diff --git a/Doc/ChangeLog.txt b/Doc/ChangeLog.txt
index c53feceb..dd2d09be 100644
--- a/Doc/ChangeLog.txt
+++ b/Doc/ChangeLog.txt
@@ -1,6 +1,7 @@
 Version 3.0.1
 -------------
 - WBW: Increase XModem timeout waiting for host to start sending
+- WBW: Update TMS driver to dynamically increase Z180 I/O W/S inside driver
 
 Version 3.0.0
 -------------
diff --git a/Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom.pdf b/Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom_v.1.1.pdf
similarity index 70%
rename from Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom.pdf
rename to Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom_v.1.1.pdf
index eb4d5b48..8a215aa1 100644
Binary files a/Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom.pdf and b/Doc/Contrib/SC126_How-To_No_1_Serial_Comms_Using_Minicom_v.1.1.pdf differ
diff --git a/Source/Apps/Tune/Tune.asm b/Source/Apps/Tune/Tune.asm
index 69374e39..73fe5b0e 100644
--- a/Source/Apps/Tune/Tune.asm
+++ b/Source/Apps/Tune/Tune.asm
@@ -38,6 +38,7 @@
 ;   2018-01-28 [WBW] Added support for MYM sound files
 ;   2019-11-21 [WBW] Added table-driven configuration
 ;   2020-02-11 [WBW] Made hardware config & detection more flexible
+;   2020-03-29 [WBW] Fix error in Z180 I/O W/S bracketing
 ;_______________________________________________________________________________
 ;
 ; ToDo:
@@ -124,8 +125,10 @@ PROBE:
 	LD	C,A			; ... to C
 	IN	A,(C)			; Read back value in register 2
 	CP	$AA			; Value as written?
-	JR	Z,MAT			; Hardware matched!
+	PUSH	AF			; Save AF
 	CALL	NORMIO			; Back to normal I/O speeds
+	POP	AF			; Recover AF
+	JR	Z,MAT			; Hardware matched!
 	JR	CFGSEL			; And keep trying
 ;
 MAT:
@@ -766,7 +769,7 @@ FILTYP		.DB	0	; Sound file type (TYPPT2, TYPPT3, TYPMYM)
 TMP		.DB	0	; work around use of undocumented Z80
 ;
 		
-MSGBAN		.DB	"Tune Player for RomWBW v2.4, 23-Mar-2020",0
+MSGBAN		.DB	"Tune Player for RomWBW v2.5, 29-Mar-2020",0
 MSGUSE		.DB	"Copyright (C) 2020, Wayne Warthen, GNU GPL v3",13,10
 		.DB	"PTxPlayer Copyright (C) 2004-2007 S.V.Bulba",13,10
 		.DB	"MYMPlay by Marq/Lieves!Tuore",13,10,13,10
diff --git a/Source/HBIOS/Config/N8_std.asm b/Source/HBIOS/Config/N8_std.asm
index f66b2692..d8654771 100644
--- a/Source/HBIOS/Config/N8_std.asm
+++ b/Source/HBIOS/Config/N8_std.asm
@@ -25,8 +25,8 @@
 #include "cfg_n8.asm"
 ;
 Z180_CLKDIV	.SET	1		; Z180: CHK DIV: 0=OSC/2, 1=OSC, 2=OSC*2
-Z180_MEMWAIT	.SET	1		; Z180: MEMORY WAIT STATES (0-3)
-Z180_IOWAIT	.SET	3		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
+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
 ;
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index 1d046bce..65db812a 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -34,8 +34,8 @@ RAMBIAS		.EQU	0		; OFFSET OF START OF RAM IN PHYSICAL ADDRESS SPACE
 ;
 Z180_BASE	.EQU	$40		; Z180: I/O BASE ADDRESS FOR INTERNAL REGISTERS
 Z180_CLKDIV	.EQU	1		; Z180: CHK DIV: 0=OSC/2, 1=OSC, 2=OSC*2
-Z180_MEMWAIT	.EQU	1		; Z180: MEMORY WAIT STATES (0-3)
-Z180_IOWAIT	.EQU	3		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
+Z180_MEMWAIT	.EQU	0		; Z180: MEMORY WAIT STATES (0-3)
+Z180_IOWAIT	.EQU	1		; Z180: I/O WAIT STATES TO ADD ABOVE 1 W/S BUILT-IN (0-3)
 ;
 N8_PPI0		.EQU	$80		; N8: FIRST PARALLEL PORT REGISTERS BASE ADR
 N8_PPI1		.EQU	$84		; N8: SECOND PARALLEL PORT REGISTERS BASE ADR
diff --git a/Source/HBIOS/tms.asm b/Source/HBIOS/tms.asm
index 2fb8b48a..4759cf61 100644
--- a/Source/HBIOS/tms.asm
+++ b/Source/HBIOS/tms.asm
@@ -51,11 +51,11 @@ TERMENABLE	.SET	TRUE		; INCLUDE TERMINAL PSEUDODEVICE DRIVER
 ; IF YOU SEE SCREEN CORRUPTION, ADJUST THIS!!!
 ;
 #IF (TMSMODE == TMSMODE_N8)
-; BELOW WAS TUNED FOR N8 AT 18MHZ WITH 3 IO WAIT STATES
-#DEFINE		TMS_IODELAY	NOP \ NOP \ NOP \ NOP \ NOP \ NOP \ NOP \ NOP
+; BELOW WAS TUNED FOR N8 AT 18MHZ
+#DEFINE		TMS_IODELAY	EX (SP),HL \ EX (SP),HL	; 38 W/S
 #ELSE
 ; BELOW WAS TUNED FOR SBC AT 8MHZ
-#DEFINE		TMS_IODELAY	NOP \ NOP
+#DEFINE		TMS_IODELAY	NOP \ NOP	; 8 W/S
 #ENDIF
 ;
 ;======================================================================
@@ -63,6 +63,10 @@ TERMENABLE	.SET	TRUE		; INCLUDE TERMINAL PSEUDODEVICE DRIVER
 ;======================================================================
 ;
 TMS_INIT:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
+;
 #IF (TMSMODE == TMSMODE_SCG)
 	LD	A,$FF
 	OUT	(TMS_ACR),A		; INIT AUX CONTROL REG
@@ -85,7 +89,7 @@ TMS_INIT:
 TMS_INIT1:
 	CALL 	TMS_CRTINIT		; SETUP THE TMS CHIP REGISTERS
 	CALL	TMS_LOADFONT		; LOAD FONT DATA FROM ROM TO TMS STRORAGE
-	CALL	TMS_VDARES
+	CALL	TMS_VDARES1
 #IF (TMSMODE == TMSMODE_N8)
 	CALL	PPK_INIT		; INITIALIZE KEYBOARD DRIVER
 #ENDIF
@@ -150,6 +154,10 @@ TMS_VDAQRY:
 	RET
 
