diff --git a/Source/HBIOS/ansi.asm b/Source/HBIOS/ansi.asm
index 720926d1..bde6b869 100644
--- a/Source/HBIOS/ansi.asm
+++ b/Source/HBIOS/ansi.asm
@@ -27,8 +27,8 @@ ANSI_DEFCOLOR	.EQU	7	; WHITE ON BLACK
 ;
 ANSI_INIT:
 	; SAVE INCOMING VDA DISPATCH ADDRESS
-	LD	C,A			; VDA DRIVER'S DEVICE TYPE
-	LD	(ANSI_DEVTYPE),A		; ... SAVED LOCALLY
+	LD	A,C			; VDA DRIVER'S DEVICE TYPE
+	LD	(ANSI_DEVTYPE),A	; ... SAVED LOCALLY
 	LD	(ANSI_VDADISPADR),DE	; RECORD NEW VDA DISPATCH ADDRESS
 	CALL	ANSI_RESET		; FULL RESET OF EMULATOR INTERNAL STATE
 	LD	DE,ANSI_DISPATCH	; RETURN OUR DISPATCH ADDRESS
diff --git a/Source/HBIOS/cvdu.asm b/Source/HBIOS/cvdu.asm
index 82a0fd1b..084fbe5d 100644
--- a/Source/HBIOS/cvdu.asm
+++ b/Source/HBIOS/cvdu.asm
@@ -37,12 +37,17 @@ CVDU_INIT:
 	PRTS("KB$")
 	CALL	CVDU_LOADFONT		; LOAD FONT DATA FROM ROM TO CVDU STRORAGE
 
+	; ADD OURSELVES TO VDA DISPATCH TABLE
+	LD	B,0			; PHYSICAL UNIT IS ZERO
+	LD	C,VDADEV_CVDU		; DEVICE TYPE
+	LD	DE,0			; UNIT DATA BLOB ADDRESS
+	CALL	VDA_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
+	
 	; ADD OURSELVES TO CIO DISPATCH TABLE
 	LD	B,0			; PHYSICAL UNIT IS ZERO
 	LD	C,CIODEV_CVDU		; DEVICE TYPE
 	LD	DE,0			; UNIT DATA BLOB ADDRESS
 	CALL	CIO_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
-	;LD	(CVDU_CIOUNIT),A	; SAVE IT LOCALLY
 	LD	(HCB + HCB_CRTDEV),A	; SET OURSELVES AS THE CRT DEVICE
 	
 	LD	D,VDAEMU		; DEFAULT EMULATION
@@ -71,27 +76,29 @@ CVDU_DISPATCH:
 	DEC	A
 	JP	Z,CVDU_VDARES	; $42
 	DEC	A
-	JP	Z,CVDU_VDASCS	; $43
+	JP	Z,CVDU_VDADEV	; $43
 	DEC	A
-	JP	Z,CVDU_VDASCP	; $44
+	JP	Z,CVDU_VDASCS	; $44
 	DEC	A
-	JP	Z,CVDU_VDASAT	; $45
+	JP	Z,CVDU_VDASCP	; $45
 	DEC	A
-	JP	Z,CVDU_VDASCO	; $46
+	JP	Z,CVDU_VDASAT	; $46
 	DEC	A
-	JP	Z,CVDU_VDAWRC	; $47
+	JP	Z,CVDU_VDASCO	; $47
 	DEC	A
-	JP	Z,CVDU_VDAFIL	; $48
+	JP	Z,CVDU_VDAWRC	; $48
 	DEC	A
-	JP	Z,CVDU_VDACPY	; $49
+	JP	Z,CVDU_VDAFIL	; $49
 	DEC	A
-	JP	Z,CVDU_VDASCR	; $4A
+	JP	Z,CVDU_VDACPY	; $4A
 	DEC	A
-	JP	Z,KBD_STAT	; $4B
+	JP	Z,CVDU_VDASCR	; $4B
 	DEC	A
-	JP	Z,KBD_FLUSH	; $4C
+	JP	Z,KBD_STAT	; $4C
 	DEC	A
-	JP	Z,KBD_READ	; $4D
+	JP	Z,KBD_FLUSH	; $4D
+	DEC	A
+	JP	Z,KBD_READ	; $4E
 	CALL	PANIC
 
 CVDU_VDAINI:
@@ -102,8 +109,6 @@ CVDU_VDAINI:
 
