diff --git a/armsrc/apps.h b/armsrc/apps.h
index 087abd0a6..59be5f118 100644
--- a/armsrc/apps.h
+++ b/armsrc/apps.h
@@ -100,6 +100,7 @@ void SetAdcMuxFor(uint32_t whichGpio);
 #define FPGA_HF_SIMULATOR_NO_MODULATION				(0<<0)
 #define FPGA_HF_SIMULATOR_MODULATE_BPSK				(1<<0)
 #define FPGA_HF_SIMULATOR_MODULATE_212K				(2<<0)
+#define FPGA_HF_SIMULATOR_MODULATE_424K				(4<<0)
 // Options for ISO14443A
 #define FPGA_HF_ISO14443A_SNIFFER					(0<<0)
 #define FPGA_HF_ISO14443A_TAGSIM_LISTEN				(1<<0)
diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index 7474598b6..7289abbc2 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -1090,6 +1090,12 @@ int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived)
 	CodeIClassTagAnswer(response4, sizeof(response4));
 	memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
 
+
+	// Start from off (no field generated)
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	SpinDelay(200);
+
+
 	// We need to listen to the high-frequency, peak-detected path.
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 	FpgaSetupSsc();
@@ -1107,11 +1113,17 @@ int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived)
 		displayDebug = true;
 
 		LED_B_OFF();
+		//Signal tracer
+		// Can be used to get a trigger for an oscilloscope..
+		LED_C_OFF();
+
 		if(!GetIClassCommandFromReader(receivedCmd, &len, 100)) {
 			buttonPressed = true;
 			break;
 		}
 		r2t_time = GetCountSspClk();
+		//Signal tracer
+		LED_C_ON();
 
 		// Okay, look at the command now.
 		if(receivedCmd[0] == 0x0a ) {
@@ -1236,41 +1248,34 @@ int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived)
 
 static int SendIClassAnswer(uint8_t *resp, int respLen, int delay)
 {
-	int i = 0, u = 0, d = 0;
+	int i = 0, d=0;//, u = 0, d = 0;
 	uint8_t b = 0;
-	// return 0;
-	// Modulate Manchester
-	// FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD424);
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR|FPGA_HF_SIMULATOR_MODULATE_424K);
+
 	AT91C_BASE_SSC->SSC_THR = 0x00;
 	FpgaSetupSsc();
-	
-	// send cycle
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			(void)b;
+	while(!BUTTON_PRESS()) {
+		if((AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)){
+			b = AT91C_BASE_SSC->SSC_RHR; (void) b;
 		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)){
+			b = 0x00;
 			if(d < delay) {
-				b = 0x00;
 				d++;
 			}
-			else if(i >= respLen) {
-				b = 0x00;
-				u++;
-			} else {
-				b = resp[i];
-				u++;
-				if(u > 1) { i++; u = 0; }
+			else {
+				if( i < respLen){
+					b = resp[i];
+					//Hack
+					//b = 0xAC;
+				}
+				i++;
 			}
 			AT91C_BASE_SSC->SSC_THR = b;
+		}
 
-			if(u > 4) break;
-		}
-		if(BUTTON_PRESS()) {
-			break;
-		}
+		if (i > respLen +4) break;
 	}
 
 	return 0;
@@ -1284,7 +1289,6 @@ static int SendIClassAnswer(uint8_t *resp, int respLen, int delay)
 static void TransmitIClassCommand(const uint8_t *cmd, int len, int *samples, int *wait)
 {
   int c;
-
   FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
   AT91C_BASE_SSC->SSC_THR = 0x00;
   FpgaSetupSsc();
@@ -1360,12 +1364,12 @@ void CodeIClassCommand(const uint8_t * cmd, int len)
     b = cmd[i];
     for(j = 0; j < 4; j++) {
       for(k = 0; k < 4; k++) {
-	if(k == (b & 3)) {
-	    ToSend[++ToSendMax] = 0x0f;
-	}
-	else {
-	    ToSend[++ToSendMax] = 0x00;
-	}
+			if(k == (b & 3)) {
+				ToSend[++ToSendMax] = 0x0f;
+			}
+			else {
+				ToSend[++ToSendMax] = 0x00;
+			}
       }
       b >>= 2;
     }
diff --git a/fpga/fpga.bit b/fpga/fpga.bit
index e773ef932..e5ea4fcd3 100644
Binary files a/fpga/fpga.bit and b/fpga/fpga.bit differ
diff --git a/fpga/hi_simulate.v b/fpga/hi_simulate.v
index efaf452fa..c04ade80b 100644
--- a/fpga/hi_simulate.v
+++ b/fpga/hi_simulate.v
@@ -89,7 +89,9 @@ always @(mod_type or ssp_clk or ssp_dout)
     else if(mod_type == 3'b001)
         modulating_carrier <= ssp_dout ^ ssp_clk_divider[3]; // XOR means BPSK
     else if(mod_type == 3'b010)
-        modulating_carrier <= ssp_dout & ssp_clk_divider[5]; // switch 212kHz subcarrier on/off
+	modulating_carrier <= ssp_dout & ssp_clk_divider[5]; // switch 212kHz subcarrier on/off
+    else if(mod_type == 3'b100)
+	modulating_carrier <= ssp_dout & ssp_clk_divider[4]; // switch 424kHz modulation on/off
     else
         modulating_carrier <= 1'b0;                           // yet unused
 
@@ -105,5 +107,8 @@ assign pwr_oe4 = modulating_carrier;
 assign pwr_oe3 = 1'b0;
 
 assign dbg = after_hysteresis;
+//reg dbg;
+//always @(ssp_dout)
+//    dbg <= ssp_dout;
 
 endmodule