diff --git a/Source/HBIOS/md.asm b/Source/HBIOS/md.asm
index f5a161e7..9c26c860 100644
--- a/Source/HBIOS/md.asm
+++ b/Source/HBIOS/md.asm
@@ -601,15 +601,19 @@ MDSTR_LEN	.TEXT	"LEN=$"
 ;	THE STACK IS IN UPPER MEMORY DURING BIOS INITIALIZATION BUT IS IN LOWER
 ;	MEMORY DURING HBIOS CALLS.
 ;
-;	TO ACCESS THE FLASH CHIP FEATURES, CODE IS COPIED TO THE UPPER RAM BANK 
+;	TO ACCESS THE FLASH CHIP FEATURES, CODE IS COPIED TO THE UPPER RAM BANK (HBX_BUF)
 ;	AND THE FLASH CHIP IS SWITCHED INTO THE LOWER BANK.
 ;
+;	EACH FLASH ROUTINE MUST FIT INTO TO THE HBX_BUF, INCLUDING IT'S LOCAL STACK WHICH
+;	IS REQUIRED FOR CALLING THE BANK SWITCH ROUTINES. IN SOME CASES THIS MEANS
+;	OVERLAYING THE STACK ON THE INITIALIZATION CODE.
+;
 ;	INSPIRED BY WILL SOWERBUTTS FLASH4 UTILITY - https://github.com/willsowerbutts/flash4/
 ;
 ;==================================================================================================
 ;
 #IF (MDFFENABLE)
-FF_TGT		.EQU	0BFB7H		; TARGET CHIP FOR R/W FILESYSTEM
+FF_TGT		.EQU	0B7BFH		; TARGET CHIP FOR R/W FILESYSTEM
 ;
 ;======================================================================
 ; BIOS FLASH INITIALIZATION
@@ -646,9 +650,9 @@ FF_PROBE:
 
 	PUSH	HL
 ;	PUSH	DE
-	LD	H,FF_TGT&$FF		; IF WE MATCH WITH
-	LD	L,FF_TGT/$FF
-	CCF			; A NON 39SF040
+	LD	HL,FF_TGT		; IF WE MATCH WITH
+;	LD	L,FF_TGT&$FF
+	XOR	A			; A NON 39SF040
 	SBC	HL,BC			; CHIP SET THE
 	LD	A,(MD_FFSEN)		; R/W FLAG TO R/O
 	OR	H
@@ -772,6 +776,52 @@ FF_FNCALL:				; USING HBX_BUF FOR CODE AREA
 	RET				; RETURN TO MD_READF, MD_WRITEF
 ;
 ;======================================================================
+; CALCULATE BANK AND ADDRESS DATA FROM MEMORY ADDRESS
+;
+; ON ENTRY DE:HL CONTAINS 32 BIT MEMORY ADDRESS.
+; ON EXIT  I,B   CONTAINS BANK SELECT BYTE
+;          Y,C   CONTAINS HIGH BYTE OF SECTOR ADDRESS
+;          A     CONTAINS CURRENT BANK HB_CURBNK
+;
+; DDDDDDDDEEEEEEEE HHHHHHHHLLLLLLLL
+; 3322222222221111 1111110000000000
+; 1098765432109876 5432109876543210
+; XXXXXXXXXXXXSSSS SSSSXXXXXXXXXXXX < S = SECTOR
+; XXXXXXXXXXXXBBBB BXXXXXXXXXXXXXXX < B = BANK
+;======================================================================
+;
+FF_CALCA:
+;
+#IF (MD_FDBG==1)
+	CALL	PC_SPACE	; DISPLAY SECTOR
+	CALL	PRTHEX32	; SECTOR ADDRESS 
+	CALL	PC_SPACE	; IN DE:HL
+#ENDIF
+;
+	LD	A,E		; BOTTOM PORTION OF SECTOR
+	AND	$0F		; ADDRESS THAT GETS WRITTEN
+	RLC	H		; WITH ERASE COMMAND BYTE
+	RLA			; A15 GETS DROPPED OFF AND
+	LD	B,A		; ADDED TO BANK SELECT
+;
+	LD	A,H		; TOP SECTION OF SECTOR
+	RRA			; ADDRESS THAT GETS WRITTEN
+	AND	$70		; TO BANK SELECT PORT
+	LD	C,A
+;
+	PUSH	BC
+	POP	IY
+;
+#IF (MD_FDBG==1)
+	CALL	PRTHEXWORD	; DISPLAY BANK AND
+	CALL	PC_SPACE	; SECTOR RESULT
+#ENDIF
+;
+	LD	A,(HB_CURBNK)	; WE ARE STARTING IN HB_CURBNK
+;
+	RET
+;
+;======================================================================
 ; IDENTIFY FLASH CHIP. 
