diff --git a/Doc/RomWBW Applications.pdf b/Doc/RomWBW Applications.pdf
index 9b936839..df2425ce 100644
Binary files a/Doc/RomWBW Applications.pdf and b/Doc/RomWBW Applications.pdf differ
diff --git a/Doc/RomWBW Architecture.pdf b/Doc/RomWBW Architecture.pdf
index 5c44e59f..8a35983b 100644
Binary files a/Doc/RomWBW Architecture.pdf and b/Doc/RomWBW Architecture.pdf differ
diff --git a/Doc/RomWBW Disk Catalog.pdf b/Doc/RomWBW Disk Catalog.pdf
index 4ee85ddf..e1dedd0b 100644
Binary files a/Doc/RomWBW Disk Catalog.pdf and b/Doc/RomWBW Disk Catalog.pdf differ
diff --git a/Doc/RomWBW Getting Started.pdf b/Doc/RomWBW Getting Started.pdf
index 90f6e84b..598da351 100644
Binary files a/Doc/RomWBW Getting Started.pdf and b/Doc/RomWBW Getting Started.pdf differ
diff --git a/Source/Apps/XM/xmx.180 b/Source/Apps/XM/xmx.180
index a07cfa68..479a3dfb 100644
--- a/Source/Apps/XM/xmx.180
+++ b/Source/Apps/XM/xmx.180
@@ -61,14 +61,74 @@ MINIT:
 	CALL	IDBIO		; 1=HBIOS, 2=UBIOS
 	LD	(BIOID),A	; Save it
 	DEC	A		; Test for HBIOS
-	JR	Z,HINIT		; Do HBIOS setup
+	JR	Z,MINIT_HB	; Do HBIOS setup
 	DEC	A		; Test for UBIOS
-	JR	Z,UINIT		; Do UBIOS setup
+	JR	Z,MINIT_UB	; Do UBIOS setup
 ;
 	; Neither UNA nor RomWBW
 	LD	DE,ERR_BIO	; BIOS error message
 	JP	FAIL		; Print msg and bail out
 ;
+MINIT_HB:
+	; Display RomWBW notification string
+	LD	DE,HB_TAG	; BIOS notification string
+	LD	C,9		; BDOS string display function
+	CALL	BDOS		; Do it
+;
+	; Get CPU speed from RomWBW HBIOS and save it
+	LD	B,0F8H		; HBIOS SYSGET function 0xF8
+	LD	C,0F0H		; CPUINFO subfunction 0xF0
+	RST	08		; Do it, L := CPU speed in MHz
+	LD	A,L		; Move it to A
+	LD	(CPUSPD),A	; Save it
+;
+	; Get HBIOS bank id
+	LD	BC,0F8F2H	; HBIOS SYSGET, Bank Info
+	RST	08		; do it
+	JP	NZ,APIERR	; handle API error
+	LD	A,D		; BIOS bank id to A
+	LD	(BIOSBID),A	; save it
+;
+	; Lookup current console to use as default for transfer
+	LD	B,0FAH		; HBIOS PEEK
+	LD	A,(BIOSBID)	; get BIOS bank id
+	LD	D,A		; ... and put in D
+	LD	HL,100H + 12H	; HCB console unit address
+	RST	08		; E := value
+	LD	A,E		; put in A
+	LD	(UNIT),A	; save it
+;
+	; Get HBIOS character 0 device type
+	LD	B,006H		; HBIOS DEVICE function 0x06
+	LD	C,000H		; HBIOS char 0 device
+	RST	08		; Do it, D=device type
+	LD	A,D		; Put result in A
+	CP	000H		; UART?
+	JP	Z,UA_INIT	; If so, do UART H/W init
+	CP	080H		; USB-FIFO?
+	JP	Z,UF_INIT	; If so, do USB-FIFO H/W init
+	JP	HB_INIT		; Otherwise, use BIOS I/O
+;
+MINIT_UB:
+	; Display UNA notification string
+	LD	DE,UB_TAG	; BIOS notification string
+	LD	C,9		; BDOS string display function
+	CALL	BDOS		; Do it
+;
+	; Get CPU speed from UNA and save it
+	LD	C,0F8H		; UNA BIOS Get PHI function
+	RST	08		; Returns speed in Hz in DE:HL
+	LD	B,4		; Divide MHz in DE:HL by 100000H
+MINIT_UB1:
+	SRL	D		; ... to get approx CPU speed in
+	RR	E		; ...MHz.  Throw away HL, and
+	DJNZ	MINIT_UB1	; ...right shift DE by 4.