 	; INITIALIZE EMULATION
 	LD	B,D			; EMULATION TYPE TO B
-	;LD	A,(CVDU_CIOUNIT)	; CIO UNIT NUMBER
-	;LD	C,A			; ... IS PASSED IN C
 	LD	C,CIODEV_CVDU		; PASS OUR DEVICE TYPE IN C
 	LD	DE,CVDU_DISPATCH	; DISPATCH ADDRESS TO DE
 	CALL	EMU_INIT		; INITIALIZE EMULATION, DE := CIO DISPATCHER
@@ -134,7 +139,12 @@ CVDU_VDARES:
 	
 	XOR	A
 	RET
-	
+
+CVDU_VDADEV:
+	LD	D,VDADEV_CVDU	; D := DEVICE TYPE
+	LD	E,C		; E := PHYSICAL UNIT
+	XOR	A		; SIGNAL SUCCESS
+	RET
 	
 CVDU_VDASCS:
 	CALL	PANIC		; NOT IMPLEMENTED (YET)
@@ -650,8 +660,6 @@ CVDU_BLKCPY1:
 ;   CVDU DRIVER - DATA
 ;==================================================================================================
 ;
-;CVDU_CIOUNIT		.DB	$FF	; LOCAL COPY OF OUR CIO UNIT NUMBER
-;
 CVDU_ATTR		.DB	0	; CURRENT COLOR
 CVDU_POS		.DW 	0	; CURRENT DISPLAY POSITION
 ;
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index daeca3e1..3aef7262 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -1105,8 +1105,39 @@ EMU_INIT1:
 ;   C: UNIT NUMBER
 ;
 VDA_DISPATCH:
-	LD	A,C		; REQUESTED DEVICE/UNIT IS IN C
-	AND	$F0		; ISOLATE THE DEVICE PORTION
+;	LD	A,C		; REQUESTED DEVICE/UNIT IS IN C
+;	AND	$F0		; ISOLATE THE DEVICE PORTION
+
+;
+; ON ENTRY C IS HBIOS UNIT # (INDEX INTO VDA_TBL OF VIDEO DEVICES)
+; USE UNIT # IN C TO LOOKUP VDA_TBL ENTRY, THEN
+; CONVERT C TO THE DEVICE/DRIVER SPECIFIC UNIT ID
+; AND GET THE DEVICE TYPE TO A FOR DRIVER DISPATCHING
+;
+	LD	A,C			; INCOMING UNIT INDEX TO A
+	PUSH	HL			; SAVE INCOMING HL
+	LD	HL,VDA_CNT		; HL := ADDRESS OF TABLE ENTRY COUNT
+	CP	(HL)			; COMPARE TO INCOMING ENTRY INDEX
+	JR	C,VDA_DISPATCH1		; UNIT OK, PROCEED
+;	
+	; NOT GOOD, INCOMING UNIT IS OUT OF RANGE
+	POP	HL			; RESTORE HL/STACK
+	CALL	PANIC			; PANIC
+	OR	$FF			; SIGNAL ERROR
+	RET				; AND RETURN
+;
+VDA_DISPATCH1:
+	INC	HL			; BUMP PAST COUNT PREFIX TO START OF TABLE
+	RLCA				; MULTIPLY BY 4 TO
+	RLCA				; ... TO CALC ENTRY OFFSET
+	CALL	ADDHLA			; HL := ENTRY OFFSET
+	LD	A,(HL)			; GET DEVICE TYPE BYTE
+	INC	HL			; BUMP TO DEVICE UNIT INDEX BYTE
+	LD	C,(HL)			; DEVICE UNIT INDEX TO C
+	POP	HL			; RECOVER INCOMING HL VALUE
+;
+; DISPATCH TO DRIVER BASED ON DEVICE TYPE IN A
+;
 #IF (VDUENABLE)
 	CP	VDADEV_VDU
 	JP	Z,VDU_DISPATCH
@@ -1125,6 +1156,30 @@ VDA_DISPATCH:
 #ENDIF
 	CALL	PANIC
 ;
+; HBIOS VIDEO DEVICE UNIT TABLE
+;
+; TABLE IS BUILT DYNAMICALLY BY EACH DRIVER DURING INITIALIZATION.
+; THE TABLE IS PREFIXED BY TWO BYTES.  TABLE - 1 CONTAINS THE CURRENT
+; NUMBER OF ENTRIES.  TABLE - 2 CONTAINS THE MAXIMUM NUMBER OF ENTRIES.
+; EACH ENTRY IS DEFINED AS:
+;
+;	BYTE	DEVICE TYPE ID
+;	BYTE	DEVICE/DRIVER UNIT NUMBER
+;	WORD	UNIT DATA ADDRESS
+;
+VDA_MAX	.EQU	16			; UP TO 16 UNITS
+VDA_SIZ	.EQU	VDA_MAX * 4		; EACH ENTRY IS 4 BYTES
+;
+	.DB	VDA_MAX			; MAX ENTRY COUNT TABLE PREFIX
+VDA_CNT	.DB	0			; ENTRY COUNT PREFIX
+VDA_TBL	.FILL	VDA_SIZ,0		; SPACE FOR ENTRIES
+;
+; ADD AN ENTRY TO THE VDA UNIT TABLE (SEE HB_ADDENT FOR DETAILS)
+;
+VDA_ADDENT:
+	LD	HL,VDA_TBL		; POINT TO VDA TABLE
+	JP	HB_ADDENT		; ... AND GO TO COMMON CODE
+;
 ;==================================================================================================
 ;   SYSTEM FUNCTION DISPATCHER
 ;==================================================================================================
@@ -1276,6 +1331,8 @@ SYS_GET:
 	JR	Z,SYS_GETCIOCNT
 	CP	BF_SYSGET_DIOCNT
 	JR	Z,SYS_GETDIOCNT
+	CP	BF_SYSGET_VDACNT
+	JR	Z,SYS_GETVDACNT
