diff --git a/Source/HBIOS/flashfs.asm b/Source/HBIOS/flashfs.asm
index baf6af34..b69b557e 100644
--- a/Source/HBIOS/flashfs.asm
+++ b/Source/HBIOS/flashfs.asm
@@ -2,7 +2,10 @@
 ;==================================================================================================
 ;   FLASH DRIVER FOR FLASH & EEPROM PROGRAMMING 
 ;
-;	26 SEP 2020 - CURRENTLY ONLY IMPLEMENTS CHIP IDENTIFICATION -- PHIL SUMMERS
+;	26 SEP 2020 - CHIP IDENTIFICATION IMPLMENTED -- PHIL SUMMERS
+;		    - CHIP ERASE IMPLEMENTED
+;	23 OCT 2020 - SECTOR ERASE IMPLEMENTED
+;	01 NOV 2020 - WRITE SECTOR IMPLEMENTED
 ;==================================================================================================
 ;
 ;	UPPER RAM BANK IS ALWAYS AVAILABLE REGARDLESS OF MEMORY BANK SELECTION. HBX_BNKSEL AND
@@ -12,37 +15,102 @@
 ;
 ;	INSPIRED BY WILL SOWERBUTTS FLASH4 UTILITY - https://github.com/willsowerbutts/flash4/
 ;
+;==================================================================================================
+;
+FF_DBG:	.EQU	0			; DEBUG
+;
+;======================================================================
+; BIOS FLASH INITIALIZATION
+;
+; IDENTIFY AND DISPLAY FLASH CHIPS IN SYSTEM.
+; USES MEMORY SIZE DEFINED BY BUILD CONFIGURATION.
+;======================================================================
+;
+;
 FF_INIT:
-	CALL	NEWLINE			; FORMATTING
-	PRTS("FF: FLASH ID:$")
+	CALL	NEWLINE			; DISLAY NUMBER
+	PRTS("FF: UNITS=$")		; OF UNITS 
+	LD	A,+(ROMSIZE/512)+1	; CONFIGURED FOR.
+	CALL	PRTDECB
+;
+	LD	B,A			; NUMBER OF DEVICES TO PROBE
+	LD	C,$00			; START ADDRESS IS 0000:0000 IN DE:HL
+FF_PROBE:
+	LD	D,$00			; SET ADDRESS IN DE:HL
+	LD	E,C			;
+	LD	H,D			; WE INCREASE E BY $08
+	LD	L,D			; ON EACH CYCLE THROUGH
+;	
+	PUSH	BC
+	CALL	PC_SPACE
+	LD	A,+(ROMSIZE/512)+2
+	SUB	B			; PRINT
+	CALL	PRTDECB			; DEVICE 
+	LD	A,'='			; NUMBER
+	CALL	COUT
+	CALL	FF_IINIT		; GET ID AT THIS ADDRESS
+	CALL	FF_LAND			; LOOKUP AND DISPLAY
+	POP	BC
 ;
-	LD	(FF_STACK),SP		; SAVE STACK
-	LD	HL,(FF_STACK)
-
-	LD	BC,FF_I_SZ		; CODE SIZE REQUIRED
-	CCF				; CREATE A RELOCATABLE
-	SBC	HL,BC			; CODE BUFFER IN THE
-	LD	SP,HL			; STACK AREA
+	LD	A,C			; UPDATE ADDRESS
+	ADD	A,$08			; TO NEXT DEVICE
+	LD	C,A
 ;
-	PUSH	HL			; SAVE THE EXECUTE ADDRESS
-	EX	DE,HL			; PUT EXECUTE / START ADDRESS IN DE
-	LD	HL,FF_IDENT		; COPY OUR RELOCATABLE
-	LDIR				; CODE TO THE BUFFER
+	DJNZ	FF_PROBE		; ALWAYS AT LEAST ONE DEVICE
