diff --git a/Doc/RomWBW Applications.pdf b/Doc/RomWBW Applications.pdf
index bceb29e6..37a2f479 100644
Binary files a/Doc/RomWBW Applications.pdf and b/Doc/RomWBW Applications.pdf differ
diff --git a/Doc/RomWBW Disk Catalog.pdf b/Doc/RomWBW Disk Catalog.pdf
index 58790083..3b865a96 100644
Binary files a/Doc/RomWBW Disk Catalog.pdf and b/Doc/RomWBW Disk Catalog.pdf differ
diff --git a/Doc/RomWBW Errata.pdf b/Doc/RomWBW Errata.pdf
index fddb16bf..83d4bd30 100644
Binary files a/Doc/RomWBW Errata.pdf and b/Doc/RomWBW Errata.pdf differ
diff --git a/Doc/RomWBW ROM Applications.pdf b/Doc/RomWBW ROM Applications.pdf
index 95eb34f0..9adf63f5 100644
Binary files a/Doc/RomWBW ROM Applications.pdf and b/Doc/RomWBW ROM Applications.pdf differ
diff --git a/Doc/RomWBW System Guide.pdf b/Doc/RomWBW System Guide.pdf
index e9dc86a1..d73ee245 100644
Binary files a/Doc/RomWBW System Guide.pdf and b/Doc/RomWBW System Guide.pdf differ
diff --git a/Doc/RomWBW User Guide.pdf b/Doc/RomWBW User Guide.pdf
index 1cae6c7e..ba29e729 100644
Binary files a/Doc/RomWBW User Guide.pdf and b/Doc/RomWBW User Guide.pdf differ
diff --git a/ReadMe.md b/ReadMe.md
index 03041195..9632a487 100644
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -3,7 +3,7 @@
 **RomWBW ReadMe** \
 Version 3.1 Pre-release \
 Wayne Warthen  ([wwarthen@gmail.com](mailto:wwarthen@gmail.com)) \
-13 Feb 2023
+16 Feb 2023
 
 # Overview
 
diff --git a/ReadMe.txt b/ReadMe.txt
index 27a9166f..16082214 100644
--- a/ReadMe.txt
+++ b/ReadMe.txt
@@ -1,6 +1,6 @@
 RomWBW ReadMe
 Wayne Warthen (wwarthen@gmail.com)
-13 Feb 2023
+16 Feb 2023
 
 
 
diff --git a/Source/Apps/Survey/survey.mac b/Source/Apps/Survey/survey.mac
index e26a9f77..23b2fb9f 100644
--- a/Source/Apps/Survey/survey.mac
+++ b/Source/Apps/Survey/survey.mac
@@ -641,27 +641,41 @@ PORTLP:
 	jr	nz,rd180
 ;
 	; Z80 port read
+	; Read port using IN A,(C), push result
 	ld	a,d
 	ld	c,a
-	ld	(pnum),a		; dynamic update
+	ld	(pnum0a),a		; dynamic update
+	ld	(pnum0b),a		; dynamic update
+	ld	b,0
 	in	a,(c)
 	push	af
-	ld	b,0
-	in	a,(0FFH)
-pnum	equ	$-1
+	; Read port using IN A,(port), push result
+	in	a,(0ffh)		; IN0
+pnum0a	equ	$-1
+	push	af
+	; Read port using IN A,(port), push result
+	in	a,(0ffh)		; IN0
+pnum0b	equ	$-1
 	push	af
 	jr	rdz
 ;
 rd180:
 	; Z180 port read
+	; Read port using IN A,(C), push result
 	ld	a,d
 	ld	c,a
-	ld	(pnum1),a		; dynamic update
+	ld	(pnum1a),a		; dynamic update
+	ld	(pnum1b),a		; dynamic update
+	ld	b,0
 	in	a,(c)
 	push	af
-	ld	b,0
+	; Read port using IN0 A,(port), push result
 	db	0EDH,038H,0FFH		; IN0
-pnum1	equ	$-1
+pnum1a	equ	$-1
+	push	af
+	; Read port using IN0 A,(port), push result
+	db	0EDH,038H,0FFH		; IN0
+pnum1b	equ	$-1
 	push	af
 ;
 rdz:
@@ -674,15 +688,20 @@ rdz:
 	ei				; interrupts back on now
 ;
 ; port is considered inactive if values read from different port
-; read mechanisms differ or if the value $FF is read consistently
-;
-	pop	af
-	ld	c,a
-	pop	af
-	cp	c
-	jr	nz,NEXTPT
-	cp	0FFH
-	jr	z,NEXTPT
+; read mechanisms differ or if the value $FF is read consistently,
+; or if the value read is equal to the port number itself
+;
+	pop	bc			; second IN0 (port) value
+	pop	af			; first IN0 (port) valule
+	cp	b			; same?
+	pop	bc			; IN (C) value
+	jr	nz,ISPORT		; if no, active running ctr port
+	cp	b			; same?
+	jr	nz,NEXTPT		; if not, inactive port
+	cp	0FFh			; pullup value???
+	jr	z,NEXTPT		; if so, consider not active
+	cp	d			; value same as port num???
+	jr	z,NEXTPT		; if so, consider not active
 ;
 	.8080
 ISPORT:
diff --git a/Source/Apps/Test/Build.cmd b/Source/Apps/Test/Build.cmd
index dea44672..f757cf32 100644
--- a/Source/Apps/Test/Build.cmd
+++ b/Source/Apps/Test/Build.cmd
@@ -23,7 +23,7 @@ pushd ps2info && call Build || exit /b & popd
 pushd 2piotst && call Build || exit /b & popd
 pushd piomon && call Build || exit /b & popd
 pushd banktest && call Build || exit /b & popd
-pushd portswp && call Build || exit /b & popd
+pushd portscan && call Build || exit /b & popd
 