 	CP	BF_SYSGET_BOOTINFO
 	JR	Z,SYS_GETBOOTINFO
 	CP	BF_SYSGET_CPUINFO
@@ -1353,6 +1410,14 @@ SYS_GETDIOCNT:
 	XOR	A		; SIGNALS SUCCESS
 	RET
 ;
+; GET VIDEO UNIT COUNT
+;
+SYS_GETVDACNT:
+	LD	A,(VDA_CNT)	; GET DEVICE COUNT (FIRST BYTE OF LIST)
+	LD	E,A		; PUT IT IN E
+	XOR	A		; SIGNALS SUCCESS
+	RET
+;
 ; SET SYSTEM PARAMETERS
 ; PARAMETER(S) TO SET INDICATED IN C
 ;
@@ -1997,7 +2062,10 @@ PRTSUM:
 	LD	C,BF_SYSGET_DIOCNT	; SUBFUNC: DISK UNIT COUNT
 	RST	08			; E := DISK UNIT COUNT
 	LD	B,E			; MOVE TO B FOR LOOP COUNT
-	LD	C,0			; D WILL BE UNIT INDEX
+	LD	A,E			; MOVE TO ACCUM
+	OR	A			; SET FLAGS
+	JR	Z,PRTSUM1A		; IF NONE, BYPASS
+	LD	C,0			; C WILL BE UNIT INDEX
 PRTSUM1:
 	PUSH	BC			; SAVE LOOP CONTROL
 	CALL	PS_DISK			; PRINT DISK INFO
@@ -2005,19 +2073,41 @@ PRTSUM1:
 	INC	C			; BUMP DISK UNIT INDEX
 	DJNZ	PRTSUM1			; LOOP THRU ALL DISK DEVICES
 ;
+PRTSUM1A:
 	; PRINT SERIAL DEVICES
 	LD	B,BF_SYSGET		; FUNC: SYSTEM INFO GET
-	LD	C,BF_SYSGET_CIOCNT	; SUBFUNC: DISK UNIT COUNT
-	RST	08			; E := DISK UNIT COUNT
+	LD	C,BF_SYSGET_CIOCNT	; SUBFUNC: SERIAL UNIT COUNT
+	RST	08			; E := SERIAL UNIT COUNT
 	LD	B,E			; MOVE TO B FOR LOOP COUNT
-	LD	C,0			; D WILL BE UNIT INDEX
+	LD	A,E			; MOVE TO ACCUM
+	OR	A			; SET FLAGS
+	JR	Z,PRTSUM2A		; IF NONE, BYPASS
+	LD	C,0			; C WILL BE UNIT INDEX
 PRTSUM2:
 	PUSH	BC			; SAVE LOOP CONTROL
 	CALL	PS_SERIAL		; PRINT SERIAL INFO
 	POP	BC			; RESTORE LOOP CONTROL
-	INC	C			; BUMP DISK UNIT INDEX
-	DJNZ	PRTSUM2			; LOOP THRU ALL DISK DEVICES
+	INC	C			; BUMP SERIAL UNIT INDEX
+	DJNZ	PRTSUM2			; LOOP THRU ALL SERIAL DEVICES
+;
+PRTSUM2A:
+	; PRINT VIDEO DEVICES
+	LD	B,BF_SYSGET		; FUNC: SYSTEM INFO GET
+	LD	C,BF_SYSGET_VDACNT	; SUBFUNC: VIDEO UNIT COUNT
+	RST	08			; E := SERIAL UNIT COUNT
+	LD	B,E			; MOVE TO B FOR LOOP COUNT
+	LD	A,E			; MOVE TO ACCUM
+	OR	A			; SET FLAGS
+	JR	Z,PRTSUM3A		; IF NONE, BYPASS
+	LD	C,0			; C WILL BE UNIT INDEX
+PRTSUM3:
+	PUSH	BC			; SAVE LOOP CONTROL
+	CALL	PS_VIDEO		; PRINT VIDEO INFO
+	POP	BC			; RESTORE LOOP CONTROL
+	INC	C			; BUMP VIDEO UNIT INDEX
+	DJNZ	PRTSUM3			; LOOP THRU ALL VIDEO DEVICES
 ;
+PRTSUM3A:
 	RET				; DONE
 ;
 ; PRINT ONE LINE DISK UNIT/DEVICE INFO, DISK UNIT INDEX IN C
@@ -2072,28 +2162,6 @@ PS_PRTDT1:
 	SUB	C
 	CALL	PS_PAD			; PAD N SPACES (SPECIFIED IN A)
 	RET
-
-
-	;LD	A,D
-	;RRCA				; TYPE IS IN UPPER NIBBLE, MOVE TO LOWER NIBBLE
-	;RRCA
-	;RRCA
-	;RRCA
-	;RLCA				; X2 FOR WORD OFFSET IN STRING TABLE
-	;CALL	ADDHLA
-	;LD	A,(HL)
-	;INC	HL
-	;LD	H,(HL)
-	;LD	L,A
-
-	;CALL	PS_PRT			; PRINT $ TERM STRING AT (HL), C:=CHARS PRINTED
-	;LD	A,E			; NUM
-	;CALL	PRTDECB			; PRINT NUM, ASSUME 1 CHAR
-	;CALL	PC_COLON		; PRINT COLON
-	;LD	A,12 - 2		; 12 CHAR FIELD - 1 POS FOR UNIT NUM AND 1 POS FOR COLON	
-	;SUB	C
-	;CALL	PS_PAD			; PAD N SPACES (SPECIFIED IN A)
-	;RET
 ;
 ; PRINT DISK CAPACITY (UNIT IN C, ATTRIBUTE IN E)
 ;
@@ -2188,22 +2256,7 @@ PS_PRTDC2C:
 ;
 	RET				; DONE
 ;
-; FLOPPY ATTRIBUTE STRINGS
-;
-PS_FLP8		.TEXT	"8\", $"
-PS_FLP5		.TEXT	"5.25\", $"
-PS_FLP3		.TEXT	"3.5\", $"
-PS_FLPN		.TEXT	"???\", $"
-;
-PS_FLPSS	.TEXT	"SS/$"
-PS_FLPDS	.TEXT	"SS/$"
-;
-PS_FLPSD	.TEXT	"SD$"
-PS_FLPDD	.TEXT	"DD$"
-PS_FLPHD	.TEXT	"HD$"
-PS_FLPED	.TEXT	"ED$"
-;
-; PRINT ONE LINE SERIAL UNIT/DEVICE INFO, DISK UNIT INDEX IN C
+; PRINT ONE LINE SERIAL UNIT/DEVICE INFO, SERIAL UNIT INDEX IN C
 ;
 PS_SERIAL:
 	PUSH	BC			; SAVE UNIT INDEX FOR LATER
@@ -2258,6 +2311,50 @@ PS_PRTSC:
 	RET
 
