diff --git a/Source/HBIOS/ide.asm b/Source/HBIOS/ide.asm
index 9c05c54c..f43e4468 100644
--- a/Source/HBIOS/ide.asm
+++ b/Source/HBIOS/ide.asm
@@ -1246,19 +1246,31 @@ IDE_INITDEV00:
 	CALL	DUMP_BUFFER		; DUMP IT IF DEBUGGING
 #ENDIF
 ;
-	XOR	A
 	LD	(IY+IDE_MED),0		; CLEAR FLAGS
-
-	; DETERMINE IF CF DEVICE
-	LD	HL,HB_WRKBUF		; FIRST WORD OF IDENTIFY DATA HAS CF FLAG
-	LD	A,$8A			; FIRST BYTE OF MARKER IS $8A
-	CP	(HL)			; COMPARE
-	JR	NZ,IDE_INITDEV1		; IF NO MATCH, NOT CF
-	INC	HL
-	LD	A,$84			; SECOND BYTE OF MARKER IS $84
-	CP	(HL)			; COMPARE
-	JR	NZ,IDE_INITDEV1		; IF NOT MATCH, NOT CF
-	SET	0,(IY+IDE_MED)		; SET FLAGS BIT FOR CF MEDIA
+;
+	; DETERMINE IF CF DEVICE BY TESTING FOR CF CARD SIGNATURES
+	; IN THEORY, THERE ARE SOME OTHER POSSIBLE VARIATIONS, BUT
+	; THEY ARE NOT RECOMMENDED BY THE CF CARD SPEC AND MIGHT
+	; OVERLAP WITH "REAL" HARD DISK SIGNATURES.  I HAVE NEVER
+	; SEEN A CF CARD THAT DID NOT USE ONE OF THE BELOW.
+	; CREDIT TO LASZLO SZOLNOKI 
+	LD	BC,$848A		; STANDARD CF CARD SIGNATURE
+	CALL	IDE_INITDEV000		; TEST & SET
+	LD	BC,$044A		; ALT SIG FOR NON-REMOVABLE
+	CALL	IDE_INITDEV000		; TEST & SET
+	LD	BC,$0040		; ALT SIG FOR NON-REMOVABLE
+	CALL	IDE_INITDEV000		; TEST & SET
+	JR	IDE_INITDEV1		; CONTINUE INIT
+;
+IDE_INITDEV000:
+	; CHECK IF FIRST WORD OF IDENTIFY DATA MATCHES VALUE IN BC
+	; AND SET CF FLAG IF SO
+	LD	HL,(HB_WRKBUF)		; FIRST WORD OF IDENTIFY DATA
+	OR	A			; CLEAR CARRY
+	SBC	HL,BC			; COMPARE
+	RET	NZ			; ABORT IF NOT EQUAL
+	SET	0,(IY+IDE_MED)		; ELSE SET FLAGS BIT FOR CF MEDIA
+	RET				; AND RETURN
 ;
 IDE_INITDEV1:
 	; DETERMINE IF LBA CAPABLE
diff --git a/Source/HBIOS/ppide.asm b/Source/HBIOS/ppide.asm
index 13c536f1..2b18f519 100644
--- a/Source/HBIOS/ppide.asm
+++ b/Source/HBIOS/ppide.asm
@@ -1273,16 +1273,29 @@ PPIDE_INITDEV00:
 ;
 	LD	(IY+PPIDE_MED),0	; CLEAR MEDIA FLAGS
 ;
-	; DETERMINE IF CF DEVICE
-	LD	HL,HB_WRKBUF		; FIRST WORD OF IDENTIFY DATA HAS CF FLAG
-	LD	A,$8A			; FIRST BYTE OF MARKER IS $8A
-	CP	(HL)			; COMPARE
-	JR	NZ,PPIDE_INITDEV1	; IF NO MATCH, NOT CF
-	INC	HL
-	LD	A,$84			; SECOND BYTE OF MARKER IS $84
-	CP	(HL)			; COMPARE
-	JR	NZ,PPIDE_INITDEV1	; IF NOT MATCH, NOT CF
-	SET	0,(IY+PPIDE_MED)	; SET FLAGS BIT FOR CF MEDIA
+	; DETERMINE IF CF DEVICE BY TESTING FOR CF CARD SIGNATURES
+	; IN THEORY, THERE ARE SOME OTHER POSSIBLE VARIATIONS, BUT
+	; THEY ARE NOT RECOMMENDED BY THE CF CARD SPEC AND MIGHT
+	; OVERLAP WITH "REAL" HARD DISK SIGNATURES.  I HAVE NEVER
+	; SEEN A CF CARD THAT DID NOT USE ONE OF THE BELOW.
+	; CREDIT TO LASZLO SZOLNOKI 
+	LD	BC,$848A		; STANDARD CF CARD SIGNATURE
+	CALL	PPIDE_INITDEV000	; TEST & SET
+	LD	BC,$044A		; ALT SIG FOR NON-REMOVABLE
+	CALL	PPIDE_INITDEV000	; TEST & SET
+	LD	BC,$0040		; ALT SIG FOR NON-REMOVABLE
+	CALL	PPIDE_INITDEV000	; TEST & SET
+	JR	PPIDE_INITDEV1		; CONTINUE INIT
+;
+PPIDE_INITDEV000:
+	; CHECK IF FIRST WORD OF IDENTIFY DATA MATCHES VALUE IN BC
+	; AND SET CF FLAG IF SO
+	LD	HL,(HB_WRKBUF)		; FIRST WORD OF IDENTIFY DATA
+	OR	A			; CLEAR CARRY
+	SBC	HL,BC			; COMPARE
+	RET	NZ			; ABORT IF NOT EQUAL
+	SET	0,(IY+PPIDE_MED)	; ELSE SET FLAGS BIT FOR CF MEDIA
+	RET				; AND RETURN
 ;
 PPIDE_INITDEV1:
 	; DETERMINE IF LBA CAPABLE
diff --git a/Source/ver.inc b/Source/ver.inc
index f92228a4..90b2cbf3 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.177"
+#DEFINE BIOSVER	"3.1.1-pre.178"
diff --git a/Source/ver.lib b/Source/ver.lib
index e720a560..0814c961 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.177"
+	db	"3.1.1-pre.178"
 	endm