diff --git a/src/common/emu.ts b/src/common/emu.ts
index 6510b8e9..3ec11ac9 100644
--- a/src/common/emu.ts
+++ b/src/common/emu.ts
@@ -351,11 +351,12 @@ type KeyCodeMap = Map<number,KeyMapEntry>;
 
 export const Keys = {
     ANYKEY:   {c: 0,   n: "?"},
+    // https://w3c.github.io/gamepad/#remapping
     // gamepad and keyboard (player 0)
-    UP:       {c: 38,  n: "Up",    plyr:0, yaxis:-1},
-    DOWN:     {c: 40,  n: "Down",  plyr:0, yaxis:1},
-    LEFT:     {c: 37,  n: "Left",  plyr:0, xaxis:-1},
-    RIGHT:    {c: 39,  n: "Right", plyr:0, xaxis:1},
+    UP:       {c: 38,  n: "Up",    plyr:0, button:12, yaxis:-1},
+    DOWN:     {c: 40,  n: "Down",  plyr:0, button:13, yaxis:1},
+    LEFT:     {c: 37,  n: "Left",  plyr:0, button:14, xaxis:-1},
+    RIGHT:    {c: 39,  n: "Right", plyr:0, button:15, xaxis:1},
     A:        {c: 32,  n: "Space", plyr:0, button:0},
     B:        {c: 16,  n: "Shift", plyr:0, button:1},
     GP_A:     {c: 88,  n: "X",     plyr:0, button:0},
@@ -366,10 +367,10 @@ export const Keys = {
     START:    {c: 13,  n: "Enter", plyr:0, button:9},
     OPTION:   {c: 8,   n: "Bcksp", plyr:0, button:10},
     // gamepad and keyboard (player 1)
-    P2_UP:       {c: 87, n: "W",  plyr:1, yaxis:-1},
-    P2_DOWN:     {c: 83, n: "S",  plyr:1, yaxis:1},
-    P2_LEFT:     {c: 65, n: "A",  plyr:1, xaxis:-1},
-    P2_RIGHT:    {c: 68, n: "D",  plyr:1, xaxis:1},
+    P2_UP:       {c: 87, n: "W",  plyr:1, button:12, yaxis:-1},
+    P2_DOWN:     {c: 83, n: "S",  plyr:1, button:13, yaxis:1},
+    P2_LEFT:     {c: 65, n: "A",  plyr:1, button:14, xaxis:-1},
+    P2_RIGHT:    {c: 68, n: "D",  plyr:1, button:15, xaxis:1},
     P2_A:        {c: 84, n: "T",  plyr:1, button:0},
     P2_B:        {c: 82, n: "R",  plyr:1, button:1},
     P2_GP_A:     {c: 69, n: "E",  plyr:1, button:0},
diff --git a/src/machine/arm32.ts b/src/machine/arm32.ts
index 00b70392..e85edc4a 100644
--- a/src/machine/arm32.ts
+++ b/src/machine/arm32.ts
@@ -8,6 +8,8 @@ import { hex, lpad } from "../common/util";
 var GBA_KEYCODE_MAP = makeKeycodeMap([
   [Keys.A,     0, 0x1],
   [Keys.B,     0, 0x2],
+  [Keys.GP_A,  0, 0x1],
+  [Keys.GP_B,  0, 0x2],
   [Keys.SELECT,0, 0x4],
   [Keys.START ,0, 0x8],
   [Keys.RIGHT, 0, 0x10],
diff --git a/src/machine/atari7800.ts b/src/machine/atari7800.ts
index ec61f81c..306508d1 100644
--- a/src/machine/atari7800.ts
+++ b/src/machine/atari7800.ts
@@ -42,6 +42,8 @@ const INPT0 = 8;
 const Atari7800_KEYCODE_MAP = makeKeycodeMap([
   [Keys.A,        INPT0+0, 0x80],
   [Keys.B,        INPT0+1, 0x80],
+  [Keys.GP_A,     INPT0+0, 0x80],
+  [Keys.GP_B,     INPT0+1, 0x80],
   [Keys.SELECT,   SWCHB, -0x02],
   [Keys.START,    SWCHB, -0x01],
   [Keys.UP,       SWCHA, -0x10],
diff --git a/src/machine/coleco.ts b/src/machine/coleco.ts
index 99b42ec1..cd759f8d 100644
--- a/src/machine/coleco.ts
+++ b/src/machine/coleco.ts
@@ -32,6 +32,8 @@ var COLECOVISION_KEYCODE_MAP = makeKeycodeMap([
   [Keys.RIGHT, 0, 0x2],
   [Keys.A, 0, 0x40],
   [Keys.B, 1, 0x40],
+  [Keys.GP_A, 0, 0x40],
+  [Keys.GP_B, 1, 0x40],
 
   [Keys.P2_UP, 2, 0x1],
   [Keys.P2_DOWN, 2, 0x4],
diff --git a/src/machine/sms.ts b/src/machine/sms.ts
index 3872cbed..9c1cd720 100644
--- a/src/machine/sms.ts
+++ b/src/machine/sms.ts
@@ -18,6 +18,8 @@ var SG1000_KEYCODE_MAP = makeKeycodeMap([
   [Keys.RIGHT, 0, 0x8],
   [Keys.A,     0, 0x10],
   [Keys.B,     0, 0x20],
+  [Keys.GP_A,  0, 0x10],
+  [Keys.GP_B,  0, 0x20],
 
   [Keys.P2_UP,    0, 0x40],
   [Keys.P2_DOWN,  0, 0x80],
diff --git a/src/platform/nes.ts b/src/platform/nes.ts
index 6fab6bd4..39f471b5 100644
--- a/src/platform/nes.ts
+++ b/src/platform/nes.ts
@@ -50,6 +50,8 @@ const JSNES_PRESETS = [
 const JSNES_KEYCODE_MAP = makeKeycodeMap([
   [Keys.A,        0, 0],
   [Keys.B,        0, 1],
+  [Keys.GP_A,     0, 0],
+  [Keys.GP_B,     0, 1],
   [Keys.SELECT,   0, 2],
   [Keys.START,    0, 3],
   [Keys.UP,       0, 4],