 ;
-	LD	A,(HB_CURBNK)		; WE ARE STARTING IN HB_CURBNK
-	LD	B,A			; WHICH IS THE RAM COPY OF THE BIOS
-	LD	A,BID_BOOT		; BID_BOOT IS ROM BANK 0
+#IF (FF_DBG==1)
+	CALL	FF_TESTING
+#ENDIF
 ;
-	POP	HL			; CALL OUR RELOCATABLE CODE
-	CALL	JPHL
+	XOR	A			; INIT SUCCEEDED
+	RET
 ;
-	LD	HL,(FF_STACK)		; RESTORE ORIGINAL 
-	LD	SP,HL			; STACK POSITION
+;======================================================================
+; TEST CODE AREA
+;======================================================================
+;
+FF_TESTING:
+;
+#IF (1)
+	LD	DE,$0008		; SET
+	LD	HL,$0000		; ADDRESS
+	CALL	FF_EINIT		; CHIP ERASE
+	CALL	PRTHEXBYTE		; DISPLAY STATUS
+#ENDIF	
+;
+#IF (0)
+	LD	DE,$000A		; SET
+	LD	HL,$8000		; ADDRESS
+	CALL	FF_SINIT		; SECTOR ERASE
+	CALL	PRTHEXBYTE		; DISPLAY STATUS
+#ENDIF
+;
+#IF (1)
+	LD	DE,$000A		; SET DESTINATION
+	LD	HL,$8000		; ADDRESS
+	LD	IX,$F000		; SET SOURCE ADDRESS
+	CALL	FF_WINIT		; WRITE SECTOR
+	CALL	PRTHEXBYTE		; DISPLAY STATUS
+#ENDIF
 ;
+	RET
+;
+;======================================================================
+; LOOKUP AND DISPLAY CHIP
+;
+; ON ENTRY DE CONTAINS CHIP ID
+; ON EXIT  A  CONTAINS STATUS 0=SUCCESS, NZ=NOT IDENTIFIED
+;======================================================================
+;
+FF_LAND:
+;
+#IF (FF_DBG==1)
+	PRTS(" ID:$")
 	LD	H,E
 	LD	L,D
 	CALL	PRTHEXWORDHL		; DISPLAY FLASH ID
 	CALL	PC_SPACE
+#ENDIF
 ;
 	LD	HL,FF_TABLE		; SEARCH THROUGH THE FLASH
 	LD	BC,FF_T_CNT		; TABLE TO FIND A MATCH
@@ -59,9 +127,9 @@ FF_NXT1:LD	A,(HL)
 	INC	HL
 	INC	HL
 	JR	FF_NXT2			; MATCH SO EXIT
-
+;
 FF_NXT0:PUSH	BC			; WE DIDN'T MATCH SO POINT
-	LD	BC,17			; TO THE NEXT TABLE ENTRY
+	LD	BC,FF_T_SZ		; TO THE NEXT TABLE ENTRY
 	ADD	HL,BC
 	POP	BC
 ;
@@ -73,79 +141,562 @@ FF_NXT0:PUSH	BC			; WE DIDN'T MATCH SO POINT
 	LD	HL,FF_UNKNOWN		; WE REACHED THE END WITHOUT A MATCH
 ;
 FF_NXT2:CALL	PRTSTR			; AFTER SEARCH DISPLAY THE RESULT
+	RET
+;
+;======================================================================
+; IDENTIFY FLASH CHIP. 
+;  CALCULATE BANK AND ADDRESS DATA FROM ENTRY ADDRESS
+;  CREATE A CODE BUFFER IN THE STACK AREA
+;  COPY FLASH CODE TO CODE BUFFER
+;  CALL RELOCATED FLASH IDENTITY CODE
+;  RESTORE STACK
+;  RETURN WITH ID CODE.
+;
+; ON ENTRY DE:HL POINTS TO AN ADDRESS WITH THE ADDRESS RANGE OF THE
+;                CHIP TO BE IDENTIFIED.
+; ON EXIT  DE CONTAINS THE CHIP ID BYTES.