 ;
+; PRINT ONE LINE VIDEO UNIT/DEVICE INFO, VIDEO UNIT INDEX IN C
+;
+PS_VIDEO:
+	PUSH	BC			; SAVE UNIT INDEX FOR LATER
+;
+	; UNIT COLUMN
+	PRTS("Video $")
+	LD	A,C			; MOVE UNIT NUM TO A
+	CALL	PRTDECB			; PRINT IT, ASSUME SINGLE DIGIT
+	PRTS("     $")			; PAD TO NEXT COLUMN
+;
+	; DEVICE COLUMN
+	LD	B,BF_VDADEV		; FUNC=GET DEVICE INFO, UNIT NUM STILL IN C
+	RST	08			; DE:=DEVTYP/NUM, H:=DISK ATTRIBUTES
+	PUSH	BC			; SAVE ATTRIBUTES
+	LD	HL,PS_VDSTRREF		; POINT TO VIDEO DEVICE TYPE NAME TABLE
+	CALL	PS_PRTDEV		; PRINT VIDEO DEVICE NMEMONIC PADDED TO FIELD WIDTH
+	POP	DE			; RECOVER ATTRIBUTES
+	PUSH	DE			; SAVE ATTRIBUTES AGAIN
+	CALL	PS_PRTVT		; PRINT VIDEO TYPE
+	POP	DE			; RESTORE ATTRIBUTES
+	POP	BC			; RESTORE UNIT NUM
+	CALL	PS_PRTVC		; PRINT VIDEO CONFIG
+;
+	CALL	NEWLINE
+	RET
+;
+; PRINT VIDEO TYPE (VIDEO ATTRIBUTE IN E)
+;
+PS_PRTVT:
+	LD	HL,PS_VTDUMMY
+	CALL	PS_PRT			; PRINT $ TERM STRING AT (HL), C:=CHARS PRINTED
+	LD	A,18			; 18 CHAR FIELD
+	SUB	C
+	CALL	PS_PAD			; PAD N SPACES (SPECIFIED IN A)
+	RET
+;
+; PRINT VIDEO CONFIG (UNIT IN C, ATTRIBUTE IN E)
+;
+PS_PRTVC:
+	LD	HL,PS_VCDUMMY
+	CALL	PS_PRT
+	RET
+;
 ; PRINT DEVICE NMEMONIC, DEVTYP/NUM SPECIFIED IN DE
 ;
 PS_PRTDEV:
@@ -2343,6 +2440,21 @@ PS_DTRAM	.TEXT	"RAM Disk$"
 PS_DTRF		.TEXT	"RAM Floppy$"
 PS_DTOTHER	.TEXT	"???$"
 ;
+; FLOPPY ATTRIBUTE STRINGS
+;
+PS_FLP8		.TEXT	"8\", $"
+PS_FLP5		.TEXT	"5.25\", $"
+PS_FLP3		.TEXT	"3.5\", $"
+PS_FLPN		.TEXT	"???\", $"
+;
+PS_FLPSS	.TEXT	"SS/$"
+PS_FLPDS	.TEXT	"SS/$"
+;
+PS_FLPSD	.TEXT	"SD$"
+PS_FLPDD	.TEXT	"DD$"
+PS_FLPHD	.TEXT	"HD$"
+PS_FLPED	.TEXT	"ED$"
+;
 ; SERIAL DEVICE STRINGS
 ;
 PS_SDSTRREF:
@@ -2362,6 +2474,24 @@ PS_SDPPPCON		.TEXT	"PPPCON$"
 ;
 PS_STDUMMY	.TEXT	"--$"
 ;
+; VIDEO DEVICE STRINGS
+;
+PS_VDSTRREF:
+	.DW	PS_VDVDU, PS_VDCVDU, PS_VDUPD7220, PS_VDSCG
+;
+PS_VDVDU		.TEXT	"VDU$"
+PS_VDCVDU		.TEXT	"CVDU$"
+PS_VDUPD7220		.TEXT	"UPD7220$"
+PS_VDSCG		.TEXT	"SCG$"
+;
+; SERIAL TYPE STRINGS
+;
+PS_VTDUMMY	.TEXT	"--$"
+;
+; VIDEO CONFIG STRINGS
+;
+PS_VCDUMMY	.TEXT	"--$"
+;
 ;
 ;			 0         1         2         3         4         5         6         7
 ;                        01234567890123456789012345678901234567890123456789012345678901234567890123456789
diff --git a/Source/HBIOS/hbios.inc b/Source/HBIOS/hbios.inc
index b6958533..bcfe89e0 100644
--- a/Source/HBIOS/hbios.inc
+++ b/Source/HBIOS/hbios.inc
@@ -39,17 +39,18 @@ BF_VDA		.EQU	$40
 BF_VDAINI	.EQU	BF_VDA + 0	; INITIALIZE VDU
 BF_VDAQRY	.EQU	BF_VDA + 1	; QUERY VDU STATUS
 BF_VDARES	.EQU	BF_VDA + 2	; SOFT RESET VDU
-BF_VDASCS	.EQU	BF_VDA + 3	; SET CURSOR STYLE
-BF_VDASCP	.EQU	BF_VDA + 4	; SET CURSOR POSITION
-BF_VDASAT	.EQU	BF_VDA + 5	; SET CHARACTER ATTRIBUTE
-BF_VDASCO	.EQU	BF_VDA + 6	; SET CHARACTER COLOR
