diff --git a/Source/HBIOS/Config/SCZ180_126.asm b/Source/HBIOS/Config/SCZ180_126.asm
index 09d2100a..9bb78400 100644
--- a/Source/HBIOS/Config/SCZ180_126.asm
+++ b/Source/HBIOS/Config/SCZ180_126.asm
@@ -32,6 +32,8 @@ 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)
 ;
+HBIOS_MUTEX	.SET	FALSE		; ENABLE REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
+;
 ASCIENABLE	.SET	TRUE		; ASCI: ENABLE Z180 ASCI SERIAL DRIVER (ASCI.ASM)
 ;
 ACIAENABLE	.SET	FALSE		; ACIA: ENABLE MOTOROLA 6850 ACIA DRIVER (ACIA.ASM)
@@ -46,4 +48,3 @@ PPIDEENABLE	.SET	FALSE		; PPIDE: ENABLE PARALLEL PORT IDE DISK DRIVER (PPIDE.ASM
 ;
 SDENABLE	.SET	TRUE		; SD: ENABLE SD CARD DISK DRIVER (SD.ASM)
 SDCNT		.SET	1		; SD: NUMBER OF SD CARD DEVICES (1-2), FOR DSD & SC ONLY
-
diff --git a/Source/HBIOS/Config/SCZ180_126_mtx.asm b/Source/HBIOS/Config/SCZ180_126_mtx.asm
deleted file mode 100644
index 69f4b091..00000000
--- a/Source/HBIOS/Config/SCZ180_126_mtx.asm
+++ /dev/null
@@ -1,27 +0,0 @@
-;
-;==================================================================================================
-;   SC126 STANDARD CONFIGURATION W/ HBIOS MUTEX
-;==================================================================================================
-;
-; THE COMPLETE SET OF DEFAULT CONFIGURATION SETTINGS FOR THIS PLATFORM ARE FOUND IN THE
-; CFG_<PLT>.ASM INCLUDED FILE WHICH IS FOUND IN THE PARENT DIRECTORY.  THIS FILE CONTAINS
-; COMMON CONFIGURATION SETTINGS THAT OVERRIDE THE DEFAULTS.  IT IS INTENDED THAT YOU MAKE
-; YOUR CUSTOMIZATIONS IN THIS FILE AND JUST INHERIT ALL OTHER SETTINGS FROM THE DEFAULTS.
-; EVEN BETTER, YOU CAN MAKE A COPY OF THIS FILE WITH A NAME LIKE <PLT>_XXX.ASM AND SPECIFY
-; YOUR FILE IN THE BUILD PROCESS.
-;
-; THE SETTINGS BELOW ARE THE SETTINGS THAT ARE MOST COMMONLY MODIFIED FOR THIS PLATFORM.
-; MANY OF THEM ARE EQUAL TO THE SETTINGS IN THE INCLUDED FILE, SO THEY DON'T REALLY DO
-; ANYTHING AS IS.  THEY ARE LISTED HERE TO MAKE IT EASY FOR YOU TO ADJUST THE MOST COMMON
-; SETTINGS.
-;
-; N.B., SINCE THE SETTINGS BELOW ARE REDEFINING VALUES ALREADY SET IN THE INCLUDED FILE,
-; TASM INSISTS THAT YOU USE THE .SET OPERATOR AND NOT THE .EQU OPERATOR BELOW. ATTEMPTING
-; TO REDEFINE A VALUE WITH .EQU BELOW WILL CAUSE TASM ERRORS!
-;
-; PLEASE REFER TO THE CUSTOM BUILD INSTRUCTIONS (README.TXT) IN THE SOURCE DIRECTORY (TWO
-; DIRECTORIES ABOVE THIS ONE).