+;          NO STATUS IS RETURNED               
+;======================================================================
+;
+FF_IINIT:
+	CALL	FF_CALCA		; GET BANK AND SECTOR DATA IN IY
+;
+	LD	(FF_STACK),SP		; SAVE STACK
+	LD	HL,(FF_STACK)
+;
+	LD	BC,FF_I_SZ		; CODE SIZE REQUIRED
+	CCF				; CREATE A RELOCATABLE
+	SBC	HL,BC			; CODE BUFFER IN THE
+	LD	SP,HL			; STACK AREA
+;
+	PUSH	HL			; SAVE THE EXECUTE ADDRESS
+	EX	DE,HL			; PUT EXECUTE / START ADDRESS IN DE
+	LD	HL,FF_IDENT		; COPY OUR RELOCATABLE
+	LDIR				; CODE TO THE BUFFER
+	POP	HL			; CALL OUR RELOCATABLE CODE
+
+	PUSH	IY			; PUT BANK AND SECTOR
+	POP	BC			; DATA IN BC
+;
+	LD	A,(HB_CURBNK)		; WE ARE STARTING IN HB_CURBNK
+;
+	CALL	JPHL			; EXECUTE FF_IDENT
+;
+	LD	HL,(FF_STACK)		; RESTORE ORIGINAL 
+	LD	SP,HL			; STACK POSITION
 ;
-	XOR	A			; INIT SUCCEEDED
 	RET
 ;
 ;======================================================================
-; IDENTIFY FLASH CHIP. THIS CODE IS RELOCATED AND EXECUTED IN THE STACK.
-; IT SWITCHES THE BOTTOM BANK TO ROM BANK 0 I.E. BOTTOM OF CHIP ADDRESS RANGE.
-; RETURNS WITH CHIP ID IN DE AND RETURNS THE BOTTOM BANK TO INITIAL STATE.
+; FLASH IDENTIFY
+;  SELECT THE APPROPRIATE BANK / ADDRESS
+;  ISSUE ID COMMAND
+;  READ IN ID WORD
+;  ISSUE ID EXIT COMMAND
+;  SELECT ORIGINAL BANK
+;
+; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
+;          A  CONTAINS CURRENT BANK 
+; ON EXIT  DE CONTAINS ID WORD
+;          NO STATUS IS RETURNED 
 ;======================================================================
 ;
-FF_IDENT:				; FLASH ROM ID CODE			``
+FF_IDENT:				; THIS CODE GETS RELOCATED TO THE STACK
 	HB_DI
-	CALL	HBX_BNKSEL		; SELECT ROM BANK 0
 ;
-	LD	A,$AA			; SET IDENTIFY MODE
-	LD	($5555),A
+	PUSH	AF			; SAVE CURRENT BANK
+	LD	A,B			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO PROGRAM
+;
+	LD	HL,$5555		; LD	A,$AA			; COMMAND
+	LD	(HL),$AA		; LD	($5555),A		; SETUP
+	LD	A,H			; LD	A,$55
+	LD	($2AAA),A		; LD	($2AAA),A
+	LD	(HL),$90		; LD	A,$90
+;					; LD	($5555),A
+	LD	DE,($0000)						; READ ID
+;
+	LD	A,$F0			; 				; EXIT 
+	LD	(HL),A			; LD	($5555),A		; COMMAND
+;
+	POP	AF			; RETURN TO ORIGINAL BANK
+	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
+	HB_EI
+;
+	RET
+;
+FF_I_SZ	.EQU	$-FF_IDENT		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
+;
+;======================================================================
+; FLASH CHIP ERASE.
+;  CALCULATE BANK AND ADDRESS DATA FROM ENTRY ADDRESS
+;  CREATE A CODE BUFFER IN THE STACK AREA
+;  COPY FLASH CODE TO CODE BUFFER
+;  CALL RELOCATED FLASH ERASE CODE
+;  RESTORE STACK
+;  RETURN WITH STATUS CODE.
+;
+; ON ENTRY DE:HL POINTS TO AN ADDRESS IDENTIFYING THE CHIP
+; ON EXIT  A     RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+;======================================================================
+;
+FF_EINIT:
+	CALL	FF_CALCA		; GET BANK AND SECTOR DATA IN IY
+
+	LD	(FF_STACK),SP		; SAVE STACK
+	LD	HL,(FF_STACK)
+;
+	LD	BC,FF_E_SZ		; CODE SIZE REQUIRED
+	CCF				; CREATE A RELOCATABLE
+	SBC	HL,BC			; CODE BUFFER IN THE
+	LD	SP,HL			; STACK AREA
+;
+	PUSH	HL			; SAVE THE EXECUTE ADDRESS
+	EX	DE,HL			; PUT EXECUTE / START ADDRESS IN DE
+	LD	HL,FF_ERASE		; COPY OUR RELOCATABLE
+	LDIR				; CODE TO THE BUFFER
+	POP	HL			; CALL OUR RELOCATABLE CODE
+;
+	PUSH	IY			; PUT BANK AND SECTOR
+	POP	BC			; DATA IN BC
+;
+	LD	A,(HB_CURBNK)		; WE ARE STARTING IN HB_CURBNK
+;
+	CALL	JPHL			; EXECUTE FF_ERASE
+;
+	LD	HL,(FF_STACK)		; RESTORE ORIGINAL 
+	LD	SP,HL			; STACK POSITION
+;
+	LD	A,C			; RETURN WITH STATUS IN A
+	RET
+;
+;======================================================================
+; ERASE FLASH CHIP. 