+	INC	E		; Fix up for value truncation
+	LD	A,E		; Put in A
+	LD	(CPUSPD),A	; Save it
+;
+	JP	UB_INIT		; UNA BIOS init
+;
 MINIT_RET:
 	PUSH	HL		; Save HL (JP table adr)
 
@@ -107,45 +167,35 @@ MINIT_RET:
 	LD	HL,(RCVSCL)	; HL := receive scalar
 	RET			; and return
 ;
-HINIT:
-	; Display RomWBW notification string
-	LD	DE,HBTAG	; BIOS notification string
-	LD	C,9		; BDOS string display function
-	CALL	BDOS		; Do it
-;
-	; Get CPU speed from RomWBW HBIOS and save it
-	LD	B,0F8H		; HBIOS SYSGET function 0xF8
-	LD	C,0F0H		; CPUINFO subfunction 0xF0
-	RST	08		; Do it, L := CPU speed in MHz
-	LD	A,L		; Move it to A
-	LD	(CPUSPD),A	; Save it
-;
-	JP	H_INIT		; HBIOS init
+;-----------------------------------------------------------------------
 ;
-UINIT:
-	; Display UNA notification string
-	LD	DE,UBTAG	; BIOS notification string
-	LD	C,9		; BDOS string display function
-	CALL	BDOS		; Do it
+; Uninitialize modem
 ;
-	; Get CPU speed from UNA and save it
-	LD	C,0F8H		; UNA BIOS Get PHI function
-	RST	08		; Returns speed in Hz in DE:HL
-	LD	B,4		; Divide MHz in DE:HL by 100000H
-UINIT1:
-	SRL	D		; ... to get approx CPU speed in
-	RR	E		; ...MHz.  Throw away HL, and
-	DJNZ	UINIT1		; ...right shift DE by 4.
-	INC	E		; Fix up for value truncation
-	LD	A,E		; Put in A
-	LD	(CPUSPD),A	; Save it
+UNINIT:
+	LD	A,(BIOID)
+	CP	1		; Is HBIOS?
+	JR	Z,HUNINIT	; Handle HBIOS
+	CP	2		; Is UBIOS?
+	JR	Z,UUNINIT	; Handle UBIOS
+	RET			; Just return
 ;
-	JP	U_INIT		; UNA BIOS init
+HUNINIT:
+	; HBIOS: Reset character device 0
+	LD	B,04H		; HBIOS CIOINIT function 0x04
+	LD	A,(UNIT)	; HBIOS serial unit number
+	LD	C,A		; Put in C for func call
+	LD	DE,-1		; Reset w/ current settings
+	RST	08		; Do it
+	RET			; not initialized, so no 'UN-INITIALIZE'
 ;
-HWERR:
-	; Failed to identify target comm hardware
-	LD	DE,ERR_HW	; Hardware error message
-	JP	FAIL		; Print message and bail out
+UUNINIT:
+	; UBIOS: Reset character device 0
+	LD	C,10H		; UNA INIT function 0x10
+	LD	A,(UNIT)	; UBIOS serial unit number
+	LD	B,A		; Put in B for func call
+	LD	DE,-1		; Reset w/ current settings
+	RST	08		; Do it
+	RET			; not initialized, so no 'UN-INITIALIZE'
 ;
 ; Identify active BIOS.	 RomWBW HBIOS=1, UNA UBIOS=2, else 0
 ;
@@ -184,6 +234,16 @@ IDBIO2:
 	XOR	A		; Setup return value of 0
 	RET			; and done
 ;
+HWERR:
+	; Failed to identify target comm hardware
+	LD	DE,ERR_HW	; Hardware error message
+	JP	FAIL		; Print message and bail out
+;
+APIERR:
+	; API returned unepected failure
+	LD	DE,ERR_API	; API error message
+	JP	FAIL		; Pprint message and bail out
+;
 FAIL:
 	; DE has error string address
 	LD	C,9		; BDOS string display function
@@ -192,36 +252,6 @@ FAIL:
 ;
 ;-----------------------------------------------------------------------
 ;
-; Uninitialize modem
-;
-UNINIT:
-	LD	A,(BIOID)
-	CP	1		; Is HBIOS?
-	JR	Z,H_UNINIT	; Handle HBIOS
-	CP	2		; Is UBIOS?
-	JR	Z,U_UNINIT	; Handle UBIOS
-	RET			; Just return
-;
-H_UNINIT:
-	; HBIOS: Reset character device 0
-	LD	B,04H		; HBIOS CIOINIT function 0x04
-	LD	A,(UNIT)	; HBIOS serial unit number
-	LD	C,A		; Put in C for func call
-	LD	DE,-1		; Reset w/ current settings
-	RST	08		; Do it
-	RET			; not initialized, so no 'UN-INITIALIZE'
-;
-U_UNINIT:
-	; UBIOS: Reset character device 0
-	LD	C,10H		; UNA INIT function 0x10
-	LD	A,(UNIT)	; UBIOS serial unit number
-	LD	B,A		; Put in B for func call
-	LD	DE,-1		; Reset w/ current settings
-	RST	08		; Do it
-	RET			; not initialized, so no 'UN-INITIALIZE'
-;
-;-----------------------------------------------------------------------
-;
 ; The following are all dummy routines that are unused because MINIT
 ; dynamically installs the real jump table.