 goto :eof
 
diff --git a/Source/Apps/Test/Clean.cmd b/Source/Apps/Test/Clean.cmd
index f611848e..1e62b7d8 100644
--- a/Source/Apps/Test/Clean.cmd
+++ b/Source/Apps/Test/Clean.cmd
@@ -20,4 +20,4 @@ pushd ps2info && call Clean || exit /b 1 & popd
 pushd 2piotst && call Clean || exit /b 1 & popd
 pushd piomon && call Clean || exit /b 1 & popd
 pushd banktest && call Clean || exit /b 1 & popd
-pushd portswp && call Clean || exit /b 1 & popd
+pushd portscan && call Clean || exit /b 1 & popd
diff --git a/Source/Apps/Test/Makefile b/Source/Apps/Test/Makefile
index e1f78754..6fbce342 100644
--- a/Source/Apps/Test/Makefile
+++ b/Source/Apps/Test/Makefile
@@ -1,5 +1,5 @@
 OBJECTS = 
-SUBDIRS = DMAmon I2C inttest ppidetst ramtest tstdskng rzsz vdctest kbdtest ps2info 2piotst piomon banktest portswp
+SUBDIRS = DMAmon I2C inttest ppidetst ramtest tstdskng rzsz vdctest kbdtest ps2info 2piotst piomon banktest portscan
 DEST = ../../../Binary/Apps/Test
 TOOLS =../../../Tools
 
diff --git a/Source/Apps/Test/portscan/Build.cmd b/Source/Apps/Test/portscan/Build.cmd
new file mode 100644
index 00000000..38027da2
--- /dev/null
+++ b/Source/Apps/Test/portscan/Build.cmd
@@ -0,0 +1,11 @@
+@echo off
+setlocal
+
+set TOOLS=../../../../Tools
+set PATH=%TOOLS%\tasm32;%PATH%
+set TASMTABS=%TOOLS%\tasm32
+
+tasm -t180 -g3 -fFF portscan.asm portscan.com portscan.lst || exit /b
+
+copy /Y portscan.com ..\..\..\..\Binary\Apps\Test\ || exit /b
+
diff --git a/Source/Apps/Test/portswp/Clean.cmd b/Source/Apps/Test/portscan/Clean.cmd
similarity index 100%
rename from Source/Apps/Test/portswp/Clean.cmd
rename to Source/Apps/Test/portscan/Clean.cmd
diff --git a/Source/Apps/Test/portswp/Makefile b/Source/Apps/Test/portscan/Makefile
similarity index 81%
rename from Source/Apps/Test/portswp/Makefile
rename to Source/Apps/Test/portscan/Makefile
index 81d334fc..b1e9ee84 100644
--- a/Source/Apps/Test/portswp/Makefile
+++ b/Source/Apps/Test/portscan/Makefile
@@ -1,4 +1,4 @@
-OBJECTS = portswp.com
+OBJECTS = portscan.com
 DEST = ../../../../Binary/Apps/Test
 TOOLS =../../../../Tools
 