+;
+;  SELECT THE APPROPRIATE BANK / ADDRESS
+;  ISSUE ERASE COMMAND
+;  POLL TOGGLE BIT FOR COMPLETION STATUS.
+;  SELECT ORIGINAL BANK
+;
+; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
+;          A  CONTAINS CURRENT BANK 
+; ON EXIT  DE CONTAINS ID WORD
+;          A  RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+;======================================================================
+;
+FF_ERASE:				; THIS CODE GETS RELOCATED TO THE STACK
+	HB_DI
+;
+	PUSH	AF			; SAVE CURRENT BANK
+	LD	A,B			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO PROGRAM
+;
+	LD	HL,$5555
+	LD	A,$AA			; LD	A,$AA		; COMMAND
+	LD	(HL),A			; LD	($5555),A	; SETUP
+	LD	A,L			; LD	A,$55
+	LD	($2AAA),A		; LD	($2AAA),A
+	LD	A,$80			; LD	A,$80
+	LD	(HL),A			; LD	($5555),A
+	LD	A,$AA			; LD	A,$AA
+	LD	(HL),A			; LD	($5555),A
+	LD	A,L			; LD	A,$55
+	LD	($2AAA),A		; LD	($2AAA),A
+	LD	A,$10			; LD	A,$10
+	LD	(HL),A			; LD	($5555),A
+;
+	LD	A,(HL)			; DO TWO SUCCESSIVE READS FROM THE SAME FLASH ADDRESS. 
+FF_WT2:	LD	C,(HL)			; IF TOGGLE BIT (BIT 6) 
+	XOR	C			; IS THE SAME ON BOTH READS
+	BIT	6,A			; THEN ERASE IS COMPLETE SO EXIT.
+	JR	Z,FF_WT1		; Z TRUE IF BIT 6=0 I.E. "NO TOGGLE" WAS DETECTED. 
+;
+	LD	A,C			; OPERATION IS NOT COMPLETE. CHECK TIMEOUT BIT (BIT 5).
+	BIT	5,C			; IF NO TIMEOUT YET THEN LOOP BACK AND KEEP CHECKING TOGGLE STATUS
+	JR	Z,FF_WT2		; IF BIT 5=0 THEN RETRY; NZ TRUE IF BIT 5=1
+;
+	LD	A,(HL)			; WE GOT A TIMEOUT. RECHECK TOGGLE BIT IN CASE WE DID COMPLETE 
+	XOR	(HL)			; THE OPERATION. DO TWO SUCCESSIVE READS. ARE THEY THE SAME?
+	BIT	6,A			; IF THEY ARE THEN OPERATION WAS COMPLETED					
+	JR	Z,FF_WT1		; OTHERWISE ERASE OPERATION FAILED OR TIMED OUT.
+;
+	LD	(HL),$F0		; WRITE DEVICE RESET
+	LD	C,$FF			; SET FAIL STATUS
+	JR	FF_WT3
+;
+FF_WT1:	LD	C,0			; SET SUCCESS STATUS
+FF_WT3:	POP	AF
+;	LD	A,B			; RETURN TO ORIGINAL BANK
+	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
+	HB_EI
+;
+	RET
+;
+FF_E_SZ	.EQU	$-FF_ERASE		; 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
+;
+; DDDDDDDDEEEEEEEE HHHHHHHHLLLLLLLL
+; 3322222222221111 1111110000000000
+; 1098765432109876 5432109876543210
+; XXXXXXXXXXXXSSSS SSSSXXXXXXXXXXXX < S = SECTOR
+; XXXXXXXXXXXXBBBB BXXXXXXXXXXXXXXX < B = BANK
+;======================================================================
+;
+FF_CALCA:
+;
+#IF (FF_DBG==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 (FF_DBG==1)
+	CALL	PRTHEXWORD	; DISPLAY BANK AND
+	CALL	PC_SPACE	; SECTOR RESULT
+#ENDIF
+;
+	RET
+;
+;======================================================================
+; ERASE FLASH SECTOR
+;
+; ON ENTRY DE:HL CONTAINS 32 BIT MEMORY ADDRESS.