 ;
@@ -240,17 +270,20 @@ EXTRA3:
 BIOID	DB	0		; BIOS ID, 1=HBIOS, 2=UBIOS
 CPUSPD	DB	10		; CPU speed in MHz
 RCVSCL	DW	6600		; RECV loop timeout scalar
-UNIT	DB	0		; HBIOS serial device unit number
+UNIT	DB	0		; BIOS serial device unit number
+BIOSBID	DB	00H		; BIOS bank id
 ;
 TAG	DB	"RomWBW, 23-May-2020$"
 ;
-H_LBL	DB	", HBIOS FastPath$"
-U_LBL	DB	", UNA UBIOS$"
+HB_LBL	DB	", HBIOS FastPath$"
+UB_LBL	DB	", UNA UBIOS$"
+UA_LBL	DB	", UART$"
+UF_LBL	DB	", USB-FIFO$"
 COM_LBL	DB	" on COM$"
 EXP_LBL	DB	13, 10, 13, 10, "*** Experimental ***$"
 ;
-UBTAG	DB	" [UNA]$"
-HBTAG	DB	" [WBW]$"
+UB_TAG	DB	" [UNA]$"
+HB_TAG	DB	" [WBW]$"
 ;
 CRLF	DB	13, 10, "$"
 ;
@@ -270,38 +303,22 @@ ERR_API	DB	13, 10, 13, 10, "++ BIOS API Error ++", 13, 10, "$"
 ; table at program startup.  See MINIT above.  Note that only a
 ; subset of the jump table is overlaid (SENDR to SPEED).
 ;
-H_JPTBL:
-	JP	H_SENDR		; send character (via pop psw)
-	JP	H_CAROK		; test for carrier
-	JP	H_MDIN		; receive data byte
-	JP	H_GETCHR	; get character from modem
-	JP	H_RCVRDY	; check receive ready
-	JP	H_SNDRDY	; check send ready
-	JP	H_SPEED		; get speed value for file transfer time
+HB_JPTBL:
+	JP	HB_SENDR	; send character (via pop psw)
+	JP	HB_CAROK	; test for carrier
+	JP	HB_MDIN		; receive data byte
+	JP	HB_GETCHR	; get character from modem
+	JP	HB_RCVRDY	; check receive ready
+	JP	HB_SNDRDY	; check send ready
+	JP	HB_SPEED		; get speed value for file transfer time
 ;
 ;-----------------------------------------------------------------------
 ;
 ; HBIOS initialization
 ;
-H_INIT:
+HB_INIT:
 	LD	HL,2150		; Smaller receive loop timeout scalar
 	LD	(RCVSCL),HL	; ... to compensate for BIOS overhead
-;
-	; Get HBIOS bank id
-	LD	BC,0F8F2H	; HBIOS SYSGET, Bank Info
-	RST	08		; do it
-	JR	NZ,H_APIERR	; handle API error
-	LD	A,D		; BIOS bank id to A
-	LD	(H_BNKID),A	; save it
-;
-	; Lookup current console to use as default for transfer
-	LD	B,0FAH		; HBIOS PEEK
-	LD	A,(H_BNKID)	; get BIOS bank id
-	LD	D,A		; ... and put in D
-	LD	HL,100H + 12H	; HCB console unit address
-	RST	08		; E := value
-	LD	A,E		; put in A
-	LD	(UNIT),A	; save it
 ;
 	; Patch SENDR w/ FastPath addresses
 	LD	BC,0F801H	; Get CIO func/data adr
@@ -309,9 +326,9 @@ H_INIT:
 	LD	A,(UNIT)	; get desired char unit
 	LD	E,A		; and put in E
 	RST	08
-	JR	NZ,H_APIERR	; handle API error
-	LD	(H_UDAT),DE	; Plug in data adr
-	LD	(H_SCFN),HL	; Plug in func adr
+	JP	NZ,APIERR	; handle API error
+	LD	(HB_UDAT),DE	; Plug in data adr
+	LD	(HB_SCFN),HL	; Plug in func adr
 ;
 	; Patch GETCHR/MDIN w/ FastPath addresses
 	LD	BC,0F801H	; Get CIO func/data adr
@@ -319,8 +336,8 @@ H_INIT:
 	LD	A,(UNIT)	; get desired char unit
 	LD	E,A		; and put in E
 	RST	08
-	JR	NZ,H_APIERR	; handle API error
-	LD	(H_GCFN),HL	; Plug in func adr
+	JP	NZ,APIERR	; handle API error
+	LD	(HB_GCFN),HL	; Plug in func adr
 ;
 	; Patch RCVRDY w/ FastPath addresses
 	LD	BC,0F801H	; Get CIO func/data adr
@@ -328,8 +345,8 @@ H_INIT:
 	LD	A,(UNIT)	; get desired char unit
 	LD	E,A		; and put in E
 	RST	08
-	JR	NZ,H_APIERR	; handle API error
-	LD	(H_RRFN),HL	; Plug in func adr
+	JP	NZ,APIERR	; handle API error
+	LD	(HB_RRFN),HL	; Plug in func adr
 ;