diff --git a/Source/Apps/Test/portswp/portswp.asm b/Source/Apps/Test/portscan/portscan.asm
similarity index 90%
rename from Source/Apps/Test/portswp/portswp.asm
rename to Source/Apps/Test/portscan/portscan.asm
index dd6d49c2..47a73b5c 100644
--- a/Source/Apps/Test/portswp/portswp.asm
+++ b/Source/Apps/Test/portscan/portscan.asm
@@ -1,5 +1,5 @@
 ;===============================================================================
-; PORTSWP - Sweep Ports
+; PORTSCAN - Sweep Ports
 ;
 ;===============================================================================
 ;
@@ -7,7 +7,7 @@
 ;_______________________________________________________________________________
 ;
 ; Usage:
-;   PORTSWP
+;   PORTSCAN
 ;
 ; Operation:
 ;   Reads all ports (multiple ways) and displays values read
@@ -104,10 +104,22 @@ process:
 	mlt	de		; de = 30 if z180
 	ld	a,e		; result to A
 	cp	30		; check if multiply happened
-	jr	nz,loop		; if invalid, then Z80
+	jr	nz,prtcpu		; if invalid, then Z80
 	or	$FF		; flag value for Z180
 	ld	(is180),a	; save it
 ;
+prtcpu:
+	ld	de,msgcpu
+	call	prtstr
+	ld	a,(is180)
+	or	a
+	ld	de,msgz80
+	jr	z,prtcpu1
+	ld	de,msgz180
+prtcpu1:
+	call	prtstr
+	call	crlf
+;
 loop:
 	call	crlf
 	ld	a,(curport)
@@ -149,7 +161,6 @@ done:
 	call	crlf2
 	ld	de,msgdone	; message to print
 	call	prtstr		; do it
-;
 	ret			; all done
 ;
 ;
@@ -159,33 +170,28 @@ portread:
 	or	a
 	jr	nz,portread_z180
 ;
-portread_z80:	; user traditional "IN"
+portread_z80:	; use traditional "IN"
 	; read port using IN <portnum>
 	ld	a,(curport)	; get current port
-	ld	(port),a	; modify IN instruction
+	ld	(pnum0),a	; modify IN instruction
+	nop			; defeat Z280 pipeline
+	nop
 	in	a,($FF)		; read the port
-port	.equ	$-1
+pnum0	.equ	$-1
 	ld	(hl),a		; save it
 	inc	hl		; bump value list pointer
-;
-	; read port using IN (C)
-	ld	a,(curport)	; get current port
-	ld	b,0		; in case 16 bits decoded
-	ld	c,a		; move to reg C
-	in	a,(c)		; read the port
-	ld	(hl),a		; save it
-	inc	hl		; bump value list pointer
-	ret
+	jr	portread1
 ;
 portread_z180:	; use "IN0"
 	; read port using IN <portnum>
 	ld	a,(curport)	; get current port
-	ld	(port1),a	; modify IN instruction
+	ld	(pnum1),a	; modify IN instruction
 	in0	a,($FF)		; read the port
-port1	.equ	$-1
+pnum1	.equ	$-1
 	ld	(hl),a		; save it
 	inc	hl		; bump value list pointer
 ;
+portread1:
 	; read port using IN (C)
 	ld	a,(curport)	; get current port
 	ld	b,0		; in case 16 bits decoded
@@ -575,18 +581,19 @@ stack	.equ	$		; stack top
 ;
 ; Messages
 ;
-msgban	.db	"PORTSWP v1.0, 14-Feb-2023",13,10
+msgban	.db	"PORTSCAN v1.0, 16-Feb-2023",13,10
 	.db	"Copyright (C) 2023, Wayne Warthen, GNU GPL v3",0
-msguse	.db	"Usage: PORTSWP",13,10
-msgprm	.db	"Parameter error (PORTSWP /? for usage)",0
+msguse	.db	"Usage: PORTSCAN",13,10
+msgprm	.db	"Parameter error (PORTSCAN /? for usage)",0
 msgbio	.db	"Incompatible BIOS or version, "
 	.db	"HBIOS v", '0' + rmj, ".", '0' + rmn, " required",0
 str_sep	.db	": ",0
 ;
-;msgcur	.db	"Initial Bank ID = 0x",0
-;msg80	.db	"Hello from bank 0x80!",0
-;msgxcal	.db	"Inter-bank procedure call test...",0
+msgcpu	.db	"CPU is ",0
+msgz80	.db	"Z80",0
+msgz180	.db	"Z180",0
 msgdone	.db	"End of Port Sweep",0
+
 ;
 ;
 ;
diff --git a/Source/Apps/Test/portswp/Build.cmd b/Source/Apps/Test/portswp/Build.cmd
deleted file mode 100644
index 763cf712..00000000
--- a/Source/Apps/Test/portswp/Build.cmd
+++ /dev/null
@@ -1,11 +0,0 @@
-@echo off
-setlocal
-
-set TOOLS=../../../../Tools
-set PATH=%TOOLS%\tasm32;%PATH%
-set TASMTABS=%TOOLS%\tasm32
-
-tasm -t180 -g3 -fFF portswp.asm portswp.com portswp.lst || exit /b
-
-copy /Y portswp.com ..\..\..\..\Binary\Apps\Test\ || exit /b
-
diff --git a/Source/Doc/UserGuide.md b/Source/Doc/UserGuide.md
index 1d7cdfa1..601efe1d 100644
--- a/Source/Doc/UserGuide.md
+++ b/Source/Doc/UserGuide.md
@@ -3159,8 +3159,10 @@ the RomWBW HBIOS configuration.
 |-------------------|---------------|
 | ROM Image File    | SBC_std.rom   |
 | Console Baud Rate | 38400         |
+| Interrupts        | None          |
 
  - CPU speed is detected at startup if DS1302 RTC is active
+   - Otherwise 8.000 MHz assumed
  - Hardware auto-detected:
    - Onboard DS1302 RTC
    - Onboard UART Serial Adapter
@@ -3171,9 +3173,9 @@ the RomWBW HBIOS configuration.
    - DiskIO V3 Floppy Disk Controller w/ 3.5" HD Drives
    - PropIO Video, Keyboard, & SD Card
  - SBC V1 has a known race condition in the bank switching
-   circuit which is likely to cause system instability.  SBC
-   V2 does not have this issue.
- 
+   circuit which is likely to cause system instability.  SBC V2
+   does not have this issue.
+
 `\clearpage`{=latex}
 
 ### RetroBrew Z80 SimH
@@ -3182,7 +3184,9 @@ the RomWBW HBIOS configuration.
 |-------------------|---------------|
 | ROM Image File    | SBC_simh.rom  |
 | Console Baud Rate | 38400         |
+| Interrupts        | Mode 1        |
 
+ - System timer is generated by SimH
  - Hardware auto-detected:
    - SimH emulated 8250 Serial Adapter
    - SimH emulated hard disk drives
@@ -3196,8 +3200,10 @@ the RomWBW HBIOS configuration.
 |-------------------|---------------|
 | ROM Image File    | ZETA_std.rom  |
 | Console Baud Rate | 38400         |
+| Interrupts        | None          |
 
  - CPU speed is detected at startup if DS1302 RTC is active
+   - Otherwise 20.000 MHz assumed
  - Hardware auto-detected:
    - Onboard DS1302 RTC
    - Onboard UART Serial Adapter
@@ -3218,6 +3224,7 @@ the RomWBW HBIOS configuration.
 | Console Baud Rate | 38400         |
 
  - CPU speed is detected at startup if DS1302 RTC is active
+   - Otherwise 20.000 MHz assumed
  - System timer is generated by onboard CTC
  - Hardware auto-detected:
    - Onboard DS1302 RTC
@@ -3240,8 +3247,10 @@ the RomWBW HBIOS configuration.
 | Console Baud Rate | 38400         |
 
  - CPU speed is detected at startup if DS1302 RTC is active
+   - Otherwise 18.432 MHz assumed
  - System timer is generated by Z180 CPU
  - Hardware auto-detected:
+   - Onboard DS1302 RTC
    - Onboard Z180 ASCI Serial Ports
    - Onboard Floppy Disk Controller w/ 3.5" HD Drives
    - Onboard TMS9918 Video Controller
@@ -3257,18 +3266,22 @@ the RomWBW HBIOS configuration.
 |-------------------|---------------|
 | ROM Image File    | MK4_std.rom   |
 | Console Baud Rate | 38400         |
+| Interrupts        | Mode 2        |
 