+;  CALCULATE BANK AND ADDRESS DATA FROM ENTRY ADDRESS
+;  CREATE A CODE BUFFER IN THE STACK AREA
+;  COPY FLASH CODE TO CODE BUFFER
+;  CALL RELOCATED FLASH ERASE CODE
+;  RESTORE STACK
+;  RETURN WITH STATUS CODE.
+;
+; ON ENTRY DE:HL POINTS TO AN ADDRESS IDENTIFYING THE CHIP
+; ON EXIT  A     RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+;======================================================================
+;
+FF_SINIT:
+	CALL	FF_CALCA		; GET BANK AND SECTOR DATA IN IY
+;
+	LD	(FF_STACK),SP		; SAVE STACK
+	LD	HL,(FF_STACK)
+;
+	LD	BC,FF_S_SZ		; CODE SIZE REQUIRED
+	CCF				; CREATE A RELOCATABLE
+	SBC	HL,BC			; CODE BUFFER IN THE
+	LD	SP,HL			; STACK AREA
+;
+	PUSH	HL			; SAVE THE EXECUTE ADDRESS
+	EX	DE,HL			; PUT EXECUTE / START ADDRESS IN DE
+	LD	HL,FF_SERASE		; COPY OUR RELOCATABLE
+	LDIR				; CODE TO THE BUFFER
+	POP	HL			; CALL OUR RELOCATABLE CODE
+;
+	PUSH	IY			; PUT BANK AND SECTOR
+	POP	BC			; DATA IN BC
+;
+#IF (FF_DBG==1)
+	CALL	PRTHEXWORD
+#ENDIF
+;
+	LD	A,(HB_CURBNK)		; WE ARE STARTING IN HB_CURBNK	
+;
+	CALL	JPHL			; CALL FF_SERASE
+;
+	LD	HL,(FF_STACK)		; RESTORE ORIGINAL 
+	LD	SP,HL			; STACK POSITION
+;
+#IF (FF_DBG==1)
+	CALL	PRTHEXWORD
+	CALL	PC_SPACE
+	EX	DE,HL
+	CALL	PRTHEXWORDHL
+	CALL	PC_SPACE
+#ENDIF
+;
+	LD	A,C			; STATUS
+	RET
+;
+;======================================================================
+; ERASE FLASH SECTOR. 
+;
+;  SELECT THE APPROPRIATE BANK / ADDRESS
+;  ISSUE ERASE SECTOR COMMAND
+;  POLL TOGGLE BIT FOR COMPLETION STATUS.
+;  SELECT ORIGINAL BANK
+;
+; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
+;          A  CONTAINS CURRENT BANK 
+; ON EXIT  A  RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+;======================================================================
+;
+FF_SERASE:				; THIS CODE GETS RELOCATED TO THE STACK
+	HB_DI
+;
+	PUSH	AF			; SAVE CURRENT BANK
+	LD	A,B			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO PROGRAM
+;
+	LD	A,$AA			; COMMAND
+	LD	($5555),A		; SETUP
 	LD	A,$55
 	LD	($2AAA),A
-;
-	LD	A,$90
+	LD	A,$80
 	LD	($5555),A
+	LD	A,$AA
+	LD	($5555),A
+	LD	A,$55
+	LD	($2AAA),A
+
+	LD	H,C			; SECTOR 
+	LD	L,$00			; ADDRESS
 ;
-	LD	DE,($0000)
+	LD	A,$30			; SECTOR ERASE
+	LD	(HL),A			; COMMAND
 ;
-	LD	A,$F0			; EXIT IDENTIFY MODE
-	LD	($5555),A
+	LD	DE,$0000		; DEBUG COUNT
 ;
-	LD	A,B			; RETURN TO ORIGINAL BANK
+	LD	A,(HL)			; DO TWO SUCCESSIVE READS
+FF_WT4:	LD	C,(HL)			; FROM THE SAME FLASH ADDRESS.
+	XOR	C			; IF THE SAME ON BOTH READS
+	BIT	6,A			; THEN ERASE IS COMPLETE SO EXIT.