 	; Patch SNDRDY w/ FastPath addresses
 	LD	BC,0F801H	; Get CIO func/data adr
@@ -337,31 +354,27 @@ H_INIT:
 	LD	A,(UNIT)	; get desired char unit
 	LD	E,A		; and put in E
 	RST	08
-	JR	NZ,H_APIERR	; handle API error
-	LD	(H_SRFN),HL	; Plug in func adr
+	JP	NZ,APIERR	; handle API error
+	LD	(HB_SRFN),HL	; Plug in func adr
 ;
-	LD	HL,H_JPTBL
-	LD	DE,H_LBL
+	LD	HL,HB_JPTBL
+	LD	DE,HB_LBL
 	JP	MINIT_RET
 ;
-H_APIERR:
-	LD	DE,ERR_API
-	JP	FAIL
-;
 ;-----------------------------------------------------------------------
 ;
 ; Send character on top of stack
 ;
-H_SENDR:
+HB_SENDR:
 	POP	AF		; get character to send from stack
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
 	LD	E,A		; character to E
-	LD	IY,(H_UDAT)
-	LD	A,(H_BNKID)	; call into HBIOS bank
+	LD	IY,(HB_UDAT)
+	LD	A,(BIOSBID)	; call into HBIOS bank
 	LD	IX,0000H
-H_SCFN	EQU	$-2
+HB_SCFN	EQU	$-2
 	CALL	0FFF9H		; HBIOS bank call
 	POP	HL
 	POP	DE
@@ -372,28 +385,31 @@ H_SCFN	EQU	$-2
 ;
 ; Test and report carrier status, Z set if carrier present
 ;
-H_CAROK:
+HB_CAROK:
 	XOR	A		; not used, always indicate present
 	RET
 ;
 ;-----------------------------------------------------------------------
 ;
-; Get a character (assume character ready has already been tested)
+; Get a character
 ;
-; GETCHR must NOT block.
+; GETCHR must not block
 ;
-H_GETCHR:
-	CALL	H_RCVRDY
+HB_GETCHR:
+	CALL	HB_RCVRDY
 	RET	NZ
-
-H_MDIN:
+	; Fall thru if char ready
+;
+; MDIN can assume a character is ready
+;
+HB_MDIN:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
-	LD	IY,(H_UDAT)
-	LD	A,(H_BNKID)	; call into HBIOS bank
+	LD	IY,(HB_UDAT)
+	LD	A,(BIOSBID)	; call into HBIOS bank
 	LD	IX,0000H
-H_GCFN	EQU	$-2
+HB_GCFN	EQU	$-2
 	CALL	0FFF9H		; HBIOS bank call
 	LD	A,E		; byte received to A
 	POP	HL
@@ -407,14 +423,14 @@ H_GCFN	EQU	$-2
 ; Error code returned in A register
 ; *** Error code does not seem to be used ***
 ;
-H_RCVRDY:
+HB_RCVRDY:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
-	LD	IY,(H_UDAT)
-	LD	A,(H_BNKID)	; call into HBIOS bank
+	LD	IY,(HB_UDAT)
+	LD	A,(BIOSBID)	; call into HBIOS bank
 	LD	IX,0000H
-H_RRFN	EQU	$-2
+HB_RRFN	EQU	$-2
 	CALL	0FFF9H		; HBIOS bank call
 	SUB	1		; CF set IFF zero
 	RL	A		; CF to bit 0 of A
@@ -429,14 +445,14 @@ H_RRFN	EQU	$-2
 ;
 ; Test for ready to send a character, Z = ready
 ;
-H_SNDRDY:
+HB_SNDRDY:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
-	LD	IY,(H_UDAT)
-	LD	A,(H_BNKID)	; call into HBIOS bank
+	LD	IY,(HB_UDAT)
+	LD	A,(BIOSBID)	; call into HBIOS bank
 	LD	IX,0000H
-H_SRFN	EQU	$-2
+HB_SRFN	EQU	$-2
 	CALL	0FFF9H		; HBIOS bank call
 	SUB	1		; CF set IFF zero
 	RL	A		; CF to bit 0 of A
@@ -450,14 +466,13 @@ H_SRFN	EQU	$-2
 ;
 ; Report baud rate (index into SPTBL returned in register A)
 ;
-H_SPEED:
+HB_SPEED:
 	LD	A,8		; arbitrarily return 9600 baud
 	RET
 ;
 ;
 ;
-H_BNKID	DB	00H		; HBIOS bank id
-H_UDAT	DW	0000H		; Unit data address
+HB_UDAT	DW	0000H		; Unit data address
 ;
 ;
 ;=======================================================================
@@ -472,20 +487,20 @@ H_UDAT	DW	0000H		; Unit data address
 ; table at program startup.  See MINIT above.  Note that only a
 ; subset of the jump table is overlaid (SENDR to SPEED).