 TMS_VDARES:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
+TMS_VDARES1:	; ENTRY POINT TO AVOID TMS_Z180IO RECURSION
 	LD	DE,0			; ROW = 0, COL = 0
 	CALL	TMS_XY			; SEND CURSOR TO TOP LEFT
 	LD	A,' '			; BLANK THE SCREEN
@@ -175,6 +183,9 @@ TMS_VDASCS:
 	CALL	PANIC		; NOT IMPLEMENTED (YET)
 	
 TMS_VDASCP:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
 	CALL	TMS_CLRCUR
 	CALL	TMS_XY		; SET CURSOR POSITION
 	CALL	TMS_SETCUR
@@ -190,6 +201,9 @@ TMS_VDASCO:
 	RET
 	
 TMS_VDAWRC:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
 	CALL	TMS_CLRCUR	; CURSOR OFF
 	LD	A,E		; CHARACTER TO WRITE GOES IN A
 	CALL	TMS_PUTCHAR	; PUT IT ON THE SCREEN
@@ -198,6 +212,9 @@ TMS_VDAWRC:
 	RET
 	
 TMS_VDAFIL:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
 	CALL	TMS_CLRCUR
 	LD	A,E		; FILL CHARACTER GOES IN A
 	EX	DE,HL		; FILL LENGTH GOES IN DE
@@ -207,6 +224,9 @@ TMS_VDAFIL:
 	RET
 
 TMS_VDACPY:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
 	CALL	TMS_CLRCUR
 	; LENGTH IN HL, SOURCE ROW/COL IN DE, DEST IS TMS_POS
 	; BLKCPY USES: HL=SOURCE, DE=DEST, BC=COUNT
@@ -220,6 +240,9 @@ TMS_VDACPY:
 	RET
 	
 TMS_VDASCR:
+#IF (CPUFAM == CPU_Z180)
+	CALL	TMS_Z180IO
+#ENDIF
 	CALL	TMS_CLRCUR
 TMS_VDASCR0:
 	LD	A,E		; LOAD E INTO A
@@ -689,6 +712,39 @@ TMS_BLKCPY3:
 ;
 	RET
 ;
+;----------------------------------------------------------------------
+; Z180 LOW SPEED I/O CODE BRACKETING
+;----------------------------------------------------------------------
+;
+#IF (CPUFAM == CPU_Z180)
+;
+TMS_Z180IO:
+	; HOOK CALLERS RETURN TO RESTORE DCNTL
+	EX	(SP),HL			; SAVE HL & HL := RET ADR
+	LD	(TMS_Z180IOR),HL	; SET RET ADR
+	LD	HL,TMS_Z180IOX		; HL := SPECIAL RETURN ADR
+	EX	(SP),HL			; RESTORE HL, INS NEW RET ADR
+	; SET Z180 MAX I/O WAIT STATES
+	PUSH	AF			; SAVE AF
+	IN0	A,(Z180_DCNTL)		; GET CURRENT Z180 DCNTL
+	LD	(TMS_DCNTL),A		; SAVE IT
+	OR	%00110000		; NEW DCNTL VALUE (MAX I/O W/S)
+	OUT0	(Z180_DCNTL),A		; IMPLEMENT IT
+	POP	AF			; RESTORE AF
+	; BACK TO CALLER
+TMS_Z180IOR	.EQU	$+1	
+	JP	$0000			; BACK TO CALLER
+;
+TMS_Z180IOX:
+	; RESTORE ORIGINAL DCNTL
+	PUSH	AF			; SAVE AF
+	LD	A,(TMS_DCNTL)		; ORIG DCNTL
+	OUT0	(Z180_DCNTL),A		; IMPLEMENT IT
+	POP	AF			; RESTORE AF
+	RET				; DONE
+;
+#ENDIF
+;
 ;==================================================================================================
 ;   TMS DRIVER - DATA
 ;==================================================================================================
@@ -751,6 +807,10 @@ TMS_INIT9918:
 ;
 TMS_INIT9918LEN	.EQU	$ - TMS_INIT9918
 ;
+#IF (CPUFAM == CPU_Z180)
+TMS_DCNTL	.DB	$00	; SAVE Z180 DCNTL AS NEEDED
+#ENDIF
+;
 ;==================================================================================================
 ;   TMS DRIVER - INSTANCE DATA
 ;==================================================================================================