {mn:"ISB",am:"AAAA,y",nb:3,il:1,c1:7,c2:1}, // FB
   {mn:"NOP",am:"AAAA,x",nb:3,il:1,c1:4,c2:1}, // FC
   {mn:"SBC",am:"AAAA,x",nb:3,il:0,c1:4,c2:1}, // FD
@@ -281,7 +281,7 @@ function disassemble6502(pc, b0, b1, b2) {
   var s = op.mn;
   var am = op.am;
   if (am == 'branch') {
-    var offset = (b1 < 0x80) ? (pc+b1) : (pc-(256-b1));
+    var offset = (b1 < 0x80) ? (pc+2+b1) : (pc+2-(256-b1));
     offset &= 0xffff;
     am = '$'+formatHex(offset, 4);
   } else {
diff --git a/src/emu.js b/src/emu.js
index a40e33ed..4f637735 100644
--- a/src/emu.js
+++ b/src/emu.js
@@ -154,12 +154,24 @@ var VectorVideo = function(mainElement, width, height) {
     ctx.globalCompositeOperation = 'lighter';
   }
 
-  this.drawLine = function(x1, y1, x2, y2, intensity) {
+  var COLORS = [
+    '#000000',
+    '#0000ff',
+    '#00ff00',
+    '#00ffff',
+    '#ff0000',
+    '#ff00ff',
+    '#ffff00',
+    '#ffffff'
+  ];
+
+  this.drawLine = function(x1, y1, x2, y2, intensity, color) {
     //console.log(x1, y1, x2, y2, intensity);
     if (intensity > 0) {
       // TODO: landscape vs portrait
+      ctx.globalAlpha = intensity / 255.0;
       ctx.beginPath();
-      // TODO: dots
+      // TODO: bright dots
       var jx = jitter * (Math.random() - 0.5);
       var jy = jitter * (Math.random() - 0.5);
       x1 += jx;
@@ -168,8 +180,7 @@ var VectorVideo = function(mainElement, width, height) {
       y2 += jy;
       ctx.moveTo(x1, height-y1);
       ctx.lineTo(x2+1, height-y2);
-      ctx.strokeStyle = '#ffffff';
-      ctx.lineWidth = intensity*0.1;
+      ctx.strokeStyle = COLORS[color & 7];
       ctx.stroke();
     }
   }
@@ -492,7 +503,7 @@ var Base6502Platform = function() {
   }
   this.runUntilReturn = function() {
     var depth = 1;
-    self.runEval(function(c) {
+    this.runEval(function(c) {
       if (depth <= 0 && c.T == 0)
         return true;
       if (c.o == 0x20)
@@ -678,7 +689,7 @@ var BaseZ80Platform = function() {
 	this.runUntilReturn = function() {
     var self = this;
     var depth = 1;
-    self.runEval(function(c) {
+    this.runEval(function(c) {
       if (depth <= 0)
         return true;
 			var op = self.readAddress(c.PC);
diff --git a/src/platform/vector.js b/src/platform/vector.js
index 946ab31a..a0ae2a81 100644
--- a/src/platform/vector.js
+++ b/src/platform/vector.js
@@ -1,5 +1,8 @@
 "use strict";
 
+// http://www.computerarcheology.com/Arcade/Asteroids/DVG.html
+// http://arcarc.xmission.com/Tech/neilw_xy.txt
+
 var VECTOR_PRESETS = [
 ]
 
@@ -16,6 +19,17 @@ var ASTEROIDS_KEYCODE_MAP = makeKeycodeMap([
   [Keys.VK_LEFT, 15, 0xff],
 ]);
 