 ;
-U_JPTBL:
-	JP	U_SENDR		; send character (via pop psw)
-	JP	U_CAROK		; test for carrier
-	JP	U_MDIN		; receive data byte
-	JP	U_GETCHR	; get character from modem
-	JP	U_RCVRDY	; check receive ready
-	JP	U_SNDRDY	; check send ready
-	JP	U_SPEED		; get speed value for file transfer time
+UB_JPTBL:
+	JP	UB_SENDR	; send character (via pop psw)
+	JP	UB_CAROK	; test for carrier
+	JP	UB_MDIN		; receive data byte
+	JP	UB_GETCHR	; get character from modem
+	JP	UB_RCVRDY	; check receive ready
+	JP	UB_SNDRDY	; check send ready
+	JP	UB_SPEED	; get speed value for file transfer time
 ;
 ;-----------------------------------------------------------------------
 ;
 ; UBIOS initialization
 ;
-U_INIT:
+UB_INIT:
 ;
 ; TODO:
 ;   - TEST!!!
@@ -494,15 +509,15 @@ U_INIT:
 	LD	HL,3000		; Smaller receive loop timeout scalar
 	LD	(RCVSCL),HL	; ... to compensate for BIOS overhead
 ;
-	LD	HL,U_JPTBL
-	LD	DE,U_LBL
+	LD	HL,UB_JPTBL
+	LD	DE,UB_LBL
 	JP	MINIT_RET
 ;
 ;-----------------------------------------------------------------------
 ;
 ; Send character on top of stack
 ;
-U_SENDR:
+UB_SENDR:
 	POP	AF		; get character to send from stack
 	PUSH	BC
 	PUSH	DE
@@ -519,21 +534,24 @@ U_SENDR:
 ;
 ; Test and report carrier status, Z set if carrier present
 ;
-U_CAROK:
+UB_CAROK:
 	XOR	A		; not used, always indicate present
 	RET
 ;
 ;-----------------------------------------------------------------------
 ;
-; Get a character (assume character ready has already been tested)
+; Get a character
 ;
-; GETCHR must NOT block.
+; GETCHR must not block
 ;
-U_GETCHR:
-	CALL	U_RCVRDY
+UB_GETCHR:
+	CALL	UB_RCVRDY
 	RET	NZ
-
-U_MDIN:
+	; Fall thru if char ready
+;
+; MDIN can assume a character is ready
+;
+UB_MDIN:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
@@ -551,7 +569,7 @@ U_MDIN:
 ; Error code returned in A register
 ; *** Error code does not seem to be used ***
 ;
-U_RCVRDY:
+UB_RCVRDY:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
@@ -570,7 +588,7 @@ U_RCVRDY:
 ;
 ; Test for ready to send a character, Z = ready
 ;
-U_SNDRDY:
+UB_SNDRDY:
 	PUSH	BC
 	PUSH	DE
 	PUSH	HL
@@ -588,7 +606,252 @@ U_SNDRDY:
 ;
 ; Report baud rate (index into SPTBL returned in register A)
 ;
-U_SPEED:
+UB_SPEED:
+	LD	A,8		; arbitrarily return 9600 baud
+	RET
+;
+;=======================================================================
+;=======================================================================
+;
+; 8250-like UART
+;
+;=======================================================================
+;=======================================================================
+;
+; UART constants
+;
+UA_SNDB	EQU	20H		; bit to test for send ready
+UA_SNDR	EQU	20H		; value when ready to send
+UA_RCVB	EQU	01H		; bit to test for receive ready
+UA_RCVR	EQU	01H		; value when ready to receive
+UA_PARE	EQU	04H		; bit for parity error
+UA_OVRE	EQU	02H		; bit for overrun error
+UA_FRME	EQU	08H		; bit for framing error
+UA_ERRS	EQU	UA_FRME | UA_OVRE | UA_PARE
+;
+; Following jump table is dynamically patched into real jump
+; table at program startup.  See MINIT above.  Note that only a
+; subset of the jump table is overlaid (SENDR to SPEED).