-BF_VDAWRC	.EQU	BF_VDA + 7	; WRITE CHARACTER
-BF_VDAFIL	.EQU	BF_VDA + 8	; FILL
-BF_VDACPY	.EQU	BF_VDA + 9	; COPY
-BF_VDASCR	.EQU	BF_VDA + 10	; SCROLL
-BF_VDAKST	.EQU	BF_VDA + 11	; GET KEYBOARD STATUS
-BF_VDAKFL	.EQU	BF_VDA + 12	; FLUSH KEYBOARD BUFFER
-BF_VDAKRD	.EQU	BF_VDA + 13	; READ KEYBOARD
+BF_VDADEV	.EQU	BF_VDA + 3	; DEVICE INFO
+BF_VDASCS	.EQU	BF_VDA + 4	; SET CURSOR STYLE
+BF_VDASCP	.EQU	BF_VDA + 5	; SET CURSOR POSITION
+BF_VDASAT	.EQU	BF_VDA + 6	; SET CHARACTER ATTRIBUTE
+BF_VDASCO	.EQU	BF_VDA + 7	; SET CHARACTER COLOR
+BF_VDAWRC	.EQU	BF_VDA + 8	; WRITE CHARACTER
+BF_VDAFIL	.EQU	BF_VDA + 9	; FILL
+BF_VDACPY	.EQU	BF_VDA + 10	; COPY
+BF_VDASCR	.EQU	BF_VDA + 11	; SCROLL
+BF_VDAKST	.EQU	BF_VDA + 12	; GET KEYBOARD STATUS
+BF_VDAKFL	.EQU	BF_VDA + 13	; FLUSH KEYBOARD BUFFER
+BF_VDAKRD	.EQU	BF_VDA + 14	; READ KEYBOARD
 ;
 BF_SYS		.EQU	$F0
 BF_SYSSETBNK	.EQU	BF_SYS + 0	; SET CURRENT BANK
@@ -66,7 +67,7 @@ BF_POKE		.EQU	BF_SYS + 10	; PUT A BYTE TO ALT BANK
 ;
 BF_SYSGET_CIOCNT	.EQU	$00	; GET CHAR UNIT COUNT
 BF_SYSGET_DIOCNT	.EQU	$10	; GET DISK UNIT COUNT
-BF_SYSGET_VDACNT	.EQU	$10	; GET VDA UNIT COUNT
+BF_SYSGET_VDACNT	.EQU	$40	; GET VDA UNIT COUNT
 BF_SYSGET_BOOTINFO	.EQU	$E0	; GET BOOT INFORMATION
 BF_SYSGET_CPUINFO	.EQU	$F0	; GET CPU INFORMATION
 BF_SYSGET_MEMINFO	.EQU	$F1	; GET MEMORY CAPACTITY INFO
@@ -103,11 +104,11 @@ DIODEV_HDSK	.EQU	$90
 ;
 ; VDA DEVICE IDS
 ;
-VDADEV_NONE	.EQU	$00		; NO VDA DEVICE
-VDADEV_VDU	.EQU	$10		; ECB VDU - 6545 CHIP
-VDADEV_CVDU	.EQU	$20		; ECB COLOR VDU - 8563 CHIP (NOT IMP)
-VDADEV_UPD7220	.EQU	$30		; ECB uP7220 (NOT IMPLEMENTED)
-VDADEV_SCG	.EQU	$40		; N8 ONBOARD VDA SUBSYSTEM
+;VDADEV_NONE	.EQU	$00		; NO VDA DEVICE
+VDADEV_VDU	.EQU	$00		; ECB VDU - 6545 CHIP
+VDADEV_CVDU	.EQU	$10		; ECB COLOR VDU - 8563 CHIP (NOT IMP)
+VDADEV_UPD7220	.EQU	$20		; ECB uP7220 (NOT IMPLEMENTED)
+VDADEV_SCG	.EQU	$30		; N8 ONBOARD VDA SUBSYSTEM
 ;
 ; EMULATION TYPES
 ;
diff --git a/Source/HBIOS/scg.asm b/Source/HBIOS/scg.asm
index 398dcbb5..9121e4e1 100644
--- a/Source/HBIOS/scg.asm
+++ b/Source/HBIOS/scg.asm
@@ -37,13 +37,18 @@ SCG_INIT:
 ;
 	CALL 	SCG_CRTINIT		; SETUP THE SCG CHIP REGISTERS
 	CALL	SCG_LOADFONT		; LOAD FONT DATA FROM ROM TO SCG STRORAGE
+;
+	; ADD OURSELVES TO VDA DISPATCH TABLE
+	LD	B,0			; PHYSICAL UNIT IS ZERO
+	LD	C,VDADEV_SCG		; DEVICE TYPE
+	LD	DE,0			; UNIT DATA BLOB ADDRESS
+	CALL	VDA_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
 ;
 	; ADD OURSELVES TO CIO DISPATCH TABLE
 	LD	B,0			; PHYSICAL UNIT IS ZERO
 	LD	C,CIODEV_SCG		; DEVICE TYPE
 	LD	DE,0			; UNIT DATA BLOB ADDRESS
 	CALL	CIO_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
-	;LD	(SCG_CIOUNIT),A	; SAVE IT LOCALLY
 	LD	(HCB + HCB_CRTDEV),A	; SET OURSELVES AS THE CRT DEVICE
 	