  - CPU speed is detected at startup if DS1302 RTC is active
+   - Otherwise 18.432 MHz assumed
  - System timer is generated by Z180 CPU
  - Hardware auto-detected:
+   - Onboard DS1302 RTC
    - Onboard Z180 ASCI Serial Ports
+   - UART Serial Interfaces (CAS, MFP, UART4)
+   - CVDU Display Adapter
+   - VGA3 Display Adapter
    - Onboard SD Card Interface via CSIO
    - Onboard IDE CF Card Interface
    - DIDE Floppy Disk Controller w/ 3.5" HD Drives
    - DIDE IDE Hard Disk Controller
    - PropIO Video, Keyboard, & SD Card
-   - CVDU Display Adapter
-   - VGA3 Display Adapter
 
 `\clearpage`{=latex}
 
diff --git a/Source/HBIOS/Config/MK4_std.asm b/Source/HBIOS/Config/MK4_std.asm
index 43ac3748..6f840f2d 100644
--- a/Source/HBIOS/Config/MK4_std.asm
+++ b/Source/HBIOS/Config/MK4_std.asm
@@ -26,23 +26,31 @@
 ;
 #include "cfg_mk4.asm"
 ;
+CPUOSC		.SET	18432000	; CPU OSC FREQ IN MHZ
+INTMODE		.SET	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
+CRTACT		.SET	TRUE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+;
 Z180_CLKDIV	.SET	1		; Z180: CHK DIV: 0=OSC/2, 1=OSC, 2=OSC*2
 Z180_MEMWAIT	.SET	0		; Z180: MEMORY WAIT STATES (0-3)
 Z180_IOWAIT	.SET	1		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
 ;
-CRTACT		.SET	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+UARTCAS		.SET	TRUE		; UART: AUTO-DETECT ECB CASSETTE UART
+UARTMFP		.SET	TRUE		; UART: AUTO-DETECT MF/PIC UART
+UART4		.SET	TRUE		; UART: AUTO-DETECT 4UART UART
+SIOENABLE	.SET	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
 ;
+TMSENABLE	.SET	FALSE		; TMS: ENABLE TMS9918 VIDEO/KBD DRIVER (TMS.ASM)
 VDUENABLE	.SET	FALSE		; VDU: ENABLE VDU VIDEO/KBD DRIVER (VDU.ASM)
 CVDUENABLE	.SET	TRUE		; CVDU: ENABLE CVDU VIDEO/KBD DRIVER (CVDU.ASM)
 VGAENABLE	.SET	TRUE		; VGA: ENABLE VGA VIDEO/KBD DRIVER (VGA.ASM)
+VDAEMU_SERKBD	.SET	0		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
 ;
 FDENABLE	.SET	TRUE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
 FDMODE		.SET	FDMODE_DIDE	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|DIDE|N8|DIO3|RCSMC|RCWDC|DYNO|EPWDC]
 ;
 IDEENABLE	.SET	TRUE		; IDE: ENABLE IDE DISK DRIVER (IDE.ASM)
-;
 PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
-;
 SDENABLE	.SET	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
 SDMODE		.SET	SDMODE_MK4	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC]
 ;
diff --git a/Source/HBIOS/Config/N8_std.asm b/Source/HBIOS/Config/N8_std.asm
index 919167ea..03cf7421 100644
--- a/Source/HBIOS/Config/N8_std.asm
+++ b/Source/HBIOS/Config/N8_std.asm
@@ -26,12 +26,19 @@
 ;
 #include "cfg_n8.asm"
 ;
+CPUOSC		.SET	18432000	; CPU OSC FREQ IN MHZ
+INTMODE		.SET	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
+CRTACT		.SET	TRUE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+;
 Z180_CLKDIV	.SET	1		; Z180: CHK DIV: 0=OSC/2, 1=OSC, 2=OSC*2
 Z180_MEMWAIT	.SET	0		; Z180: MEMORY WAIT STATES (0-3)
 Z180_IOWAIT	.SET	1		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
 ;
-CRTACT		.SET	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
+TMSENABLE	.SET	TRUE		; TMS: ENABLE TMS9918 VIDEO/KBD DRIVER (TMS.ASM)
 ;
-AY38910ENABLE	.SET	TRUE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
+FDENABLE	.SET	TRUE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
 ;
+PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
 SDMODE		.SET	SDMODE_CSIO	; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
+;
+AY38910ENABLE	.SET	TRUE		; AY: AY-3-8910 / YM2149 SOUND DRIVER
diff --git a/Source/HBIOS/Config/SBC_simh.asm b/Source/HBIOS/Config/SBC_simh.asm
index 6a45eb91..2ee17a8b 100644
--- a/Source/HBIOS/Config/SBC_simh.asm
+++ b/Source/HBIOS/Config/SBC_simh.asm
@@ -30,9 +30,7 @@ INTMODE		.SET	1		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
 ;
 HTIMENABLE	.SET	TRUE		; ENABLE SIMH TIMER SUPPORT
 ;
-SIMRTCENABLE	.SET	TRUE		; ENABLE SIMH CLOCK DRIVER (SIMRTC.ASM)
-DSRTCENABLE	.SET	FALSE		; DSRTC: ENABLE DS-1302 CLOCK DRIVER (DSRTC.ASM)