+	INC	DE			; 
+	JR	Z,FF_WT5		; BIT 6 = 0 IF SAME ON SUCCESSIVE READS = COMPLETE
+					; BIT 6 = 1 IF DIFF ON SUCCESSIVE READS = INCOMPLETE
+;
+	LD	A,C			; OPERATION IS NOT COMPLETE. CHECK TIMEOUT BIT (BIT 5).
+	BIT	5,C			; IF NO TIMEOUT YET THEN LOOP BACK AND KEEP CHECKING TOGGLE STATUS
+	JR	Z,FF_WT4		; IF BIT 5=0 THEN RETRY; NZ TRUE IF BIT 5=1
+;
+	LD	A,(HL)			; WE GOT A TIMOUT. RECHECK TOGGLE BIT IN CASE WE DID COMPLETE 
+	XOR	(HL)			; THE OPERATION. DO TWO SUCCESSIVE READS. ARE THEY THE SAME?
+	BIT	6,A			; IF THEY ARE THEN OPERATION WAS COMPLETED					
+	JR	Z,FF_WT5		; OTHERWISE ERASE OPERATION FAILED OR TIMED OUT.
+;
+	LD	(HL),$F0		; WRITE DEVICE RESET
+	LD	C,$FF			; SET FAIL STATUS
+	JR	FF_WT6
+;
+FF_WT5:	LD	C,0			; SET SUCCESS STATUS
+FF_WT6:	POP	AF			; RETURN TO ORIGINAL BANK
 	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
 	HB_EI
 ;
 	RET
 ;
-FF_I_SZ	.EQU	$-FF_IDENT
+FF_S_SZ	.EQU	$-FF_SERASE		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
+;
+;======================================================================
+; WRITE FLASH SECTOR OF 4096 BYTES
+;
+; SET ADDRESS TO START OF SECTOR
+; CALCULATE BANK AND ADDRESS DATA FROM SECTOR START ADDRESS
+;  CREATE A CODE BUFFER IN THE STACK AREA
+;  COPY FLASH CODE TO CODE BUFFER
+;  CALL RELOCATED FLASH WRITE SECTOR CODE
+;  RESTORE STACK
+;
+; ON ENTRY DE:HL POINTS TO A 32 BIT MEMORY ADDRESS.
+;          IX    POINTS TO DATA TO BE WRITTEN
+;======================================================================
+;
+FF_WINIT:
+	LD	L,0			; CHANGE ADDRESS
+	LD	A,H			; TO SECTOR BOUNDARY
+	AND	$F0			; BY MASKING OFF
+	LD	H,A			; LOWER 12 BITS
+;
+	CALL	FF_CALCA		; GET BANK AND SECTOR DATA IN IY
+;
+	LD	(FF_STACK),SP		; SAVE STACK
+	LD	HL,(FF_STACK)
+;
+	LD	BC,FF_W_SZ		; CODE SIZE REQUIRED
+	CCF				; CREATE A RELOCATABLE
+	SBC	HL,BC			; CODE BUFFER IN THE
+	LD	SP,HL			; STACK AREA
+;
+	PUSH	HL			; SAVE THE EXECUTE ADDRESS
+	EX	DE,HL			; PUT EXECUTE / START ADDRESS IN DE
+	LD	HL,FF_SWRITE		; COPY OUR RELOCATABLE
+	LDIR				; CODE TO THE BUFFER
+	POP	HL			; CALL OUR RELOCATABLE CODE
+;
+	PUSH	IY			; PUT BANK AND SECTOR
+	POP	BC			; DATA IN BC
+;
+	LD	A,(HB_CURBNK)		; WE ARE STARTING IN HB_CURBNK	
+;
+	CALL	JPHL			; CALL FF_SWRITE
+;
+	LD	HL,(FF_STACK)		; RESTORE ORIGINAL 
+	LD	SP,HL			; STACK POSITION
+;
+#IF (FF_DBG==1)
+	CALL	PC_SPACE
+	EX	DE,HL
+	CALL	PRTHEXWORDHL
+	CALL	PC_SPACE
+#ENDIF
+;
+	XOR	A			; STATUS
+	RET
+;
+;======================================================================
+; FLASH WRITE SECTOR. 