 ;  CALCULATE BANK AND ADDRESS DATA FROM ENTRY ADDRESS
 ;  CREATE A CODE BUFFER IN HIGH MEMORY AREA
@@ -842,53 +892,7 @@ MD_FIDENT_R:				; THIS CODE GETS RELOCATED TO HIGH MEMORY
 	.FILL	8,0			; STACK SPACE
 MD_FIST	.DW	0			; SAVE STACK
 MD_I_SZ	.EQU	$-MD_FIDENT_R		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
-;
-;======================================================================
-; CALCULATE BANK AND ADDRESS DATA FROM MEMORY ADDRESS
-;
-; ON ENTRY DE:HL CONTAINS 32 BIT MEMORY ADDRESS.
-; ON EXIT  I,B   CONTAINS BANK SELECT BYTE
-;          Y,C   CONTAINS HIGH BYTE OF SECTOR ADDRESS
-;          A     CONTAINS CURRENT BANK HB_CURBNK
-;
-; DDDDDDDDEEEEEEEE HHHHHHHHLLLLLLLL
-; 3322222222221111 1111110000000000
-; 1098765432109876 5432109876543210
-; XXXXXXXXXXXXSSSS SSSSXXXXXXXXXXXX < S = SECTOR
-; XXXXXXXXXXXXBBBB BXXXXXXXXXXXXXXX < B = BANK
-;======================================================================
-;
-FF_CALCA:
-;
-#IF (MD_FDBG==1)
-	CALL	PC_SPACE	; DISPLAY SECTOR
-	CALL	PRTHEX32	; SECTOR ADDRESS 
-	CALL	PC_SPACE	; IN DE:HL
-#ENDIF
-;
-	LD	A,E		; BOTTOM PORTION OF SECTOR
-	AND	$0F		; ADDRESS THAT GETS WRITTEN
-	RLC	H		; WITH ERASE COMMAND BYTE
-	RLA			; A15 GETS DROPPED OFF AND
-	LD	B,A		; ADDED TO BANK SELECT
-;
-	LD	A,H		; TOP SECTION OF SECTOR
-	RRA			; ADDRESS THAT GETS WRITTEN
-	AND	$70		; TO BANK SELECT PORT
-	LD	C,A
-;
-	PUSH	BC
-	POP	IY
-;
-#IF (MD_FDBG==1)
-	CALL	PRTHEXWORD	; DISPLAY BANK AND
-	CALL	PC_SPACE	; SECTOR RESULT
-#ENDIF
-;
-	LD	A,(HB_CURBNK)	; WE ARE STARTING IN HB_CURBNK
-;
-	RET
-;
+
 ;======================================================================
 ; ERASE FLASH SECTOR
 ;
@@ -924,58 +928,34 @@ MD_FERAS:
 ;
 ; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
 ;          A  CONTAINS CURRENT BANK 
-; ON EXIT  A  RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+; ON EXIT  A  RETURNS STATUS FLASH 0=SUCCESS FAIL=NZ
