diff --git a/Source/Apps/Assign.asm b/Source/Apps/Assign.asm
index e76adab7..28a950ba 100644
--- a/Source/Apps/Assign.asm
+++ b/Source/Apps/Assign.asm
@@ -27,7 +27,6 @@
 ; ToDo:
 ;  1) Do something to prevent assigning slices when device does not support them
 ;  2) ASSIGN C: causes drive map to be reinstalled unnecessarily
-;  3) Need to find a way to verify RomWBW under CP/M 3
 ;_______________________________________________________________________________
 ;
 ;===============================================================================
@@ -106,7 +105,6 @@ init:
 	ld	(cpmver),hl	; save it
 	ld	a,l		; low byte
 	cp	$30		; CP/M 3.0?
-	jp	nc,initcpm3	; handle CP/M 3.0 or greater
 ;
 	; get location of config data and verify integrity
 	ld	hl,stamp	; HL := adr or RomWBW zero page stamp
@@ -146,6 +144,11 @@ init:
 	inc	hl		; ... into DE to get
 	ld	d,(hl)		; ... DPB map pointer
 	ld	(dpbloc),de	; and save it	
+;
+	; test for CP/M 3 and branch if so
+	ld	a,(cpmver)	; low byte of cpm version
+	cp	$30		; CP/M 3.0?
+	jp	nc,initcpm3	; handle CP/M 3.0 or greater
 ;
 	; make a local working copy of the drive map
 	ld	hl,(maploc)	; copy from CBIOS drive map
diff --git a/Source/CBIOS/cbios.asm b/Source/CBIOS/cbios.asm
index a1b5320e..971d3690 100644
--- a/Source/CBIOS/cbios.asm
+++ b/Source/CBIOS/cbios.asm
@@ -131,7 +131,7 @@ STPSIZ	.EQU	$ - STPIMG
 ;
 ; The following section contains key information and addresses for the
 ; RomWBW CBIOS.  A pointer to the start of this section is stored with
-; with the ZPX data in page zero at $44 (see above).
+; with the CBX data in page zero at $44 (see above).
 ;
 CBX:
 DEVMAPADR	.DW	DEVMAP		; DEVICE MAP ADDRESS
diff --git a/Source/CPM3/boot.z80 b/Source/CPM3/boot.z80
index 0e8b1013..a870edea 100644
--- a/Source/CPM3/boot.z80
+++ b/Source/CPM3/boot.z80
@@ -12,6 +12,8 @@
 	extrn	dph0
 	extrn	@dtbl,@ctbl
 	
+	include	ver.inc
+	
 bdos	equ 5
 
 	if banked
@@ -25,14 +27,11 @@ tpa$bank	equ 0
 ?init:
 	call	?mvinit
 
-	; Clear reserved area in page zero
-	xor	a
-	ld	hl,40h
-	ld	b,10h
-init$1:
-	ld	(hl),a
-	inc	hl
-	djnz	init$1
+	; Install RomWBW CBIOS stamp in page zero
+	ld	hl,stpimg
+	ld	de,stploc
+	ld	bc,stpsiz
+	ldir
 
 	if banked
 
@@ -382,12 +381,13 @@ read:
 	ld	c,20
 	jp	bdos
 
-
 signon$msg	db	13,10,'CP/M v3.0'
 	if banked
 		db	' [BANKED]'
 	endif
-		db	' for RomWBW HBIOS v2.9.2',13,10,13,10,0
+		db	' on HBIOS v'
+		biosver
+		db	13,10,13,10,0
 
 ccp$msg		db	13,10,'BIOS Err on '
 ccp$msg$drv	db	'?'
@@ -401,4 +401,27 @@ fcb$nr		db	0,0,0
 @bootdu		db	0
 hdspv		db	2		; slices per volume for hard disks (must be >= 1)
 
+; RomWBW CBIOS page zero stamp starts at $40
+; $40-$41: Marker ('W', ~'W')
+; $42-$43: Version bytes: major/minor, update/patch
+; $44-$45: CBIOS Extension Info address
+;
+stploc	equ	40h
+stpimg	db	'W',~'W'		; marker
+	db	rmj << 4 | rmn		; first byte of version info
+	db	rup << 4 | rtp		; second byte of version info
+	dw	cbx			; address of cbios ext data
+stpsiz	equ	$ - stpimg
+
+;
+; The following section contains key information and addresses for the
+; RomWBW CBIOS.  A pointer to the start of this section is stored with
+; with the CBX data in page zero at $44 (see above).
+;
+cbx:
+devmapadr	dw	0		; device map address
+drvtbladr	dw	@dtbl		; drive map address (filled in later)
+dphtbladr	dw	dph0		; dpb map address
+cbxsiz		equ	$ - cbx
+;
 	end
diff --git a/Source/CPM3/ver.inc b/Source/CPM3/ver.inc
new file mode 100644
index 00000000..379d1cd7
--- /dev/null
+++ b/Source/CPM3/ver.inc
@@ -0,0 +1,7 @@
+rmj	equ	2
+rmn	equ	9
+rup	equ	2
+rtp	equ	0
+biosver	macro
+	db	"2.9.2-pre.21"
+	endm