+var GRAVITAR_KEYCODE_MAP = makeKeycodeMap([
+  [Keys.VK_SHIFT, 1, -0x1],
+  [Keys.VK_SPACE, 1, -0x2],
+  [Keys.VK_5, 0, 0x2],
+  [Keys.VK_6, 0, 0x1],
+  [Keys.VK_1, 2, 0x20],
+  [Keys.VK_2, 2, 0x40],
+  [Keys.VK_UP, 1, -0x10],
+  [Keys.VK_RIGHT, 1, -0x4],
+  [Keys.VK_LEFT, 1, -0x8],
+]);
 
 var AtariVectorPlatform = function(mainElement) {
   var self = this;
@@ -54,7 +68,7 @@ var AtariVectorPlatform = function(mainElement) {
 
       write: new AddressDecoder([
         [0x0,    0x3ff,  0x3ff,  function(a,v) { cpuram.mem[a] = v; }],
-        [0x3000, 0x3000, 0,      function(a,v) { dvg.runUntilHalt(); }],
+        [0x3000, 0x3000, 0,      function(a,v) { dvg.runUntilHalt(0); }],
         // TODO: draw asynchronous or allow poll of HALT ($2002)
         [0x4000, 0x5fff, 0x1fff, function(a,v) { dvgram.mem[a] = v; }],
       ], {gmask:0x7fff})
@@ -63,7 +77,7 @@ var AtariVectorPlatform = function(mainElement) {
     cpu = self.newCPU(bus);
     // create video/audio
     video = new VectorVideo(mainElement,1024,1024);
-    dvg = new DVGStateMachine(bus, video);
+    dvg = new DVGBWStateMachine(bus, video, 0x4000);
     audio = new SampleAudio(cpuFrequency);
     video.create();
     timer = new AnimationTimer(60, function() {
@@ -137,9 +151,149 @@ var AtariVectorPlatform = function(mainElement) {
   }
 }
 