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+UARTSBCFORCE	.SET	TRUE		; UART: FORCE DETECTION OF SBC UART (FOR SIMH)
 ;
 HDSKENABLE	.SET	TRUE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
-;
-UARTSBCFORCE	.SET	TRUE		; UART: FORCE DETECTION OF SBC UART (FOR SIMH)
diff --git a/Source/HBIOS/Config/SBC_std.asm b/Source/HBIOS/Config/SBC_std.asm
index 6189daea..ce0f07c3 100644
--- a/Source/HBIOS/Config/SBC_std.asm
+++ b/Source/HBIOS/Config/SBC_std.asm
@@ -26,19 +26,29 @@
 ;
 #include "cfg_sbc.asm"
 ;
+CPUOSC		.SET	8000000		; CPU OSC FREQ IN MHZ
+INTMODE		.SET	0		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
 CRTACT		.SET	TRUE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 ;
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+UARTSBC		.SET	TRUE		; UART: AUTO-DETECT SBC/ZETA ONBOARD UART
+UARTCAS		.SET	TRUE		; UART: AUTO-DETECT ECB CASSETTE UART
+UARTMFP		.SET	TRUE		; UART: AUTO-DETECT MF/PIC UART
+UART4		.SET	TRUE		; UART: AUTO-DETECT 4UART UART
+UARTRC		.SET	FALSE		; UART: AUTO-DETECT RC UART
+SIOENABLE	.SET	TRUE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+;
+TMSENABLE	.SET	FALSE		; TMS: ENABLE TMS9918 VIDEO/KBD DRIVER (TMS.ASM)
 VDUENABLE	.SET	FALSE		; VDU: ENABLE VDU VIDEO/KBD DRIVER (VDU.ASM)
 CVDUENABLE	.SET	TRUE		; CVDU: ENABLE CVDU VIDEO/KBD DRIVER (CVDU.ASM)
 VGAENABLE	.SET	TRUE		; VGA: ENABLE VGA VIDEO/KBD DRIVER (VGA.ASM)
+VDAEMU_SERKBD	.SET	0		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
 ;
 FDENABLE	.SET	TRUE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
 FDMODE		.SET	FDMODE_DIO3	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|DIDE|N8|DIO3|RCSMC|RCWDC|DYNO|EPWDC]
 ;
 IDEENABLE	.SET	FALSE		; IDE: ENABLE IDE DISK DRIVER (IDE.ASM)
-;
 PPIDEENABLE	.SET	TRUE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
-;
 SDENABLE	.SET	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
 SDMODE		.SET	SDMODE_PPI	; SD: DRIVER MODE: SDMODE_[JUHA|N8|CSIO|PPI|UART|DSD|MK4|SC]
 ;
diff --git a/Source/HBIOS/Config/ZETA2_std.asm b/Source/HBIOS/Config/ZETA2_std.asm
index 9fd7c993..5c6673c3 100644
--- a/Source/HBIOS/Config/ZETA2_std.asm
+++ b/Source/HBIOS/Config/ZETA2_std.asm
@@ -26,12 +26,18 @@
 ;
 #include "cfg_zeta2.asm"
 ;
-;UARTCFG		.SET	UARTCFG | SER_RTS
-;
+CPUOSC		.SET	20000000	; CPU OSC FREQ IN MHZ
+INTMODE		.SET	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
 CRTACT		.SET	TRUE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 ;
-PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+;UARTCFG	.SET	UARTCFG | SER_RTS
+UARTSBC		.SET	TRUE		; UART: AUTO-DETECT SBC/ZETA ONBOARD UART
 ;
+FDENABLE	.SET	TRUE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
+FDMODE		.SET	FDMODE_ZETA	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|DIDE|N8|DIO3|RCSMC|RCWDC|DYNO|EPWDC]
+;
+PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
 SDENABLE	.SET	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
 ;
 PPPENABLE	.SET	TRUE		; PPP: ENABLE ZETA PARALLEL PORT PROPELLER BOARD DRIVER (PPP.ASM)
diff --git a/Source/HBIOS/Config/ZETA_std.asm b/Source/HBIOS/Config/ZETA_std.asm
index 06ae8cbe..2b44c968 100644
--- a/Source/HBIOS/Config/ZETA_std.asm
+++ b/Source/HBIOS/Config/ZETA_std.asm
@@ -26,10 +26,18 @@
 ;
 #include "cfg_zeta.asm"
 ;
+CPUOSC		.SET	20000000	; CPU OSC FREQ IN MHZ
+INTMODE		.SET	0		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2
 CRTACT		.SET	TRUE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 ;
-PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
+UARTENABLE	.SET	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
+;UARTCFG	.SET	UARTCFG | SER_RTS
+UARTSBC		.SET	TRUE		; UART: AUTO-DETECT SBC/ZETA ONBOARD UART
+;
+FDENABLE	.SET	TRUE		; FD: ENABLE FLOPPY DISK DRIVER (FD.ASM)
+FDMODE		.SET	FDMODE_ZETA	; FD: DRIVER MODE: FDMODE_[DIO|ZETA|ZETA2|DIDE|N8|DIO3|RCSMC|RCWDC|DYNO|EPWDC]
 ;
+PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM)
 SDENABLE	.SET	FALSE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
 ;
 PPPENABLE	.SET	TRUE		; PPP: ENABLE ZETA PARALLEL PORT PROPELLER BOARD DRIVER (PPP.ASM)