+;
+UA_JPTBL:
+	JP	UA_SENDR	; send character (via pop psw)
+	JP	UA_CAROK	; test for carrier
+	JP	UA_MDIN		; receive data byte
+	JP	UA_GETCHR	; get character from modem
+	JP	UA_RCVRDY	; check receive ready
+	JP	UA_SNDRDY	; check send ready
+	JP	UA_SPEED	; get speed value for file transfer time
+;
+;-----------------------------------------------------------------------
+;
+; UART initialization
+;
+UA_INIT:
+	LD	DE,13000	; Receive loop timeout scalar
+	LD	(RCVSCL),DE	; ... for UART RCVRDY timing
+;
+	LD	A,L		; Get base I/O port address
+	LD	(UA_SCP),A	; Set port value in SENDR
+	LD	(UA_GCP),A	; Set port value in GETCHR
+	ADD	A,5		; UART control port is 5 higher
+	LD	(UA_RRP),A	; Set port value in RCVRDY
+	LD	(UA_SRP),A	; Set port value in SNDRDY
+;
+	LD	HL,UA_JPTBL
+	LD	DE,UA_LBL
+	JP	MINIT_RET
+;
+;-----------------------------------------------------------------------
+;
+; Send character on top of stack
+;
+UA_SENDR:
+	POP	AF		; get character to send from stack
+	OUT	(0FFH),A	; send to port
+UA_SCP	EQU	$-1		; port value
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test and report carrier status, Z set if carrier present
+;
+UA_CAROK:
+	XOR	A		; not used, always indicate present
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Get a character
+;
+; GETCHR must not block
+;
+UA_GETCHR:
+	CALL	UA_RCVRDY
+	RET	NZ
+	; Fall thru if char ready
+;
+; MDIN can assume a character is ready
+;
+UA_MDIN:
+	IN	A,(0FFH)	; read character from port
+UA_GCP	EQU	$-1		; port value
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test for character ready to receive, Z = ready
+; Error code returned in A register
+; *** Error code does not seem to be used ***
+;
+UA_RCVRDY:
+	IN	A,(0FFH)	; get modem status
+UA_RRP	EQU	$-1		; port value	
+	AND	UA_RCVB		; isolate ready bit
+	CP	UA_RCVR		; test it (set flags)
+	LD	A,0		; report no line errors
+;
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test for ready to send a character, Z = ready
+;
+UA_SNDRDY:
+	IN	A,(0FFH)	; get status
+UA_SRP	EQU	$-1		; port value
+	AND	UA_SNDB		; isolate transmit ready bit
+	CP	UA_SNDR		; test for ready value
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Report baud rate (index into SPTBL returned in register A)
+;
+UA_SPEED:
+	LD	A,8		; arbitrarily return 9600 baud
+	RET
+;
+;
+;
+UA_BASE	DB	00H		; UART base port I/O address
+UA_CTLP	DB	00H		; UART control port I/O address
+;
+;
+;=======================================================================
+;=======================================================================
+;
+; WILL SOWERBUTTS ECB USB-FIFO
+;
+;=======================================================================
+;=======================================================================
+;
+UF_BASE		EQU	0CH
+UF_DATA		EQU	(UF_BASE+0)
+UF_STATUS	EQU	(UF_BASE+1)
+UF_SEND_IMM	EQU	(UF_BASE+2)
+;
+; Following jump table is dynamically patched over initial jump
+; table at program startup.  See MINIT above.  Note that only a
+; subset of the jump table is overlaid (SENDR to SPEED).
+;
+UF_JPTBL:
+	JP	UF_SENDR	; send character (via pop psw)
+	JP	UF_CAROK	; test for carrier
+	JP	UF_MDIN		; receive data byte
+	JP	UF_GETCHR	; get character from modem
+	JP	UF_RCVRDY	; check receive ready
+	JP	UF_SNDRDY	; check send ready
+	JP	UF_SPEED	; get speed value for file transfer time
+;
+;-----------------------------------------------------------------------
+;
+; USB-FIFO initialization
+;
+UF_INIT:
+	LD	HL,12000	; Receive loop timeout scalar
+	LD	(RCVSCL),HL	; ... for UART RCVRDY timing
+;
+	LD	A,L		; Get base I/O port address (data port)
+	LD	(UF_SCDP),A	; Set data port in SENDR
+	LD	(UF_GCDP),A	; Set data port in GETCHR/MDIN
+	INC	A		; Bump to status port
+	LD	(UF_RRSP),A	; Set status port in RCVRDY
+	LD	(UF_SRSP),A	; Set status port in SNDRDY
+	INC	A		; Bump to send immediate port
+	LD	(UF_SCIP),A	; Set send immed port in SENDR
+;
+	LD	HL,UF_JPTBL
+	LD	DE,UF_LBL
+	JP	MINIT_RET
+;
+;-----------------------------------------------------------------------
+;
+; Send character on top of stack
+;
+UF_SENDR:
+
+	POP	AF		; get character to send from stack
+	OUT	(0FFH),A	; write to fifo
+UF_SCDP	EQU	$-1		; data port
+	OUT	(0FFH),A	; send immediate
+UF_SCIP	EQU	$-1		; send immediate port
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test and report carrier status, Z set if carrier present
+;
+UF_CAROK:
+	XOR	A		; not used, always indicate present
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Get a character (assume character ready has already been tested)
+;
+; GETCHR must not block
+;
+UF_GETCHR:
+	CALL	UF_RCVRDY
+	RET	NZ
+	; Fall thru if char ready
+;
+; MDIN can assume a character is ready
+;
+UF_MDIN:
+	IN	A,(0FFH)	; get char
+UF_GCDP	EQU	$-1		; data port
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test for character ready to receive, Z = ready
+; Error code returned in A register
+; *** Error code does not seem to be used ***
+;
+UF_RCVRDY:
+	IN	A,(0FFH)	; b7=0 if char avail, =1 if no char.
+UF_RRSP	EQU	$-1		; status port
+	RLCA			; b0=0 if char avail, =1 if no char.
+	AND	00000001B	; a=0, zf=1 if no char, a=1, zf=0 if char avail.
+	LD	A,0
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Test for ready to send a character, Z = ready
+;
+UF_SNDRDY:
+	IN	A,(0FFH)	; bit 0=0 if space avail, =1 IF FULL
+UF_SRSP	EQU	$-1		; status port
+	AND	00000001B	; A=0, ZF=1 if space avail, A=1, ZF=0 if full.