 	LD	D,VDAEMU		; DEFAULT EMULATION
@@ -72,27 +77,29 @@ SCG_DISPATCH:
 	DEC	A
 	JP	Z,SCG_VDARES	; $42
 	DEC	A
-	JP	Z,SCG_VDASCS	; $43
+	JP	Z,SCG_VDADEV	; $43
+	DEC	A
+	JP	Z,SCG_VDASCS	; $44
 	DEC	A
-	JP	Z,SCG_VDASCP	; $44
+	JP	Z,SCG_VDASCP	; $45
 	DEC	A
-	JP	Z,SCG_VDASAT	; $45
+	JP	Z,SCG_VDASAT	; $46
 	DEC	A
-	JP	Z,SCG_VDASCO	; $46
+	JP	Z,SCG_VDASCO	; $47
 	DEC	A
-	JP	Z,SCG_VDAWRC	; $47
+	JP	Z,SCG_VDAWRC	; $48
 	DEC	A
-	JP	Z,SCG_VDAFIL	; $48
+	JP	Z,SCG_VDAFIL	; $49
 	DEC	A
-	JP	Z,SCG_VDACPY	; $49
+	JP	Z,SCG_VDACPY	; $4A
 	DEC	A
-	JP	Z,SCG_VDASCR	; $4A
+	JP	Z,SCG_VDASCR	; $4B
 	DEC	A
-	JP	Z,PPK_STAT	; $4B
+	JP	Z,PPK_STAT	; $4C
 	DEC	A
-	JP	Z,PPK_FLUSH	; $4C
+	JP	Z,PPK_FLUSH	; $4D
 	DEC	A
-	JP	Z,PPK_READ	; $4D
+	JP	Z,PPK_READ	; $4E
 	CALL	PANIC
 