+var AtariColorVectorPlatform = function(mainElement) {
+  var self = this;
+  var masterFrequency = 12096000.0;
+  var cpuFrequency = masterFrequency / 8;
+  var nmiFrequency = masterFrequency / 4096 / 12;
+  var cpuCyclesPerNMI = Math.round(cpuFrequency / nmiFrequency);
+  var cpuCyclesPerFrame = Math.round(cpuFrequency / 60);
+  var cpu, cpuram, dvgram, rom, vecrom, bus, dvg, earom;
+  var video, audio, timer;
+  var clock;
+  var switches = new RAM(16).mem;
+  var nmicount = cpuCyclesPerNMI;
+  var earom_offset, earom_data;
+
+  this.__proto__ = new Base6502Platform();
+
+  this.getPresets = function() {
+    return VECTOR_PRESETS;
+  }
+
+  this.start = function() {
+    cpuram = new RAM(0x800);
+    dvgram = new RAM(0x2000);
+    earom = new RAM(0x40);
+    rom = padBytes(new lzgmini().decode(GRAVITAR_ROM).slice(0), 0x7000+1);
+    vecrom = padBytes(new lzgmini().decode(GRAVITAR_VECROM).slice(0), 0x6000-0x2800+1);
+    switches[0] = 0xff;
+    switches[1] = 0xff;
+    switches[2] = 0xff;
+    // bus
+    bus = {
+
+      read: new AddressDecoder([
+        [0x0,    0x7ff,  0x7ff,  function(a) { return cpuram.mem[a]; }],
+        [0x2000, 0x27ff, 0x7ff,  function(a) { return dvgram.mem[a]; }],
+        [0x2800, 0x5fff, 0x7fff, function(a) { return vecrom[a - 0x2800]; }],
+        //[0x2001, 0x2001, 0,      function(a) { return ((clock/500) & 1) ? 0xff : 0x00; }],
+        //[0x6000, 0x67ff, 0x7ff,  function(a) { /* pokey1 */ return 0; }],
+        //[0x6800, 0x6fff, 0x7ff,  function(a) { /* pokey2 */ return 0; }],
+        [0x7800, 0x7800, 0,      function(a) { return switches[0]; }],
+        [0x8000, 0x8000, 0,      function(a) { return switches[1]; }],
+        [0x8800, 0x8800, 0,      function(a) { return switches[2]; }],
+        //[0x7000, 0x7000, 0,      function(a) { /* EAROM read */ return 0; }],
+        //[0x8940, 0x897f, 0x3f,   function(a) { /* EAROM data */ return 0; }],
+        [0x8900, 0x8900, 0,      function(a) { /* EAROM read */ return earom_data; }],
+        [0x9000, 0xffff, 0xffff, function(a) { return rom[a - 0x9000]; }],
+      ]),
+
+      write: new AddressDecoder([
+        [0x0,    0x7ff,  0x7ff,  function(a,v) { cpuram.mem[a] = v; }],
+        [0x2000, 0x27ff, 0x7ff,  function(a,v) { dvgram.mem[a] = v; }],
+        [0x6000, 0x67ff, 0x7ff,  function(a,v) { /* pokey1 */ }],
+        [0x6800, 0x6fff, 0x7ff,  function(a,v) { /* pokey2 */ }],
+        [0x8800, 0x8800, 0,      function(a,v) { /* LEDs, etc */ }],
+        [0x8840, 0x8840, 0,      function(a,v) { dvg.runUntilHalt(0); }],
+        [0x8880, 0x8880, 0,      function(a,v) { dvg.reset(); }],
+        [0x88c0, 0x88c0, 0,      function(a,v) { /* IRQ ACK */ }],
+        [0x8900, 0x8900, 0,      function(a,v) { /* EAROM ctrl */
+          if (v == 9) earom_data=earom.mem[earom_offset];
+          if (v == 12) earom.mem[earom_offset]=earom_data;
+        }],
+        [0x8940, 0x897f, 0x3f,   function(a,v) { /* EAROM data */ earom_offset = a; earom_data = v; }],
+        [0x8980, 0x8980, 0,      function(a,v) { /* TODO: watchdog */ }],
+        // TODO: draw asynchronous or allow poll of HALT ($2002)
+        //[0, 0xffff, 0,    function(a,v) { console.log(hex(a,4),hex(v,2)); }],
+      ])
+
+    };
+    cpu = self.newCPU(bus);
+    // create video/audio
+    video = new VectorVideo(mainElement,1024,1024);
+    dvg = new DVGColorStateMachine(bus, video, 0x2000);
+    audio = new SampleAudio(cpuFrequency);
+    video.create();
+    timer = new AnimationTimer(60, function() {
+      video.clear();
+      var debugCond = self.getDebugCallback();
+      clock = 0;
+      for (var i=0; i<cpuCyclesPerFrame; i++) {
+        if (debugCond && debugCond()) { debugCond = null; }
+        clock++;
+        if (--nmicount == 0) {
+          //console.log("NMI", cpu.saveState());
+          var n = cpu.setIRQAndWait(); // TODO: only if I flag set
+          clock += n;
+          nmicount = cpuCyclesPerNMI - n;
+          //console.log(n, clock, nmicount);
+        }
+        cpu.clockPulse();
+        //cpu.executeInstruction();
+      }
+      self.restartDebugState();
+    });
+    setKeyboardFromMap(video, switches, GRAVITAR_KEYCODE_MAP);
+  }
+
+  this.loadROM = function(title, data) {
+    this.reset();
+  }
+
+  this.getRasterPosition = function() {
+    return {x:0, y:0}; // TODO
+  }
+
+  this.isRunning = function() {
+    return timer.isRunning();
+  }
+  this.pause = function() {
+    timer.stop();
+  }
+  this.resume = function() {
+    timer.start();
+  }
+  this.reset = function() {
+    this.clearDebug();
+    cpu.reset();
+  }
+  this.readAddress = function(addr) {
+    return bus.read(addr);
+  }
+
+  this.loadState = function(state) {
+    cpu.loadState(state.c);
+    cpuram.mem.set(state.cb);
+    dvgram.mem.set(state.db);
+    nmicount = state.nmic;
+  }
+  this.saveState = function() {
+    return {
+      c:cpu.saveState(),
+      cb:cpuram.mem.slice(0),
+      db:dvgram.mem.slice(0),
+      nmic:nmicount
+    }
+  }
+  this.getCPUState = function() {
+    return cpu.saveState();
+  }
+}
+
 //
 