+	RET
+;
+;-----------------------------------------------------------------------
+;
+; Report baud rate (index into SPTBL returned in register A)
+;
+UF_SPEED:
 	LD	A,8		; arbitrarily return 9600 baud
 	RET
 ;
diff --git a/Source/Doc/Architecture.md b/Source/Doc/Architecture.md
index 8f3ed193..a4c793da 100644
--- a/Source/Doc/Architecture.md
+++ b/Source/Doc/Architecture.md
@@ -558,6 +558,8 @@ unit. Register pair DE contains the line characteristics upon return.
 |       C: Serial Device Attributes
 |       D: Serial Device Type
 |       E: Serial Device Number
+|       H: Serial Device Unit Mode
+|       L: Serial Device Unit I/O Base Address
 
 Reports information about the character device unit specified. Register C
 indicates the device attributes: 0=RS-232 and 1=Terminal. Register D
@@ -954,7 +956,7 @@ Documentation required...
 
 Documentation required...
 
-### Function 0x28 -- RTC DEVICE (DIODEVICE)
+### Function 0x28 -- RTC DEVICE (RTCDEVICE)
 
 | _Entry Parameters_
 |       B: 0x28
diff --git a/Source/HBIOS/API.txt b/Source/HBIOS/API.txt
index b0396e9a..013ec895 100644
--- a/Source/HBIOS/API.txt
+++ b/Source/HBIOS/API.txt
@@ -267,6 +267,8 @@ DEVICE ($06):
                                         D=Device Type
                                         E=Device Number
 					C=Device Attributes
+					H=Device Mode
+					L=Base I/O Adr
 
   Serial Device Attributes Byte:
     7: 0=RS-232, 1=Terminal
@@ -331,6 +333,8 @@ DEVICE ($17)
                                         D=Device Type (MD, FD, IDE, etc.)
                                         E=Device Number (0..n)
 					C=Device Attributes
+					H=Device Mode
+					L=Base I/O Adr
 
   Report the Device Type (Floppy, IDE, SD, etc.) and Device Number.  Call
   does not perform any I/O and succeeds even if the device is in an error state.
diff --git a/Source/HBIOS/acia.asm b/Source/HBIOS/acia.asm
index 4c3c1255..1ca7f218 100644
--- a/Source/HBIOS/acia.asm
+++ b/Source/HBIOS/acia.asm
@@ -571,6 +571,8 @@ ACIA_DEVICE:
         LD      D,CIODEV_ACIA           ; D := DEVICE TYPE
         LD      E,(IY)                  ; E := PHYSICAL UNIT
         LD      C,$00                   ; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,(IY+3)		; L := BASE I/O ADDRESS
         XOR     A                       ; SIGNAL SUCCESS
         RET
 ;
diff --git a/Source/HBIOS/asci.asm b/Source/HBIOS/asci.asm
index 26a71d87..0a064734 100644
--- a/Source/HBIOS/asci.asm
+++ b/Source/HBIOS/asci.asm
@@ -575,6 +575,8 @@ ASCI_DEVICE:
 	LD	D,CIODEV_ASCI		; D := DEVICE TYPE
 	LD	E,(IY)			; E := PHYSICAL UNIT
 	LD	C,$00			; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,(IY+3)		; L := BASE I/O ADDRESS
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
diff --git a/Source/HBIOS/duart.asm b/Source/HBIOS/duart.asm
index af716ece..dda23fa2 100644
--- a/Source/HBIOS/duart.asm
+++ b/Source/HBIOS/duart.asm
@@ -611,10 +611,12 @@ DUART_QUERY:
 ;
 ;
 DUART_DEVICE:
-	LD	D,CIODEV_DUART	; D := DEVICE TYPE
-	LD	E,(IY)		; E := PHYSICAL UNIT
-	LD	C,$00		; C := DEVICE TYPE, 0x00 IS RS-232
-	XOR	A		; SIGNAL SUCCESS
+	LD	D,CIODEV_DUART		; D := DEVICE TYPE
+	LD	E,(IY)			; E := PHYSICAL UNIT
+	LD	C,$00			; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,(IY+3)		; L := BASE I/O ADDRESS
+	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
 ; DUART DETECTION ROUTINE
diff --git a/Source/HBIOS/pio.asm b/Source/HBIOS/pio.asm
index 349858a2..c0d230f7 100644
--- a/Source/HBIOS/pio.asm
+++ b/Source/HBIOS/pio.asm
@@ -720,6 +720,8 @@ PPI_DEVICE:
