diff --git a/Source/HBIOS/md.asm b/Source/HBIOS/md.asm
index 5675df72..23cbb20d 100644
--- a/Source/HBIOS/md.asm
+++ b/Source/HBIOS/md.asm
@@ -27,6 +27,7 @@ MD_AFSH		.EQU	%00111000	; FLASH ATTRIBUTE
 ;
 MD_FDBG		.EQU	0		; FLASH DEBUG CODE
 MD_FVBS		.EQU	1		; FLASH VERBOSE OUTPUT
+MD_FVAR		.EQU	1		; FLASH VERIFY AFTER WRITE
 ;
 ; DEVICE CONFIG TABLE (RAM DEVICE FIRST TO MAKE IT ALWAYS FIRST DRIVE)
 ;
@@ -54,7 +55,7 @@ MD_CFGTBL:
 ;
 MD_INIT:
 #IF (MDFFENABLE)
-	CALL	MD_FINIT			; PROBE FLASH CAPABILITY
+	CALL	MD_FINIT		; PROBE FLASH CAPABILITY
 #ENDIF
 
 	CALL	NEWLINE			; FORMATTING
@@ -411,7 +412,26 @@ MD_SECM1:				; DESIRED SECTOR IS IN BUFFER
 	LD	BC,MD_FWRIT_R		; PUT ROUTINE TO CALL
 	CALL	FF_FNCALL		; EXECUTE: WRITE 4K SECTOR
 ;
-	XOR	A
+	XOR	A			; PRESUME SUCCESS STATUS
+;
+#IF (MD_FVAR==1)
+	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS
+	LD	BC,MD_FVERI_R		; PUT ROUTINE TO CALL
+	CALL	FF_FNCALL		; EXECUTE: VERIFY 4K SECTOR
+;
+	OR	A
+	RET	Z			; RETURN IF SUCCESSFUL
+;
+	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS		; RETRY
+	LD	BC,MD_FWRIT_R		; PUT ROUTINE TO CALL		; WRITE
+	CALL	FF_FNCALL		; EXECUTE: WRITE 4K SECTOR	; ONCE
+;
+	LD	IX,MD_F4KBUF		; SET SOURCE ADDRESS		; VERIFY
+	LD	BC,MD_FVERI_R		; PUT ROUTINE TO CALL		; AGAIN
+	CALL	FF_FNCALL		; EXECUTE: VERIFY 4K SECTOR
+;
+	OR	A			; SET FINAL STATUS AFTER RETRY
+#ENDIF
 ;
 	RET
 ;
@@ -754,7 +774,12 @@ FF_NXT2:
 ;   ON ENTRY DE:HL POINTS TO A 32 BIT MEMORY ADDRESS.
 ;            IX    POINTS TO WHERE TO SAVE DATA
 ;   ON EXIT  A     NO STATUS IS RETURNED
-
+;
+;  MD_VERI_R - VERIFY FLASH SECTOR
+;   ON ENTRY DE:HL POINTS TO A 32 BIT MEMORY ADDRESS.
+;            IX    POINTS TO DATA TO COMPARE.
+;   ON EXIT  A     RETURNS STATUS 0=SUCCESS NZ=FAIL
+;
 ;  MD_FWRIT_R - WRITE FLASH SECTOR   
 ;   ON ENTRY DE:HL POINTS TO A 32 BIT MEMORY ADDRESS.
 ;            IX    POINTS TO DATA TO BE WRITTEN
@@ -1024,6 +1049,65 @@ MD_FRD1:
 ;
 MD_FRST	.DW	0			; SAVE STACK
 MD_R_SZ	.EQU	$-MD_FREAD_R		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
+;======================================================================
+; FLASH VERIFY SECTOR. 
+;
+;  SELECT THE APPROPRIATE BANK / ADDRESS
+;  VERIFY SECTOR OF 4096 BYTES, BYTE AT A TIME
+;  SELECT SOURCE BANK,  READ DATA,
+;	   SELECT DESTINATION BANK, COMPARE DATA
+;          DESTINATION BANK IS ALWAYS CURRENT BANK
+;
+; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
+;          DE = 0000 BYTE COUNT
+;          IX POINTS TO DATA TO BE VERIFIED
+;          A  CONTAINS CURRENT BANK 
+; ON EXIT  NO STATUS RETURNED
+;======================================================================
+;
+MD_FVERI_R:				; THIS CODE GETS RELOCATED TO HIGH MEMORY
+;
+	LD	H,C			; SECTOR				; LOCAL STACK
+	LD	L,D			; ADDRESS				; LOCAL	STACK
+	LD	(HBX_BUF+MD_FVST-MD_FVERI_R),SP		; SAVE STACK		; LOCAL STACK
+	LD	SP,HBX_BUF + (MD_FVE_S-MD_FVERI_R)	; SETUP TEMP STACK	; LOCAL STACK
+MD_FVE_S:
+;
+	PUSH	AF			; SAVE CURRENT BANK
+;
+MD_FVE1:	
+	LD	A,B			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO READ
+	LD	C,(HL)			; READ BYTE
+;
+	POP	AF
+	PUSH	AF			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO WRITE
+;
+	LD	A,C
+	SUB	(IX+0)			; COMPARE BYTE
+	LD	C,A			; SET NON ZERO STATUS
+	JR	NZ,MD_FVE2		; EXIT IF MISMATCH
+;
+	INC	HL			; NEXT SOURCE LOCATION
+	INC	IX			; NEXT DESTINATION LOCATION
+;
+	INC	DE			; CONTINUE READING UNTIL
+	BIT	4,D			; WE HAVE DONE ONE SECTOR
+	JR	Z,MD_FVE1
+;
+	LD	C,E			; SET SUCCESS STATUS = 0
+;
+MD_FVE2:
+	POP	AF			; RETURN TO ORIGINAL BANK
+	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
+;
+	LD	SP,(HBX_BUF+MD_FVST-MD_FVERI_R)		; RESTORE STACK
+;
+	RET
+;
+MD_FVST	.DW	0			; SAVE STACK
+MD_V_SZ	.EQU	$-MD_FVERI_R		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
 ;
 ;======================================================================
 ; FLASH WRITE SECTOR. 
@@ -1156,6 +1240,10 @@ MD_FFSEN	.DB	00h		; FLASH FILES SYSTEM ENABLE
 		.ECHO	"MD_FREAD_R "
 		.ECHO	MD_R_SZ
 		.ECHO	"\n"
+;
+		.ECHO	"MD_VERI_R "
+		.ECHO	MD_V_SZ
+		.ECHO	"\n"
 ;
 		.ECHO	"MD_FERAS_R "
 		.ECHO	MD_S_SZ
@@ -1180,6 +1268,9 @@ MD_CSIZE	.SET	MD_I_SZ
 #IF (MD_R_SZ>MD_CSIZE)
 MD_CSIZE	.SET	MD_R_SZ
 #ENDIF
+#IF (MD_V_SZ>MD_CSIZE)
+MD_CSIZE	.SET	MD_V_SZ
+#ENDIF
 ;
 #IF (MD_CSIZE>HBX_BUFSIZ)
 		.ECHO	"Warning: Flash code exceeds available space by "