-var VectorZ80Platform = function(mainElement, proto) {
+var Z80ColorVectorPlatform = function(mainElement, proto) {
   var self = this;
   var cpuFrequency = 3000000.0;
   var cpuCyclesPerFrame = Math.round(cpuFrequency/60);
@@ -155,34 +309,30 @@ var VectorZ80Platform = function(mainElement, proto) {
   }
 
   this.start = function() {
-    cpuram = new RAM(0x1000);
-    dvgram = new RAM(0x2000);
-    //switches[5] = 0xff;
-    //switches[7] = 0xff;
+    cpuram = new RAM(0x2000);
+    dvgram = new RAM(0x4000);
     // bus
     bus = {
 
       read: new AddressDecoder([
-        [0x0,    0x3fff, 0,      function(a) { return rom[a]; }],
-        [0x4000, 0x5fff, 0x1fff, function(a) { return dvgram.mem[a]; }],
-        [0x6000, 0x6fff, 0xfff,  function(a) { return cpuram.mem[a]; }],
-        [0x7001, 0x7001, 0,      function(a) { return ((clock/1000) & 1) ? 0xff : 0x00; }],
-        [0x7000, 0x7007, 0x7,    function(a) { return switches[a]; }],
-        [0x7400, 0x7407, 0x7,    function(a) { return switches[a+8]; }],
+        [0x0,    0x7fff, 0,      function(a) { return rom[a]; }],
+        [0x8000, 0x800f, 0xf,    function(a) { return switches[a]; }],
+        [0xa000, 0xdfff, 0x3fff, function(a) { return dvgram.mem[a]; }],
+        [0xe000, 0xffff, 0x1fff, function(a) { return cpuram.mem[a]; }],
       ]),
 
       write: new AddressDecoder([
-        [0x7000, 0x7000, 0,      function(a,v) { dvg.runUntilHalt(); }],
-        // TODO: draw asynchronous or allow poll of HALT ($2002)
-        [0x4000, 0x5fff, 0x1fff, function(a,v) { dvgram.mem[a] = v; }],
-        [0x6000, 0x6fff, 0xfff,  function(a,v) { cpuram.mem[a] = v; }],
+        [0x8840, 0x8840, 0,      function(a,v) { dvg.runUntilHalt(0); }],
+        [0x8880, 0x8880, 0,      function(a,v) { dvg.reset(); }],
+        [0xa000, 0xdfff, 0x3fff, function(a,v) { dvgram.mem[a] = v; }],
+        [0xe000, 0xffff, 0x1fff, function(a,v) { cpuram.mem[a] = v; }],
       ])
 
     };
     cpu = self.newCPU(bus);
     // create video/audio
     video = new VectorVideo(mainElement,1024,1024);
-    dvg = new DVGStateMachine(bus, video);
+    dvg = new DVGColorStateMachine(bus, video, 0xa000);
     audio = new SampleAudio(cpuFrequency);
     video.create();
     timer = new AnimationTimer(60, function() {
@@ -195,7 +345,7 @@ var VectorZ80Platform = function(mainElement, proto) {
   }
 
   this.loadROM = function(title, data) {
-    rom = padBytes(data, 0x4000);
+    rom = padBytes(data, 0x8000);
     this.reset();
   }
 
@@ -238,15 +388,15 @@ var VectorZ80Platform = function(mainElement, proto) {
 
 // DIGITAL VIDEO GENERATOR
 
-var DVGStateMachine = function(bus, video) {
+var DVGBWStateMachine = function(bus, video, bofs) {
   var self = this;
   var pc = 0;
   var x = 0;
   var y = 0;
   var gsc = 0;
-  var bofs = 0x4000;
   var pcstack = [];
   var running = false;
+  bofs &= 0xffff;
 
   function readWord(a) {
     a &= 0xfff;
@@ -262,14 +412,20 @@ var DVGStateMachine = function(bus, video) {
       return w;
   }
 