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index b2692239..691b74f0 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -140,6 +140,17 @@ Z2UENABLE	.EQU	FALSE		; Z2U: ENABLE Z280 UART SERIAL DRIVER (Z2U.ASM)
 ACIAENABLE	.EQU	FALSE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
 ;
 SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
+SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
+SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
+SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
+SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+SIO0BCLK	.EQU	(4915200/8)	; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
+SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 ;
 XIOCFG		.EQU	DEFSERCFG	; XIO: SERIAL LINE CONFIG
 ;
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index f8b34a4c..cb0f75a5 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -142,6 +142,17 @@ Z2UENABLE	.EQU	FALSE		; Z2U: ENABLE Z280 UART SERIAL DRIVER (Z2U.ASM)
 ACIAENABLE	.EQU	FALSE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
 ;
 SIOENABLE	.EQU	FALSE		; SIO: ENABLE ZILOG SIO SERIAL DRIVER (SIO.ASM)
+SIODEBUG	.EQU	FALSE		; SIO: ENABLE DEBUG OUTPUT
+SIOBOOT		.EQU	0		; SIO: REBOOT ON RCV CHAR (0=DISABLED)
+SIOCNT		.EQU	1		; SIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
+SIO0MODE	.EQU	SIOMODE_ZP	; SIO 0: CHIP TYPE: SIOMODE_[STD|RC|SMB|ZP]
+SIO0BASE	.EQU	$B0		; SIO 0: REGISTERS BASE ADR
+SIO0ACLK	.EQU	(4915200/8)	; SIO 0A: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0ACFG	.EQU	DEFSERCFG	; SIO 0A: SERIAL LINE CONFIG
+SIO0ACTCC	.EQU	-1		; SIO 0A: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
+SIO0BCLK	.EQU	(4915200/8)	; SIO 0B: OSC FREQ IN HZ, ZP=2457600/4915200, RC/SMB=7372800
+SIO0BCFG	.EQU	DEFSERCFG	; SIO 0B: SERIAL LINE CONFIG
+SIO0BCTCC	.EQU	-1		; SIO 0B: CTC CHANNEL 0=A, 1=B, 2=C, 3=D, -1 FOR NONE
 ;
 XIOCFG		.EQU	DEFSERCFG	; XIO: SERIAL LINE CONFIG
 ;
diff --git a/Source/HBIOS/dbgmon.asm b/Source/HBIOS/dbgmon.asm
index d8792bc3..a2a0ceac 100644
--- a/Source/HBIOS/dbgmon.asm
+++ b/Source/HBIOS/dbgmon.asm
@@ -40,8 +40,6 @@ ENA_XM	.EQU	TRUE			; INCLUDE XMODEM IF SPACE AVAILABLE
 ;
 ENA_MBC6502	.EQU	FALSE		; ENABLE OR DISABLE MBC6502 OPTION
 ;
-#INCLUDE "util.asm"
-;
 ;__UART_ENTRY_________________________________________________________________
 ;
 ;	SERIAL MONITOR STARTUP
@@ -1846,6 +1844,233 @@ DSKY_ENTRY:
 ;
 #ENDIF
 ;
+;==================================================================================================
+; UTILITY FUNCTIONS
+;==================================================================================================
+;
+;
+CHR_BEL		.EQU	07H
+CHR_CR		.EQU	0DH
+CHR_LF		.EQU	0AH
+CHR_BS		.EQU	08H
+CHR_ESC		.EQU	1BH
+;
+;__________________________________________________________________________________________________
+;
+; UTILITY PROCS TO PRINT SINGLE CHARACTERS WITHOUT TRASHING ANY REGISTERS
+;
+PC_SPACE:
+	PUSH	AF
+	LD	A,' '
+	JR	PC_PRTCHR
+PC_COLON:
+	PUSH	AF
+	LD	A,':'
+	JR	PC_PRTCHR
+PC_CR:
+	PUSH	AF
+	LD	A,CHR_CR
+	JR	PC_PRTCHR
+
+PC_LF:
+	PUSH	AF
+	LD	A,CHR_LF
+	JR	PC_PRTCHR
+
+PC_PRTCHR:
+	CALL	COUT
+	POP	AF
+	RET
+
+NEWLINE2:
+	CALL	NEWLINE
+NEWLINE:
+	CALL	PC_CR
+	CALL	PC_LF
+	RET
+PRTSTR:
+	LD	A,(HL)
+	INC	HL
+	CP	'$'
+	RET	Z
+	CALL	COUT
+	JR	PRTSTR
+;
+; PRINT THE HEX BYTE VALUE IN A
+;
+PRTHEXBYTE:
+	PUSH	AF
+	PUSH	DE
+	CALL	HEXASCII
+	LD	A,D
+	CALL	COUT
+	LD	A,E
+	CALL	COUT
+	POP	DE
+	POP	AF
+	RET
+;
+; CONVERT BINARY VALUE IN A TO ASCII HEX CHARACTERS IN DE
+;
+HEXASCII:
+	LD	D,A
+	CALL	HEXCONV
+	LD	E,A
+	LD	A,D
+	RLCA
+	RLCA
+	RLCA
+	RLCA
+	CALL	HEXCONV
+	LD	D,A
+	RET
+;
+; CONVERT LOW NIBBLE OF A TO ASCII HEX
+;
+HEXCONV:
+	AND	0FH	     ;LOW NIBBLE ONLY
+	ADD	A,90H
+	DAA
+	ADC	A,40H
+	DAA
+	RET
+;
+; ADD HL,A
+;
+;   A REGISTER IS DESTROYED!
+;
+ADDHLA:
+	ADD	A,L
+	LD	L,A
+	RET	NC
+	INC	H
+	RET
+;
+; DELAY 16US (CPU SPEED COMPENSATED) INCUDING CALL/RET INVOCATION
+; REGISTER A AND FLAGS DESTROYED