 ;======================================================================
 ;
 MD_FERAS_R:				; THIS CODE GETS RELOCATED TO HIGH MEMORY
 ;
-	LD	(HBX_BUF+MD_FEST-MD_FERAS_R),SP		; SAVE STACK
-	LD	SP,HBX_BUF + (MD_FERAS_S-MD_FERAS_R)	; SETUP TEMP STACK
+MD_FEST	.EQU	$+2			; SAVE STACK
+;
+	LD	HL,$5555				; COMMAND		; LOCAL STACK
+	LD	DE,$2AAA				; PRELOAD		; LOCAL STACK
+	LD	(HBX_BUF+MD_FEST-MD_FERAS_R),SP		; SAVE STACK		; LOCAL STACK
+	LD	SP,HBX_BUF + (MD_FERAS_S-MD_FERAS_R)	; SETUP TEMP STACK	; LOCAL STACK
 ;
-	LD	HL,$5555		; LD	A,$AA			; COMMAND
-	LD	DE,$2AAA	;+3
 MD_FERAS_S
 	PUSH	AF			; SAVE CURRENT BANK
 	LD	A,B			; SELECT BANK
 	CALL	HBX_BNKSEL		; TO PROGRAM
-					;
-;	LD	HL,$5555		; LD	A,$AA			; COMMAND
-;	LD	A,L			; LD	($5555),A		; SETUP	
-;	LD	(HL),$AA		; LD	A,$55
-;	LD	($2AAA),A		; LD	($2AAA),A
-;	LD	(HL),$80		; LD	A,$80
-;	LD	(HL),$AA		; LD	($5555),A
-;	LD	($2AAA),A		; LD	A,$AA
-					; LD	($5555),A
-					; LD	A,$55
-					; LD	($2AAA),A
 ;
-;	LD	HL,$5555		; LD	A,$AA			; COMMAND
-;	LD	DE,$2AAA	;+3
-;	LD	A,L			; LD	($5555),A		; SETUP	
-;	LD	(HL),$AA		; LD	A,$55
-;	LD	(DE),A		;-2	; LD	($2AAA),A
-;	LD	(HL),$80		; LD	A,$80
-;	LD	(HL),$AA		; LD	($5555),A
-;	LD	(DE),A		;-2	; LD	A,$AA
-					; LD	($5555),A
-					; LD	A,$55
-					; LD	($2AAA),A
-;
-;	LD	HL,$5555		; LD	A,$AA			; COMMAND
-;	LD	DE,$2AAA	;+3
-	LD	A,L			; LD	($5555),A		; SETUP	
-	LD	(HL),E		;-1	; LD	A,$55
-	LD	(DE),A		;-2	; LD	($2AAA),A
+
+	LD	A,L			; LD	($5555),A		; COMMAND
+	LD	(HL),E			; LD	A,$55			; SETUP
+	LD	(DE),A			; LD	($2AAA),A
 	LD	(HL),$80		; LD	A,$80
-	LD	(HL),E		;-1	; LD	($5555),A
-	LD	(DE),A		;-2	; LD	A,$AA
+	LD	(HL),E			; LD	($5555),A
+	LD	(DE),A			; LD	A,$AA
 					; LD	($5555),A
 					; LD	A,$55
 					; LD	($2AAA),A
 
-
-
 	LD	H,C			; SECTOR 
 	LD	L,$00			; ADDRESS
 ;
@@ -999,11 +979,11 @@ FF_WT4:	LD	C,(HL)			; FROM THE SAME FLASH ADDRESS.
 	BIT	6,A			; IF THEY ARE THEN OPERATION WAS COMPLETED					
 	JR	Z,FF_WT5		; OTHERWISE ERASE OPERATION FAILED OR TIMED OUT.
