diff --git a/Doc/ChangeLog.txt b/Doc/ChangeLog.txt
index b5dc12ec..060105f6 100644
--- a/Doc/ChangeLog.txt
+++ b/Doc/ChangeLog.txt
@@ -1,7 +1,7 @@
 Version 3.1.1
 -------------
 - WBW: Version bumped due to pervasive changes
-- WBW: Preliminary support for hard disk partition support (backward compatible)
+- WBW: Preliminary hard disk partition support (backward compatible)
 
 Version 3.1
 -----------
diff --git a/Doc/RomWBW Applications.pdf b/Doc/RomWBW Applications.pdf
index 88b84919..dcf863fc 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 84168f95..8a116e0a 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 34fa97e8..eb0583ed 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 d147a2a1..65d14983 100644
Binary files a/Doc/RomWBW Getting Started.pdf and b/Doc/RomWBW Getting Started.pdf differ
diff --git a/Makefile b/Makefile
index 8253467c..65560c7d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,6 @@
 all:
 	$(MAKE) --directory Tools/unix
 	$(MAKE) --directory Source
-	$(MAKE) --directory Source/Images
 
 clean:
 	$(MAKE) --directory Tools/unix clean
diff --git a/ReadMe.md b/ReadMe.md
index bbd5b46e..34710692 100644
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -3,7 +3,7 @@
 ## Z80/Z180 System Software
 
 Version 3.1 Pre-release  
-Thursday 23 April 2020
+Friday 8 May 2020
 
 Wayne Warthen <wwarthen@gmail.com>
 
@@ -1137,8 +1137,8 @@ applications are no longer provided.
     driver.
   - Ed Brindley contributed some of the code that supports the RC2014
     platform.
-  - Phil Summers contributed Forth and BASIC in ROM as well as a long
-    list of general code enhancements.
+  - Phil Summers contributed Forth and BASIC in ROM, the AY-3-8910 sound
+    driver as well as a long list of general code enhancements.
   - Phillip Stevens contributed support for FreeRTOS.
   - Curt Mayer contributed the Linux / MacOS build process.
   - UNA BIOS and FDISK80 are the products of John Coffman.
diff --git a/ReadMe.txt b/ReadMe.txt
index 27ad0aa6..601e8101 100644
--- a/ReadMe.txt
+++ b/ReadMe.txt
@@ -3,7 +3,7 @@ RomWBW
 Z80/Z180 System Software
 
 Version 3.1 Pre-release
-Thursday 23 April 2020
+Friday 8 May 2020
 
 Wayne Warthen wwarthen@gmail.com
 
@@ -1169,8 +1169,8 @@ applications are no longer provided.
     driver.
 -   Ed Brindley contributed some of the code that supports the RC2014
     platform.
--   Phil Summers contributed Forth and BASIC in ROM as well as a long
-    list of general code enhancements.
+-   Phil Summers contributed Forth and BASIC in ROM, the AY-3-8910 sound
+    driver as well as a long list of general code enhancements.
 -   Phillip Stevens contributed support for FreeRTOS.
 -   Curt Mayer contributed the Linux / MacOS build process.
 -   UNA BIOS and FDISK80 are the products of John Coffman.
diff --git a/Source/Doc/Architecture.md b/Source/Doc/Architecture.md
index 330d7887..ffc3120e 100644
--- a/Source/Doc/Architecture.md
+++ b/Source/Doc/Architecture.md
@@ -1721,6 +1721,7 @@ available along with the registers/information returned.
 |      _Returned Values_
 |           A: Status (0=OK, else error)
 |           DE:HL: Current Timer Tick Count Value
+|           C: Tick frequency (typically 50 or 60)
 
 #### SYSGET Subfunction 0xD1 -- Get Seconds Count (SECONDS)
 
@@ -1806,15 +1807,6 @@ available along with the registers/information used as input.
 |      _Returned Values_
 |           A: Status (0=OK, else error)
 
-#### SYSSET Subfunction 0xD2 -- Inc Timer (TIMER)
-
-|      _Entry Parameters_
-|           BC: 0xF9D2
-
-|      _Returned Values_
-|           A: Status (0=OK, else error)
-
-
 #### SYSSET Subfunction 0xE0 -- Set Boot Information (BOOTINFO)
 
 |      _Entry Parameters_
diff --git a/Source/Doc/GettingStarted.md b/Source/Doc/GettingStarted.md
index dada3943..cd6bc2da 100644
--- a/Source/Doc/GettingStarted.md
+++ b/Source/Doc/GettingStarted.md
@@ -1190,8 +1190,8 @@ these applications are no longer provided.
 driver.
 * Ed Brindley contributed some of the code that supports the RC2014
 platform.
-* Phil Summers contributed Forth and BASIC in ROM as well as a long
-list of general code enhancements.
+* Phil Summers contributed Forth and BASIC in ROM, the AY-3-8910 sound
+driver as well as a long list of general code enhancements.
 * Phillip Stevens contributed support for FreeRTOS.
 * Curt Mayer contributed the Linux / MacOS build process.
 * UNA BIOS and FDISK80 are the products of John Coffman.
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index c51edd4d..fe3303e0 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -2458,6 +2458,7 @@ SYS_GETTIMER:
 	HB_DI
 	CALL	LD32
 	HB_EI
+	LD	C, TICKFREQ
 	XOR	A
 	RET
 ;
diff --git a/Source/HBIOS/sn76489.asm b/Source/HBIOS/sn76489.asm
index a59a5b1d..f8181983 100644
--- a/Source/HBIOS/sn76489.asm
+++ b/Source/HBIOS/sn76489.asm
@@ -116,7 +116,7 @@ SN7_VOLUME:
 
 SN7_NOTE:
 	AUDTRACE(SNT_NOTE)
-	AUDTRACE_L
+	AUDTRACE_HL
 	AUDTRACE_CR
 
 	LD	H,0
diff --git a/Source/ver.inc b/Source/ver.inc
index 3cb3dc77..783d72d7 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.3"
+#DEFINE BIOSVER	"3.1.1-pre.4"
diff --git a/Source/ver.lib b/Source/ver.lib
index 3c226412..450a4790 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.3"
+	db	"3.1.1-pre.4"
 	endm