 	LD	D,CIODEV_PIO		; D := DEVICE TYPE
 	LD	E,(IY)			; E := PHYSICAL UNIT
 	LD	C,$40			; C := ATTRIBUTE
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,(IY+3)		; L := BASE I/O ADDRESS
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
diff --git a/Source/HBIOS/ppp.asm b/Source/HBIOS/ppp.asm
index e564db7d..bad672cf 100644
--- a/Source/HBIOS/ppp.asm
+++ b/Source/HBIOS/ppp.asm
@@ -357,6 +357,8 @@ PPPCON_DEVICE:
 	LD	D,CIODEV_PPPCON		; D := DEVICE TYPE
 	LD	E,0			; E := DEVICE NUM, ALWAYS 0
 	LD	C,$BF			; C := DEVICE TYPE, 0xBF IS PROP TERM
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,PPIBASE		; L := BASE I/O ADDRESS
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
diff --git a/Source/HBIOS/prp.asm b/Source/HBIOS/prp.asm
index 3ed73f09..9a62a741 100644
--- a/Source/HBIOS/prp.asm
+++ b/Source/HBIOS/prp.asm
@@ -230,6 +230,8 @@ PRPCON_DEVICE:
 	LD	D,CIODEV_PRPCON		; D := DEVICE TYPE
 	LD	E,0			; E := DEVICE NUM, ALWAYS 0
 	LD	C,$BF			; C := DEVICE TYPE, 0xBF IS PROP TERM
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,PRP_IOBASE		; L := BASE I/O ADDRESS
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
diff --git a/Source/HBIOS/sio.asm b/Source/HBIOS/sio.asm
index 9d7fc13a..9debbc45 100644
--- a/Source/HBIOS/sio.asm
+++ b/Source/HBIOS/sio.asm
@@ -949,6 +949,8 @@ SIO_DEVICE:
 	LD	D,CIODEV_SIO		; D := DEVICE TYPE
 	LD	E,(IY)			; E := PHYSICAL UNIT
 	LD	C,$00			; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,(IY+14)		; H := MODE
+	LD	L,(IY+3)		; L := BASE I/O ADDRESS
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
@@ -1147,6 +1149,7 @@ SIO0A_CFG:
 	.DW	SIO0ACLK & $FFFF	; CLOCK FREQ AS
 	.DW	SIO0ACLK >> 16		; ... DWORD VALUE
 	.DB	SIO0ACTCC		; CTC CHANNEL
+	.DB	SIO0MODE		; MODE
 ;
 SIO_CFGSIZ	.EQU	$ - SIO_CFG	; SIZE OF ONE CFG TABLE ENTRY
 ;
@@ -1162,6 +1165,7 @@ SIO0B_CFG:
 	.DW	SIO0BCLK & $FFFF	; CLOCK FREQ AS
 	.DW	SIO0BCLK >> 16		; ... DWORD VALUE
 	.DB	SIO0BCTCC		; CTC CHANNEL
+	.DB	SIO0MODE		; MODE
 ;
 #IF (SIOCNT >= 2)
 ;
@@ -1177,6 +1181,7 @@ SIO1A_CFG:
 	.DW	SIO1ACLK & $FFFF	; CLOCK FREQ AS
 	.DW	SIO1ACLK >> 16		; ... DWORD VALUE
 	.DB	SIO1ACTCC		; CTC CHANNEL
+	.DB	SIO1MODE		; MODE
 ;
 	; SIO1 CHANNEL B
 SIO1B_CFG:
@@ -1190,6 +1195,7 @@ SIO1B_CFG:
 	.DW	SIO1BCLK & $FFFF	; CLOCK FREQ AS
 	.DW	SIO1BCLK >> 16		; ... DWORD VALUE
 	.DB	SIO1BCTCC		; CTC CHANNEL
+	.DB	SIO1MODE		; MODE
 ;
 #ENDIF
 ;
diff --git a/Source/HBIOS/uart.asm b/Source/HBIOS/uart.asm
index af00cebe..52ecd2cf 100644
--- a/Source/HBIOS/uart.asm
+++ b/Source/HBIOS/uart.asm
@@ -339,6 +339,8 @@ UART_DEVICE:
 	LD	D,CIODEV_UART	; D := DEVICE TYPE
 	LD	E,(IY)		; E := PHYSICAL UNIT
 	LD	C,$00		; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,0		; H := 0, DRIVER HAS NO MODES
+	LD	L,(IY+2)	; L := BASE I/O ADDRESS
 	XOR	A		; SIGNAL SUCCESS
 	RET
 ;
diff --git a/Source/HBIOS/uf.asm b/Source/HBIOS/uf.asm
index efc3d9b3..b67c15ab 100644
--- a/Source/HBIOS/uf.asm
+++ b/Source/HBIOS/uf.asm
@@ -154,6 +154,8 @@ UF_DEVICE:
 	XOR	A			; SIGNAL SUCCESS
 	LD	E,A			; E := PHYSICAL UNIT, ALWAYS 0
 	LD	C,A			; C := DEVICE TYPE, 0x00 IS RS-232
+	LD	H,0			; H := 0, DRIVER HAS NO MODES
+	LD	L,UFBASE		; L := BASE I/O ADDRESS
 	RET
 ;
 ; USB-FIFO DETECTION ROUTINE
diff --git a/Source/ver.inc b/Source/ver.inc
index ff8f4c70..53106fe9 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.16"
+#DEFINE BIOSVER	"3.1.1-pre.17"
diff --git a/Source/ver.lib b/Source/ver.lib
index 14fd4afe..b2bb943d 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.16"
+	db	"3.1.1-pre.17"
 	endm