 ;
-;	LD	(HL),$F0		; WRITE DEVICE RESET
-;	LD	C,$FF			; SET FAIL STATUS
+	LD	C,$F0			; COMMON FAIL STATUS / PREPARE DEVICE RESET CODE
+	LD	(HL),C			; WRITE DEVICE RESET
 	JR	FF_WT6
-;
 FF_WT5:	LD	C,L			; SET SUCCESS STATUS
+;
 FF_WT6:	POP	AF			; RETURN TO ORIGINAL BANK
 	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
 ;
@@ -1011,7 +991,6 @@ FF_WT6:	POP	AF			; RETURN TO ORIGINAL BANK
 ;
 	RET
 ;
-MD_FEST	.DW	0
 MD_S_SZ	.EQU	$-MD_FERAS_R		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
 ;
 ;======================================================================
@@ -1054,7 +1033,7 @@ MD_FREAD:
 ;          DESTINATION BANK IS ALWAYS CURRENT BANK
 ;
 ; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
-;          DE = 0000
+;          DE = 0000 BYTE COUNT
 ;          IX POINTS TO DATA TO BE WRITTEN
 ;          A  CONTAINS CURRENT BANK 
 ; ON EXIT  NO STATUS RETURNED
@@ -1062,14 +1041,11 @@ MD_FREAD:
 ;
 MD_FREAD_R:				; THIS CODE GETS RELOCATED TO HIGH MEMORY
 ;
-	LD	H,C			; SECTOR
-	LD	L,$00			; ADDRESS
-;	LD	D,L			; INITIALIZE 
-;	LD	E,L			; BYTE COUNT
-;
-	LD	(HBX_BUF+MD_FRST-MD_FREAD_R),SP			; SAVE STACK	
+	LD	H,C			; SECTOR				; LOCAL STACK
+	LD	L,D			; ADDRESS				; LOCAL	STACK
+	LD	(HBX_BUF+MD_FRST-MD_FREAD_R),SP		; SAVE STACK		; LOCAL STACK
+	LD	SP,HBX_BUF + (MD_FRD_S-MD_FREAD_R)	; SETUP TEMP STACK	; LOCAL STACK
 MD_FRD_S:
-	LD	SP,HBX_BUF + (MD_FRD_S-MD_FREAD_R)		; SETUP TEMP STACK
 ;
 	PUSH	AF			; SAVE CURRENT BANK
 ;
@@ -1092,7 +1068,6 @@ MD_FRD1:
 
 	POP	AF			; RETURN TO ORIGINAL BANK
 	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
-;	LD	C,D			; RETURN STATUS
 ;
 	LD	SP,(HBX_BUF+MD_FRST-MD_FREAD_R)		; RESTORE STACK
 ;
@@ -1141,6 +1116,7 @@ MD_FWRIT:
 ;
 ; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
 ;          IX POINTS TO DATA TO BE WRITTEN
+;          DE = 0000 BYTE COUNT
 ;          A  CONTAINS CURRENT BANK 
 ; ON EXIT  A  RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
 ;======================================================================
@@ -1149,13 +1125,10 @@ MD_FWRIT_R:				; THIS CODE GETS RELOCATED TO HIGH MEMORY
 ;
 MD_FWST	.EQU	$+2			; SAVE STACK
 ;
-	LD	H,C			; SECTOR
-	LD	L,$00			; ADDRESS
-;	LD	D,L			; INITIALIZE 
-;	LD	E,L			; BYTE COUNT
-
-	LD	(HBX_BUF+MD_FWST-MD_FWRIT_R),SP	; SAVE STACK
-	LD	SP, HBX_BUF+(MD_FWRIT_S-MD_FWRIT_R)		; SETUP TEMP STACK
+	LD	H,C			; SECTOR				; LOCAL STACK
+	LD	L,D			; ADDRESS				; LOCAL STACK
+	LD	(HBX_BUF+MD_FWST-MD_FWRIT_R),SP		; SAVE STACK		; LOCAL STACK
+	LD	SP, HBX_BUF+(MD_FWRIT_S-MD_FWRIT_R)	; SETUP TEMP STACK	; LOCAL STACK
 MD_FWRIT_S:
 ;
 	PUSH	AF			; SAVE CURRENT BANK
@@ -1253,7 +1226,7 @@ MD_FFSEN	.DB	00h		; FLASH FILES SYSTEM ENABLE
 ;
 ;======================================================================
 ;
-#IF (MD_FDBG==1)
+#IF (MD_FDBG==0)
 		.ECHO	"MD_FIDENT_R "
 		.ECHO	MD_I_SZ
 		.ECHO	"\n"