-  this.go = function() {
+  this.reset = function() {
     pc = 0;
     gsc = 7;
+    running = false;
+  }
+
+  this.go = function() {
+    this.reset();
     running = true;
   }
 
-  this.runUntilHalt = function() {
+  this.runUntilHalt = function(startpc) {
     this.go();
+    pc = startpc;
     for (var i=0; i<10000; i++) { // TODO: limit execution
       if (!running) break;
       this.nextInstruction();
@@ -302,7 +458,7 @@ var DVGStateMachine = function(bus, video) {
         var z = w2 >> 12;
         var x2 = x + ((decodeSigned(w2, 10) << 7) >> sc);
         var y2 = y + ((decodeSigned(w, 10) << 7) >> sc);
-        video.drawLine(x, y, x2, y2, z);
+        video.drawLine(x, y, x2, y2, z, 255);
         //console.log(pc.toString(16), w.toString(16), w2.toString(16), gsc, sc, x, y, x2, y2);
         x = x2;
         y = y2;
@@ -332,7 +488,7 @@ var DVGStateMachine = function(bus, video) {
         var x2 = x + ((decodeSigned(w, 2) << 7) >> sc);
         var y2 = y + ((decodeSigned(w>>8, 2) << 7) >> sc);
         var z = (w >> 4) & 0xf;
-        video.drawLine(x, y, x2, y2, z);
+        video.drawLine(x, y, x2, y2, z, 255);
         x = x2;
         y = y2;
         break;
@@ -341,7 +497,126 @@ var DVGStateMachine = function(bus, video) {
   }
 }
 
+var DVGColorStateMachine = function(bus, video, bofs) {
+  var self = this;
+  var pc = 0;
+  var x = 0;
+  var y = 0;
+  var scale = 1.0;
+  var color;
+  var statz;
+  var pcstack = [];
+  var running = false;
+  bofs &= 0xffff;
+
+  function readWord(a) {
+    a &= 0x1fff;
+    return bus.read(a*2+bofs) + (bus.read(a*2+bofs+1) << 8);
+  }
+
+  // twos complement
+  function decodeSigned(w, o2) {
+    var s = w & (1<<o2);
+    w = w & ((1<<o2)-1);
+    if (s)
+      return w-(1<<o2);
+    else
+      return w;
+  }
+
+  this.reset = function() {
+    pc = 0;
+    scale = 1.0;
+    color = 7;
+    statz = 15;
+    x = 512;
+    y = 512;
+    running = false;
+  }
+
+  this.go = function() {
+    this.reset();
+    running = true;
+  }
+
+  this.runUntilHalt = function(startpc) {
+    this.go();
+    pc = startpc;
+    for (var i=0; i<10000; i++) { // TODO: limit execution
+      if (!running) break;
+      this.nextInstruction();
+    }
+    //console.log('DVG',i);
+  }
+
+  this.nextInstruction = function() {
+    if (!running) return;
+    var w = readWord(pc);
+    var op = w >> 13;
+    //video.drawLine(pc, 1023, pc+1, 1023-op, 7);
+    //console.log(hex(pc), hex(w), op);
+    pc++;
+    switch (op) {
+      case 0: { // VCTR
+        var w2 = readWord(pc++);
+        var z = w2 >> 13;
+        if (z == 2) z = statz;
+        var x2 = x + Math.round(decodeSigned(w2, 12) * scale);
+        var y2 = y + Math.round(decodeSigned(w, 12) * scale);
+        video.drawLine(x, y, x2, y2, z<<4, color);
+        x = x2;
+        y = y2;
+        break;
+      }
+      case 1: // HALT
+        running = false;
+        break;
+      case 2: { // SVEC
+        var x2 = x + Math.round(decodeSigned(w, 4) * scale * 2);
+        var y2 = y + Math.round(decodeSigned(w>>8, 4) * scale * 2);
+        var z = (w >> 5) & 0x7;
+        if (z == 2) z = statz;
+        video.drawLine(x, y, x2, y2, z<<4, color);
+        x = x2;
+        y = y2;
+        break;
+      }
+      case 3: { // STAT/SCAL
+        if (w & 0x1000) {
+          var b = ((w >> 8) & 0x07)+8;
+          var l = (~w) & 0xff;
+          scale = ((l << 16) >> b) / 32768.0;
+        } else {
+          color = w & 7;
+          statz = (w >> 4) & 0xf;
+        }
+        break;
+      }
+      case 4: // CNTR
+        x = 512;
+        y = 512;
+        break;
+      case 6: // RTSL
+        if (pcstack.length == 0) {
+          //console.log("stack underflow"); // TODO: error?
+        } else {
+          pc = pcstack.pop();
+        }
+        break;
+      case 5: // JSRL
+        pcstack.push(pc);
+      case 7: // JMPL
+        if (pc == 0)
+          running = false;
+        else
+          pc = w & 0x1fff;
+        break;
+    }
+  }
+}
+
 //
 
