diff --git a/configs/z80sim/README.txt b/configs/z80sim/README.txt
index 50be916e14d..ff9754c04e5 100644
--- a/configs/z80sim/README.txt
+++ b/configs/z80sim/README.txt
@@ -17,4 +17,18 @@ compatible with this build.  First start with the usual steps
   unpack
   cd sdcc
   ./configure
+
+But before making, we need to apply a patch to the SDCC 2.6.0 source
+so that the z80 assembler can handle long symbol names
+
+  Apply sdcc-2.6.0-asz80-symlen.patch
+  cd sdcc/device/lib
+
+Then make the SDCC binaries
+
+  cd sdcc
   make
+
+and install SDCC:
+
+  sudo make install
diff --git a/configs/z80sim/defconfig b/configs/z80sim/defconfig
index a993a6aeb1f..6141c34b13a 100644
--- a/configs/z80sim/defconfig
+++ b/configs/z80sim/defconfig
@@ -112,13 +112,13 @@ CONFIG_DEV_CONSOLE=n
 # o pthread_condtimedwait() depends on signals to wake
 #   up waiting tasks.
 #
-CONFIG_DISABLE_CLOCK=y
-CONFIG_DISABLE_POSIX_TIMERS=y
-CONFIG_DISABLE_PTHREAD=y
-CONFIG_DISABLE_SIGNALS=y
-CONFIG_DISABLE_MQUEUE=y
-CONFIG_DISABLE_MOUNTPOINT=y
-CONFIG_DISABLE_ENVIRON=y
+CONFIG_DISABLE_CLOCK=n
+CONFIG_DISABLE_POSIX_TIMERS=n
+CONFIG_DISABLE_PTHREAD=n
+CONFIG_DISABLE_SIGNALS=n
+CONFIG_DISABLE_MQUEUE=n
+CONFIG_DISABLE_MOUNTPOINT=n
+CONFIG_DISABLE_ENVIRON=n
 
 #
 # Misc libc settings
@@ -283,7 +283,7 @@ CONFIG_EXAMPLES_NSH_NETMASK=(255<<24|255<<16|255<<8|0)
 CONFIG_BOOT_FROM_FLASH=n
 CONFIG_CUSTOM_STACK=n
 CONFIG_PROC_STACK_SIZE=1024
-CONFIG_PTHREAD_STACK_MIN=
-CONFIG_PTHREAD_STACK_DEFAULT=
+CONFIG_PTHREAD_STACK_MIN=256
+CONFIG_PTHREAD_STACK_DEFAULT=1024
 CONFIG_HEAP_SIZE=
 CONFIG_HEAP_BASE=
diff --git a/configs/z80sim/sdcc-2.6.0-asz80-symlen.patch b/configs/z80sim/sdcc-2.6.0-asz80-symlen.patch
new file mode 100644
index 00000000000..d91c18d9882
--- /dev/null
+++ b/configs/z80sim/sdcc-2.6.0-asz80-symlen.patch
@@ -0,0 +1,11 @@
+--- sdcc/as/z80/asm.h	2007-12-30 16:49:53.000000000 -0600
++++ sdcc.orig/as/z80/asm.h	2007-12-30 16:49:14.000000000 -0600
+@@ -65,7 +65,7 @@
+ #define	RTTERM	')'		/* Right expression delimeter */
+ 
+ #ifdef SDK
+-#define	NCPS	80		/* characters per symbol */
++#define	NCPS	32		/* characters per symbol */
+ #else /* SDK */
+ #define NCPS	8		/* Chars. per symbol */
+ #endif /* SDK */