 SCG_VDAINI:
@@ -103,8 +110,6 @@ SCG_VDAINI:
 
 	; INITIALIZE EMULATION
 	LD	B,D			; EMULATION TYPE TO B
-	;LD	A,(SCG_CIOUNIT)		; CIO UNIT NUMBER
-	;LD	C,A			; ... IS PASSED IN C
 	LD	C,CIODEV_SCG		; PASS OUR DEVICE TYPE IN C
 	LD	DE,SCG_DISPATCH		; DISPATCH ADDRESS TO DE
 	CALL	EMU_INIT		; INITIALIZE EMULATION, DE := CIO DISPATCHER
@@ -121,6 +126,12 @@ SCG_VDAQRY:
 	LD	HL,0		; EXTRACTION OF CURRENT BITMAP DATA NOT SUPPORTED YET
 	XOR	A		; SIGNAL SUCCESS
 	RET
+
+SCG_VDADEV:
+	LD	D,VDADEV_SCG	; D := DEVICE TYPE
+	LD	E,C		; E := PHYSICAL UNIT
+	XOR	A		; SIGNAL SUCCESS
+	RET
 	
 SCG_VDARES:
 	LD	DE,0			; ROW = 0, COL = 0
@@ -598,8 +609,6 @@ SCG_BLKCPY3:
 ;   SCG DRIVER - DATA
 ;==================================================================================================
 ;
-;SCG_CIOUNIT	.DB	$FF	; LOCAL COPY OF OUR CIO UNIT NUMBER
-;
 SCG_POS		.DW 	0	; CURRENT DISPLAY POSITION
 SCG_CURSAV	.DB	0	; SAVES ORIGINAL CHARACTER UNDER CURSOR
 SCG_BUF		.FILL	256,0	; COPY BUFFER
diff --git a/Source/HBIOS/tty.asm b/Source/HBIOS/tty.asm
index 1141d59f..3a7466e1 100644
--- a/Source/HBIOS/tty.asm
+++ b/Source/HBIOS/tty.asm
@@ -15,7 +15,7 @@
 ;
 TTY_INIT:
 	; SAVE CALLING VDA DRIVER'S CIO UNIT NUMBER AND VDA DISPATCH ADDRESS
-	LD	C,A			; VDA DRIVER'S DEVICE TYPE
+	LD	A,C			; VDA DRIVER'S DEVICE TYPE
 	LD	(TTY_DEVTYPE),A		; ... SAVED LOCALLY
 	LD	(TTY_VDADISPADR),DE	; ALSO SAVE VDA DRIVER'S DISPATCH ADDRESS
 	LD	DE,TTY_DISPATCH		; RETURN OUR DISPATCH ADDRESS
diff --git a/Source/HBIOS/vdu.asm b/Source/HBIOS/vdu.asm
index 4120e2d5..c9572004 100644
--- a/Source/HBIOS/vdu.asm
+++ b/Source/HBIOS/vdu.asm
@@ -33,13 +33,18 @@ VDU_INIT:
 	CALL	PRTHEXBYTE
 ;
 	CALL 	VDU_CRTINIT		; INIT SY6845 VDU CHIP
+;
+	; ADD OURSELVES TO VDA DISPATCH TABLE
+	LD	B,0			; PHYSICAL UNIT IS ZERO
+	LD	C,VDADEV_VDU		; DEVICE TYPE
+	LD	DE,0			; UNIT DATA BLOB ADDRESS
+	CALL	VDA_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
 ;
 	; ADD OURSELVES TO CIO DISPATCH TABLE
 	LD	B,0			; PHYSICAL UNIT IS ZERO
 	LD	C,CIODEV_VDU		; DEVICE TYPE
 	LD	DE,0			; UNIT DATA BLOB ADDRESS
 	CALL	CIO_ADDENT		; ADD ENTRY, A := UNIT ASSIGNED
-	;LD	(VDU_CIOUNIT),A		; SAVE IT LOCALLY
 	LD	(HCB + HCB_CRTDEV),A	; SET OURSELVES AS THE CRT DEVICE
 	