 PLATFORMS['vector-ataribw'] = AtariVectorPlatform;
-PLATFORMS['vector-z80'] = VectorZ80Platform;
+PLATFORMS['vector-ataricolor'] = AtariColorVectorPlatform;
+PLATFORMS['vector-z80color'] = Z80ColorVectorPlatform;
diff --git a/src/ui.js b/src/ui.js
index 6d4551ac..2ea9e04e 100644
--- a/src/ui.js
+++ b/src/ui.js
@@ -530,12 +530,26 @@ function getCurrentLine() {
   return editor.getCursor().line+1;
 }
 
-function runToCursor() {
-  setupBreakpoint();
+function getCurrentPC() {
   var line = getCurrentLine();
   var pc = sourcefile.line2offset[line];
+  if (!(pc >= 0)) {
+    line = disasmview.getCursor().line;
+    if (line) {
+      var toks = disasmview.getLine(line).split(/\s+/);
+      if (toks) {
+        pc = parseInt(toks[0], 16);
+      }
+    }
+  }
+  return pc;
+}
+
+function runToCursor() {
+  setupBreakpoint();
+  var pc = getCurrentPC();
   if (pc >= 0) {
-    console.log("Run to", line, pc.toString(16));
+    console.log("Run to", pc.toString(16));
     platform.runEval(function(c) {
       return c.PC == pc;
     });
@@ -795,7 +809,7 @@ function updateDisassembly() {
         s += dline;
         if (a == pc) selline = curline;
         curline++;
-        a += disasm.nbytes;
+        a += disasm.nbytes || 1;
       }
       return s;
     }
diff --git a/src/worker/workermain.js b/src/worker/workermain.js
index 0f3c09af..a4c3dc6e 100644
--- a/src/worker/workermain.js
+++ b/src/worker/workermain.js
@@ -25,11 +25,11 @@ var PLATFORM_PARAMS = {
     data_start: 0x9000,
     data_size: 0x3000,
   },
-  'vector-z80': {
+  'vector-z80color': {
     code_start: 0x0,
-    code_size: 0x4000,
-    data_start: 0x6000,
-    data_size: 0x1000,
+    code_size: 0x8000,
+    data_start: 0xe000,
+    data_size: 0x2000,
   },
 };
 
@@ -650,13 +650,15 @@ function compileSDCC(code, platform) {
     //'--asm=z80asm',
     '--fomit-frame-pointer', '--opt-code-speed',
     '-o', 'main.asm']);
+  /*
   // ignore if all are warnings (TODO?)
   var nwarnings = 0;
   for (var err of msvc_errors) {
     if (err.type && err.type.startsWith("warning"))
       nwarnings++;
   }
-  if (msvc_errors.length && nwarnings < msvc_errors.length) {
+  */
+  if (msvc_errors.length /* && nwarnings < msvc_errors.length*/) {
     return {errors:msvc_errors};
   }
   try {