+;
+;  SELECT THE APPROPRIATE BANK / ADDRESS
+;  WRITE 1 SECTOR OF 4096 BYTES, BYTE AT A TIME
+;   ISSUE WRITE BYTE COMMAND AND WRITE THE DATA BYTE
+;   POLL TOGGLE BIT FOR COMPLETION STATUS.
+;  SELECT ORIGINAL BANK
+;
+; ON ENTRY BC CONTAINS BANK AND SECTOR DATA
+;          IX POINTS TO DATA TO BE WRITTEN
+;          A  CONTAINS CURRENT BANK 
+; ON EXIT  A  RETURNS STATUS FLASH 0=SUCCESS FF=FAIL
+;======================================================================
+;
+FF_SWRITE:				; THIS CODE GETS RELOCATED TO THE STACK
+	HB_DI
+;
+	LD	DE,$0000		; INITIALIZE BYTE COUNT
+;
+	LD	H,C			; SECTOR
+	LD	L,$00			; ADDRESS
+;
+	PUSH	AF			; SAVE CURRENT BANK
+	LD	A,B			; SELECT BANK
+	CALL	HBX_BNKSEL		; TO PROGRAM
+;
+FF_WR1:
+	LD	B,(IX+0)		; READ IN BYTE
+;
+	LD	A,$AA			; COMMAND
+	LD	($5555),A		; SETUP
+	LD	A,$55
+	LD	($2AAA),A
+;
+	LD	A,$A0			; WRITE
+	LD	($5555),A		; COMMAND
+;
+	LD	(HL),B			; WRITE OUT BYTE
+;
+;					; DO TWO SUCCESSIVE READS 
+	LD	A,(HL)			; FROM THE SAME FLASH ADDRESS. 
+FF_WT7:	LD	C,(HL)			; IF TOGGLE BIT (BIT 6) 
+	XOR	C			; IS THE SAME ON BOTH READS
+	BIT	6,A			; THEN ERASE IS COMPLETE SO EXIT.
+	JR	NZ,FF_WT7		; Z TRUE IF BIT 6=0 I.E. "NO TOGGLE" WAS DETECTED. 
+
+	INC	HL			; NEXT DESTINATION LOCATION
+	INC	IX			; NEXT SOURCE LOCATION
+
+	INC	DE			; CONTINUE WRITING UNTIL
+	BIT	4,D			; WE HAVE DONE ONE SECTOR
+	JR	Z,FF_WR1
+
+	POP	AF			; RETURN TO ORIGINAL BANK
+	CALL	HBX_BNKSEL		; WHICH IS OUR RAM BIOS COPY
+	HB_EI
+;
+	RET
+;
+FF_W_SZ	.EQU	$-FF_SWRITE		; SIZE OF RELOCATABLE CODE BUFFER REQUIRED
+;
+;======================================================================
 ;
 ;	FLASH STYLE
 ;
+;======================================================================
+;
 ST_NORMAL	.EQU	0
-ST_ERASE_CHIP	.EQU	1
+ST_ERASE_CHIP	.EQU	1		; SECTOR BASED ERASE NOT SUPPORTED
 ST_PROGRAM_SECT	.EQU	2
 ;
+;======================================================================
+;
 ; FLASH CHIP MACRO
 ;
-#DEFINE	FF_CHIP(FFROMID,FFROMNM,FFROMSS,FFROMMD) 	\
+;======================================================================
+;
+#DEFINE	FF_CHIP(FFROMID,FFROMNM,FFROMSS,FFROMSC,FFROMMD)\
 #DEFCONT ;						\
 #DEFCONT	.DW	FFROMID				\
 #DEFCONT	.DB	FFROMNM				\
 #DEFCONT	.DW	FFROMSS				\
-#DEFCONT	.DW	FFROMMD				\
+#DEFCONT	.DW	FFROMSC				\
+#DEFCONT	.DB	FFROMMD				\
 #DEFCONT ;
 ;
+;======================================================================
+;
 ; FLASH CHIP LIST