-;
-#include "Config/SCZ180_126.asm"
-;
-HBIOS_MUTEX	.SET	TRUE		; PREVENT REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
diff --git a/Source/HBIOS/Config/SCZ180_130.asm b/Source/HBIOS/Config/SCZ180_130.asm
index ae332544..7ee6370d 100644
--- a/Source/HBIOS/Config/SCZ180_130.asm
+++ b/Source/HBIOS/Config/SCZ180_130.asm
@@ -32,7 +32,9 @@ 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)
 ;
-LEDENABLE	.SET	TRUE		; ENABLES STATUS LED (SINGLE LED)
+HBIOS_MUTEX	.SET	FALSE		; ENABLE REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
+;
+LEDENABLE	.SET	TRUE		; ENABLE STATUS LED (SINGLE LED)
 ;
 ASCIENABLE	.SET	TRUE		; ASCI: ENABLE Z180 ASCI SERIAL DRIVER (ASCI.ASM)
 ;
diff --git a/Source/HBIOS/Config/SCZ180_130_mtx.asm b/Source/HBIOS/Config/SCZ180_130_mtx.asm
deleted file mode 100644
index 99adaa91..00000000
--- a/Source/HBIOS/Config/SCZ180_130_mtx.asm
+++ /dev/null
@@ -1,27 +0,0 @@
-;
-;==================================================================================================
-;   SC130 STANDARD CONFIGURATION W/ HBIOS MUTEX
-;==================================================================================================
-;
-; THE COMPLETE SET OF DEFAULT CONFIGURATION SETTINGS FOR THIS PLATFORM ARE FOUND IN THE
-; CFG_<PLT>.ASM INCLUDED FILE WHICH IS FOUND IN THE PARENT DIRECTORY.  THIS FILE CONTAINS
-; COMMON CONFIGURATION SETTINGS THAT OVERRIDE THE DEFAULTS.  IT IS INTENDED THAT YOU MAKE
-; YOUR CUSTOMIZATIONS IN THIS FILE AND JUST INHERIT ALL OTHER SETTINGS FROM THE DEFAULTS.
-; EVEN BETTER, YOU CAN MAKE A COPY OF THIS FILE WITH A NAME LIKE <PLT>_XXX.ASM AND SPECIFY
-; YOUR FILE IN THE BUILD PROCESS.
-;
-; THE SETTINGS BELOW ARE THE SETTINGS THAT ARE MOST COMMONLY MODIFIED FOR THIS PLATFORM.
-; MANY OF THEM ARE EQUAL TO THE SETTINGS IN THE INCLUDED FILE, SO THEY DON'T REALLY DO
-; ANYTHING AS IS.  THEY ARE LISTED HERE TO MAKE IT EASY FOR YOU TO ADJUST THE MOST COMMON
-; SETTINGS.
-;
-; N.B., SINCE THE SETTINGS BELOW ARE REDEFINING VALUES ALREADY SET IN THE INCLUDED FILE,
-; TASM INSISTS THAT YOU USE THE .SET OPERATOR AND NOT THE .EQU OPERATOR BELOW. ATTEMPTING
-; TO REDEFINE A VALUE WITH .EQU BELOW WILL CAUSE TASM ERRORS!
-;
-; PLEASE REFER TO THE CUSTOM BUILD INSTRUCTIONS (README.TXT) IN THE SOURCE DIRECTORY (TWO
-; DIRECTORIES ABOVE THIS ONE).
-;
-#include "Config/SCZ180_130.asm"
-;
-HBIOS_MUTEX	.SET	TRUE		; PREVENT REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
diff --git a/Source/HBIOS/Config/SCZ180_131.asm b/Source/HBIOS/Config/SCZ180_131.asm
index 7824f728..9bdcbb99 100644
--- a/Source/HBIOS/Config/SCZ180_131.asm
+++ b/Source/HBIOS/Config/SCZ180_131.asm
@@ -32,7 +32,9 @@ 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)
 ;
-LEDENABLE	.SET	TRUE		; ENABLES STATUS LED (SINGLE LED)
+HBIOS_MUTEX	.SET	FALSE		; ENABLE REENTRANT CALLS TO HBIOS (ADDS OVERHEAD)
+;
+LEDENABLE	.SET	TRUE		; ENABLE STATUS LED (SINGLE LED)
 ;
 DIAGENABLE	.SET	FALSE		; ENABLES OUTPUT TO 8 BIT LED DIAGNOSTIC PORT
 ;
@@ -52,4 +54,3 @@ IDEENABLE	.SET	FALSE		; 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)
-;