+; NO COMPENSATION FOR Z180 MEMORY WAIT STATES
+; THERE IS AN OVERHEAD OF 3TS PER INVOCATION
+;   IMPACT OF OVERHEAD DIMINISHES AS CPU SPEED INCREASES
+;
+; CPU SCALER (CPUSCL) = (CPUHMZ - 2) FOR 16US + 3TS DELAY
+;   NOTE: CPUSCL MUST BE >= 1!
+;
+; EXAMPLE: 8MHZ CPU (DELAY GOAL IS 16US)
+;   LOOP = ((6 * 16) - 5) = 91TS
+;   TOTAL COST = (91 + 40) = 131TS
+;   ACTUAL DELAY = (131 / 8) = 16.375US
+;
+	; --- TOTAL COST = (LOOP COST + 40) TS -----------------+
+DELAY:				; 17TS (FROM INVOKING CALL)	|
+	LD	A,(CPUSCL)	; 13TS				|
+;								|
+DELAY1:				;				|
+	; --- LOOP = ((CPUSCL * 16) - 5) TS ------------+	|
+	DEC	A		; 4TS			|	|
+  #IF (BIOS == BIOS_WBW)	;			|	|
+    #IF (CPUFAM == CPU_Z180)	;			|	|
+	OR	A		; +4TS FOR Z180		|	|
+    #ENDIF			;			|	|
+  #ENDIF			;			|	|
+	JR	NZ,DELAY1	; 12TS (NZ) / 7TS (Z)	|	|
+	; ----------------------------------------------+	|
+;								|
+	RET			; 10TS (RETURN)			|
+	;-------------------------------------------------------+
+;
+; DELAY 16US * DE (CPU SPEED COMPENSATED)
+; REGISTER DE, A, AND FLAGS DESTROYED
+; NO COMPENSATION FOR Z180 MEMORY WAIT STATES
+; THERE IS A 27TS OVERHEAD FOR CALL/RET PER INVOCATION
+;   IMPACT OF OVERHEAD DIMINISHES AS DE AND/OR CPU SPEED INCREASES
+;
+; CPU SCALER (CPUSCL) = (CPUHMZ - 2) FOR 16US OUTER LOOP COST
+;   NOTE: CPUSCL MUST BE > 0!
+;
+; EXAMPLE: 8MHZ CPU, DE=6250 (DELAY GOAL IS .1 SEC OR 100,000US)
+;   INNER LOOP = ((16 * 6) - 5) = 91TS
+;   OUTER LOOP = ((91 + 37) * 6250) = 800,000TS
+;   ACTUAL DELAY = ((800,000 + 27) / 8) = 100,003US
+;
+	; --- TOTAL COST = (OUTER LOOP + 27) TS ------------------------+
+VDELAY:				; 17TS (FROM INVOKING CALL)		|
+;									|
+	; --- OUTER LOOP = ((INNER LOOP + 37) * DE) TS ---------+	|
+	LD	A,(CPUSCL)	; 13TS				|	|
+;								|	|
+VDELAY1:			;				|	|
+	; --- INNER LOOP = ((CPUSCL * 16) - 5) TS ------+	|	|
+  #IF (BIOS == BIOS_WBW)	;			|	|	|
+    #IF (CPUFAM == CPU_Z180)	;			|	|	|
+	OR	A		; +4TS FOR Z180		|	|	|
+    #ENDIF			;			|	|	|
+  #ENDIF			;			|	|	|
+	DEC	A		; 4TS			|	|	|
+	JR	NZ,VDELAY1	; 12TS (NZ) / 7TS (Z)	|	|	|
+	; ----------------------------------------------+	|	|
+;								|	|
+	DEC	DE		; 6TS				|	|
+  #IF (BIOS == BIOS_WBW)	;			|	|	|
+    #IF (CPUFAM == CPU_Z180)	;				|	|
+	OR	A		; +4TS FOR Z180			|	|
+    #ENDIF			;				|	|
+  #ENDIF			;				|	|
+	LD	A,D		; 4TS				|	|
+	OR	E		; 4TS				|	|
+	JP	NZ,VDELAY	; 10TS				|	|
+	;-------------------------------------------------------+	|
+;									|
+	RET			; 10TS (FINAL RETURN)			|
+	;---------------------------------------------------------------+
+;
+; DELAY ABOUT 0.5 SECONDS
+; 500000US / 16US = 31250
+;
+LDELAY:
+	PUSH	AF
+	PUSH	DE
+	LD	DE,31250
+	CALL	VDELAY
+	POP	DE
+	POP	AF
+	RET
+;
+; INITIALIZE DELAY SCALER BASED ON OPERATING CPU SPEED
+; ENTER WITH A = CPU SPEED IN MHZ
+;
+DELAY_INIT:
+	CP	3			; TEST FOR <= 2 (SPECIAL HANDLING)
+	JR	C,DELAY_INIT1		; IF <= 2, SPECIAL PROCESSING
+	SUB	2			; ADJUST AS REQUIRED BY DELAY FUNCTIONS
+	JR	DELAY_INIT2		; AND CONTINUE
+DELAY_INIT1:
+	LD	A,1			; USE THE MIN VALUE OF 1
+DELAY_INIT2:
+	LD	(CPUSCL),A		; UPDATE CPU SCALER VALUE
+	RET
+
+  #IF (CPUMHZ < 3)
+CPUSCL	.DB	1			; CPU SCALER MUST BE > 0
+  #ELSE
+CPUSCL	.DB	CPUMHZ - 2		; OTHERWISE 2 LESS THAN PHI MHZ
+  #ENDIF
+;
+; SHORT DELAY FUNCTIONS.  NO CLOCK SPEED COMPENSATION, SO THEY
+; WILL RUN LONGER ON SLOWER SYSTEMS.  THE NUMBER INDICATES THE
+; NUMBER OF CALL/RET INVOCATIONS.  A SINGLE CALL/RET IS
+; 27 T-STATES ON A Z80, 25 T-STATES ON A Z180
+;
+;			; Z80	Z180
+;			; ----	----
+DLY64:	CALL	DLY32	; 1728	1600
+DLY32:	CALL	DLY16	; 864	800
+DLY16:	CALL	DLY8	; 432	400
+DLY8:	CALL	DLY4	; 216	200
+DLY4:	CALL	DLY2	; 108	100
+DLY2:	CALL	DLY1	; 54	50
+DLY1:	RET		; 27	25
+;
+;
 ;
 		.FILL	16,0		; SET MINIMUM STACK DEPTH
 SLACK		.EQU	(MON_END - $)
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index 03116f61..d17e3c9c 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -1020,6 +1020,9 @@ HB_ENTRYTBL	.EQU	$
 ;
 	JP	HB_START		; HBIOS INITIALIZATION