 ;
+;======================================================================
+;
 FF_TABLE:
-FF_CHIP(00120H,"29F010$    ",128,ST_NORMAL)
-FF_CHIP(001A4H,"29F040$    ",512,ST_NORMAL)
-FF_CHIP(01F04H,"AT49F001NT$",1024,ST_ERASE_CHIP)
-FF_CHIP(01F05H,"AT49F001N$ ",1024,ST_ERASE_CHIP)
-FF_CHIP(01F07H,"AT49F002N$ ",2048,ST_ERASE_CHIP)
-FF_CHIP(01F08H,"AT49F002NT$",2048,ST_ERASE_CHIP)
-FF_CHIP(01F13H,"AT49F040$  ",4096,ST_ERASE_CHIP)
-FF_CHIP(01F5DH,"AT29C512$  ",1,ST_PROGRAM_SECT)
-FF_CHIP(01FA4H,"AT29C040$  ",2,ST_PROGRAM_SECT)
-FF_CHIP(01FD5H,"AT29C010$  ",1,ST_PROGRAM_SECT)
-FF_CHIP(01FDAH,"AT29C020$  ",2,ST_PROGRAM_SECT)
-FF_CHIP(02020H,"M29F010$   ",128,ST_PROGRAM_SECT)
-FF_CHIP(020E2H,"M29F040$   ",512,ST_NORMAL)
-FF_CHIP(0BFB5H,"39F010$    ",32,ST_NORMAL)
-FF_CHIP(0BFB6H,"39F020$    ",32,ST_NORMAL)
-FF_CHIP(0BFB7H,"39F040$    ",32,ST_NORMAL)
-FF_CHIP(0C2A4H,"MX29F040$  ",512,ST_NORMAL)
-;
-FF_T_CNT	.EQU	($-FF_TABLE) / 17
+FF_CHIP(00120H,"29F010$    ",128,8,ST_NORMAL)
+FF_CHIP(001A4H,"29F040$    ",512,8,ST_NORMAL)
+FF_CHIP(01F04H,"AT49F001NT$",1024,1,ST_ERASE_CHIP)
+FF_CHIP(01F05H,"AT49F001N$ ",1024,1,ST_ERASE_CHIP)
+FF_CHIP(01F07H,"AT49F002N$ ",2048,1,ST_ERASE_CHIP)
+FF_CHIP(01F08H,"AT49F002NT$",2048,1,ST_ERASE_CHIP)
+FF_CHIP(01F13H,"AT49F040$  ",4096,1,ST_ERASE_CHIP)
+FF_CHIP(01F5DH,"AT29C512$  ",1,512,ST_PROGRAM_SECT)
+FF_CHIP(01FA4H,"AT29C040$  ",2,2048,ST_PROGRAM_SECT)
+FF_CHIP(01FD5H,"AT29C010$  ",1,1024,ST_PROGRAM_SECT)
+FF_CHIP(01FDAH,"AT29C020$  ",2,1024,ST_PROGRAM_SECT)
+FF_CHIP(02020H,"M29F010$   ",128,8,ST_PROGRAM_SECT)
+FF_CHIP(020E2H,"M29F040$   ",512,8,ST_NORMAL)
+FF_CHIP(0BFB5H,"39F010$    ",32,32,ST_NORMAL)
+FF_CHIP(0BFB6H,"39F020$    ",32,64,ST_NORMAL)
+FF_CHIP(0BFB7H,"39F040$    ",32,128,ST_NORMAL)
+FF_CHIP(0C2A4H,"MX29F040$  ",512,8,ST_NORMAL)
+;
+FF_T_CNT	.EQU	17
+FF_T_SZ		.EQU	($-FF_TABLE) / FF_T_CNT
 FF_UNKNOWN	.DB	"UNKNOWN$"
 FF_STACK:	.DW	0
+;
+;======================================================================
+;
+; RELOCATABLE CODE SPACE REQUIREMENTS
+;
+;======================================================================
+;
+FF_CSIZE	.EQU	0
+;
+#IF (FF_W_SZ>FF_CSIZE)
+FF_CSIZE	.SET	FF_W_SZ
+#ENDIF
+#IF (FF_S_SZ>FF_CSIZE)
+FF_CSIZE	.SET	FF_S_SZ
+#ENDIF
+#IF (FF_E_SZ>FF_CSIZE)
+FF_CSIZE	.SET	FF_E_SZ
+#ENDIF
+#IF (FF_I_SZ>FF_CSIZE)
+FF_CSIZE	.SET	FF_I_SZ
+#ENDIF
+;
+		.ECHO	"FF requires "
+		.ECHO	FF_CSIZE
+		.ECHO	" bytes stack space.\n"