 	LD	D,VDAEMU		; DEFAULT EMULATION
@@ -68,27 +73,29 @@ VDU_DISPATCH:
 	DEC	A
 	JR	Z,VDU_VDARES	; $42
 	DEC	A
-	JR	Z,VDU_VDASCS	; $43
+	JR	Z,VDU_VDADEV	; $43
 	DEC	A
-	JR	Z,VDU_VDASCP	; $44
+	JR	Z,VDU_VDASCS	; $44
 	DEC	A
-	JR	Z,VDU_VDASAT	; $45
+	JR	Z,VDU_VDASCP	; $45
 	DEC	A
-	JR	Z,VDU_VDASCO	; $46
+	JR	Z,VDU_VDASAT	; $46
 	DEC	A
-	JR	Z,VDU_VDAWRC	; $47
+	JR	Z,VDU_VDASCO	; $47
 	DEC	A
-	JR	Z,VDU_VDAFIL	; $48
+	JR	Z,VDU_VDAWRC	; $48
 	DEC	A
-	JR	Z,VDU_VDACPY	; $49
+	JR	Z,VDU_VDAFIL	; $49
 	DEC	A
-	JR	Z,VDU_VDASCR	; $4A
+	JR	Z,VDU_VDACPY	; $4A
 	DEC	A
-	JP	Z,PPK_STAT	; $4B
+	JR	Z,VDU_VDASCR	; $4B
 	DEC	A
-	JP	Z,PPK_FLUSH	; $4C
+	JP	Z,PPK_STAT	; $4C
 	DEC	A
-	JP	Z,PPK_READ	; $4D
+	JP	Z,PPK_FLUSH	; $4D
+	DEC	A
+	JP	Z,PPK_READ	; $4E
 	CALL	PANIC
 
 VDU_VDAINI:
@@ -99,8 +106,6 @@ VDU_VDAINI:
 
 	; INITIALIZE EMULATION
 	LD	B,D			; EMULATION TYPE TO B
-	;LD	A,(VDU_CIOUNIT)		; CIO UNIT NUMBER
-	;LD	C,A			; ... IS PASSED IN C
 	LD	C,CIODEV_VDU		; PASS OUR DEVICE TYPE IN C
 	LD	DE,VDU_DISPATCH		; DISPATCH ADDRESS TO DE
 	CALL	EMU_INIT		; INITIALIZE EMULATION, DE := CIO DISPATCHER
@@ -127,7 +132,13 @@ VDU_VDARES:
 
 	XOR	A
 	RET
-	
+
+VDU_VDADEV:
+	LD	D,VDADEV_VDU	; D := DEVICE TYPE
+	LD	E,C		; E := PHYSICAL UNIT
+	XOR	A		; SIGNAL SUCCESS
+	RET
+
 VDU_VDASCS:
 	CALL	PANIC		; NOT IMPLEMENTED (YET)
 	
@@ -469,8 +480,6 @@ VDU_RSCROLL:
 ;   VDU DRIVER - DATA
 ;==================================================================================================
 ;
-;VDU_CIOUNIT	.DB	$FF		; LOCAL COPY OF OUR CIO UNIT NUMBER
-;
 VDU_POS		.DW 	0		; CURRENT DISPLAY POSITION
 VDU_OFFSET	.DW 	0		; CURRENT DISPLAY POSITION
 VDU_BUF		.FILL	256,0		; COPY BUFFER