 	JP	HB_DISPATCH		; VECTOR TO DISPATCHER
+	JP	PRTSUM
+	; !!! DO NOT ADD ADDTIONAL VECTORS HERE WITHOUT
+	; CHECKING W/ WAYNE !!!
 ;
 HB_STKSIZ	.EQU	$100 - ($ & $FF)
 ;
diff --git a/Source/HBIOS/romldr.asm b/Source/HBIOS/romldr.asm
index 5e158dbd..2302e696 100644
--- a/Source/HBIOS/romldr.asm
+++ b/Source/HBIOS/romldr.asm
@@ -464,8 +464,6 @@ applst2:
 ; Device list
 ;
 devlst:
-	ld	hl,str_devlst		; device list header string
-	call	pstr			; display it
 	jp	prtall			; do it
 ;
 ; Set console interface unit
@@ -1814,99 +1812,26 @@ CST	.equ	cst
 ; Device inventory display
 ;=======================================================================
 ;
-; Print list of all drives (WBW)
-;
 #if (BIOS == BIOS_WBW)
 ;
-prtall:
-	call	nl			; formatting
-	ld	b,BF_SYSGET
-	ld	c,BF_SYSGET_DIOCNT
-	rst	08			; E := disk unit count
-	ld	b,e			; count to B
-	ld	a,b			; count to A
-	or	a			; set flags
-	ret	z			; bail out if zero
-	ld	c,0			; init device index
-;
-prtall1:
-	ld	hl,str_disk		; prefix string
-	call	pstr			; display it
-	ld	a,c			; index
-	call	prtdecb			; print it
-	ld	hl,str_on		; separator string
-	call	pstr
-	push	bc			; save loop control
-	ld	b,BF_DIODEVICE		; HBIOS func: report device info
-	rst	08			; call HBIOS
-	call	prtdrv			; print it
-	pop	bc			; restore loop control
-	inc	c			; bump index
-	djnz	prtall1			; loop as needed
-	ret				; done
-;
-; Print the device info
-; On input D has device type, E has device number
-; Destroy no registers other than A
+; Print list of all drives (WBW)
 ;
-prtdrv:
-	push	de			; preserve de
-	push	hl			; preserve HL
-	ld	a,d			; load device/unit
-	rrca				; rotate device
-	rrca				; ... bits
-	rrca				; ... into
-	rrca				; ... lowest 4 bits
-	and	$0F			; isolate device bits
-	add	a,a			; multiple by two for word table
-	ld	hl,devtbl		; point to start of table
-	call	addhla			; add A to HL for table entry
-	ld	a,(hl)			; deref HL for string adr
-	inc	hl			; ...
-	ld	h,(hl)			; ...
-	ld	l,a			; ...
-	call	pstr			; print the device nmemonic
-	pop	hl			; recover HL
-	pop	de			; recover DE
-	ld	a,e			; device number
-	call	prtdecb			; print it
-	ld	a,':'			; suffix
-	call	cout			; print it
-	ret
+; Just invoke the existing HBIOS routine...
 ;
-devtbl:	; device table
-	.dw	dev00, dev01, dev02, dev03
-	.dw	dev04, dev05, dev06, dev07
-	.dw	dev08, dev09, dev10, dev11
-	.dw	dev12, dev13, dev14, dev15
-;
-devunk	.db	"???",0
-dev00	.db	"MD",0
-dev01	.db	"FD",0
-dev02	.db	"RAMF",0
-dev03	.db	"IDE",0
-dev04	.db	"ATAPI",0
-dev05	.db	"PPIDE",0
-dev06	.db	"SD",0
-dev07	.db	"PRPSD",0
-dev08	.db	"PPPSD",0
-dev09	.db	"HDSK",0
-dev10	.equ	devunk
-dev11	.equ	devunk
-dev12	.equ	devunk
-dev13	.equ	devunk
-dev14	.equ	devunk
-dev15	.equ	devunk
+prtall:
+	ld	a,BID_BIOS		; BIOS Bank please
+	ld	ix,$0406		; HBIOS PRTSUM vector
+	jp	HB_BNKCALL		; do it
 ;
 #endif
 ;
-;
-;
 #if (BIOS == BIOS_UNA)
 ;
 ; Print list of all drives (UNA)
 ;
 prtall:
+	ld	hl,str_devlst		; device list header string
+	call	pstr			; display it
 	call	nl			; formatting
 	ld	b,0			; start with unit 0
 ;
@@ -1985,6 +1910,8 @@ devsd		.db	"SD",0
 devdsd		.db	"DSD",0
 devunk		.db	"UNK",0
 ;
+str_devlst	.db	"\r\n\r\nDisk Devices:",0
+;
 #endif
 ;
 ;=======================================================================
@@ -2078,7 +2005,6 @@ str_reboot	.db	"\r\n\r\nRestarting System...",0
 str_newcon	.db	"\r\n\r\n  Console on Unit #",0
 str_chspeed	.db	"\r\n\r\n  Change speed now. Press a key to resume.",0
 str_applst	.db	"\r\n\r\nROM Applications:",0
-str_devlst	.db	"\r\n\r\nDisk Devices:",0
 str_invcmd	.db	"\r\n\r\n*** Invalid Command ***",bel,0
 str_load	.db	"\r\n\r\nLoading ",0
 str_disk	.db	"\r\n  Disk Unit ",0
diff --git a/Source/ver.inc b/Source/ver.inc
index 81181ce0..d458de48 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.197"
+#DEFINE BIOSVER	"3.1.1-pre.199"
diff --git a/Source/ver.lib b/Source/ver.lib
index b10a6bff..532c1458 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.197"
+	db	"3.1.1-pre.199"
 	endm