diff --git a/source/disc_io/io_scsd.c b/source/disc_io/io_scsd.c
index 9a024d0..76f107d 100644
--- a/source/disc_io/io_scsd.c
+++ b/source/disc_io/io_scsd.c
@@ -83,17 +83,8 @@ static u32 _SCSD_relativeCardAddress = 0;	// Preshifted Relative Card Address
 
 extern bool _SCSD_writeData_s (u8 *data, u16* crc);
 
-static bool _SCSD_unlock (void) {
-	//see if we can write to SCSD RAM
-	vu32 *ramPointer = (u32*)0x08000000;
-	_SC_changeMode (SC_MODE_RAM);
-	*ramPointer = 0x5555aaaa;
-	*ramPointer = ~*ramPointer;
-	if(*ramPointer != 0xaaaa5555) {
-		return false;
-	}
+static inline void _SCSD_unlock (void) {
 	_SC_changeMode (SC_MODE_MEDIA);	
-	return true;
 }
 
 static bool _SCSD_sendCommand (u8 command, u32 argument) {
@@ -273,9 +264,7 @@ static bool _SCSD_readData (void* buffer) {
 // Functions needed for the external interface
 
 bool _SCSD_startUp (void) {
-	if (!_SCSD_unlock()) {
-		return false;
-	}
+	_SCSD_unlock();
 	return _SCSD_initCard();
 }
 
diff --git a/source/disc_io/io_sd_common.c b/source/disc_io/io_sd_common.c
index 0a38e62..24f6873 100644
--- a/source/disc_io/io_sd_common.c
+++ b/source/disc_io/io_sd_common.c
@@ -33,6 +33,9 @@
 	2006-08-07 - Chishm
 		* Moved the SD initialization to a common function
 		* Increased timeouts for slower cards
+		
+	2006-08-08 - Chishm
+		* Init aborts when it doesn't get a valid response to APP_CMD - speeds up detection when no card is inserted
 */
 
 #include "io_sd_common.h"
@@ -146,6 +149,10 @@ bool _SD_InitCard (_SD_FN_CMD_6BYTE_RESPONSE cmd_6byte_response,
 	
 	for (i = 0; i < MAX_STARTUP_TRIES ; i++) {
 		cmd_6byte_response (responseBuffer, APP_CMD, 0);
+		// Check that the card gave the correct response
+		if (responseBuffer[0] != APP_CMD) {
+			return false;
+		}
 		if ( 
 			cmd_6byte_response (responseBuffer, SD_APP_OP_COND, SD_OCR_VALUE) &&
 			((responseBuffer[1] & 0x80) != 0))