diff --git a/examples/chapter11_07a/chapter11_07a.cppproj b/examples/chapter11_07a/chapter11_07a.cppproj
index 3e15b3d1a..f7c26496e 100644
--- a/examples/chapter11_07a/chapter11_07a.cppproj
+++ b/examples/chapter11_07a/chapter11_07a.cppproj
@@ -60,53 +60,53 @@
     <OutputFileExtension>.elf</OutputFileExtension>
     <ToolchainSettings>
       <AvrGccCpp>
-  <avrgcc.common.Device>-mmcu=atmega328p -B "%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\gcc\dev\atmega328p"</avrgcc.common.Device>
-  <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-  <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-  <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-  <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-  <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-  <avrgcc.compiler.directories.IncludePaths>
-    <ListValues>
-      <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\include</Value>
-      <Value>../src/os/FreeRTOS/Source/include/cfg/GCC-ATMega328</Value>
-      <Value>../src/os/FreeRTOS/Source/portable/GCC-ATMega328</Value>
-      <Value>../src/os/FreeRTOS/Source/include</Value>
-    </ListValues>
-  </avrgcc.compiler.directories.IncludePaths>
-  <avrgcc.compiler.optimization.level>Optimize more (-O2)</avrgcc.compiler.optimization.level>
-  <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
-  <avrgcc.compiler.warnings.Pedantic>True</avrgcc.compiler.warnings.Pedantic>
-  <avrgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -Wno-int-to-pointer-cast -Wno-pointer-to-int-cast</avrgcc.compiler.miscellaneous.OtherFlags>
-  <avrgcccpp.compiler.directories.IncludePaths>
-    <ListValues>
-      <Value>../src/mcal/avr</Value>
-      <Value>../src/os/FreeRTOS/Source/include</Value>
-      <Value>../src/os/FreeRTOS/Source/include/cfg/GCC-ATMega328</Value>
-      <Value>../src/os/FreeRTOS/Source/portable/GCC-ATMega328</Value>
-      <Value>../src/app</Value>
-      <Value>../src</Value>
-      <Value>../src/util/STL</Value>
-      <Value>../src/util/STL_C++XX_stdfloat</Value>
-    </ListValues>
-  </avrgcccpp.compiler.directories.IncludePaths>
-  <avrgcccpp.compiler.optimization.level>Optimize more (-O2)</avrgcccpp.compiler.optimization.level>
-  <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>False</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
-  <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>False</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
-  <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
-  <avrgcccpp.compiler.warnings.Pedantic>True</avrgcccpp.compiler.warnings.Pedantic>
-  <avrgcccpp.compiler.miscellaneous.OtherFlags>-Wextra -gdwarf-2 -fno-use-cxa-atexit -fno-exceptions -finline-functions -finline-limit=64 -std=c++14 -fno-rtti -fno-nonansi-builtins -fno-threadsafe-statics -fno-enforce-eh-specs</avrgcccpp.compiler.miscellaneous.OtherFlags>
-  <avrgcccpp.linker.general.DoNotUseStandardStartFiles>True</avrgcccpp.linker.general.DoNotUseStandardStartFiles>
-  <avrgcccpp.linker.general.DoNotUseDefaultLibraries>True</avrgcccpp.linker.general.DoNotUseDefaultLibraries>
-  <avrgcccpp.linker.general.NoStartupOrDefaultLibs>True</avrgcccpp.linker.general.NoStartupOrDefaultLibs>
-  <avrgcccpp.linker.memorysettings.InitialStack>0x800</avrgcccpp.linker.memorysettings.InitialStack>
-  <avrgcccpp.linker.miscellaneous.LinkerFlags>-Wl,-T../target/micros/avr/make/avr.ld</avrgcccpp.linker.miscellaneous.LinkerFlags>
-  <avrgcccpp.assembler.general.IncludePaths>
-    <ListValues>
-      <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\include</Value>
-    </ListValues>
-  </avrgcccpp.assembler.general.IncludePaths>
-</AvrGccCpp>
+        <avrgcc.common.Device>-mmcu=atmega328p -B "%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\gcc\dev\atmega328p"</avrgcc.common.Device>
+        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
+        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
+        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
+        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
+        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
+        <avrgcc.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\include</Value>
+            <Value>../src/os/FreeRTOS/Source/include/cfg/GCC-ATMega328</Value>
+            <Value>../src/os/FreeRTOS/Source/portable/GCC-ATMega328</Value>
+            <Value>../src/os/FreeRTOS/Source/include</Value>
+          </ListValues>
+        </avrgcc.compiler.directories.IncludePaths>
+        <avrgcc.compiler.optimization.level>Optimize more (-O2)</avrgcc.compiler.optimization.level>
+        <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
+        <avrgcc.compiler.warnings.Pedantic>True</avrgcc.compiler.warnings.Pedantic>
+        <avrgcc.compiler.miscellaneous.OtherFlags>-std=gnu99 -Wno-int-to-pointer-cast -Wno-pointer-to-int-cast</avrgcc.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>../src/mcal/avr</Value>
+            <Value>../src/os/FreeRTOS/Source/include</Value>
+            <Value>../src/os/FreeRTOS/Source/include/cfg/GCC-ATMega328</Value>
+            <Value>../src/os/FreeRTOS/Source/portable/GCC-ATMega328</Value>
+            <Value>../src/app</Value>
+            <Value>../src</Value>
+            <Value>../src/util/STL</Value>
+            <Value>../src/util/STL_C++XX_stdfloat</Value>
+          </ListValues>
+        </avrgcccpp.compiler.directories.IncludePaths>
+        <avrgcccpp.compiler.optimization.level>Optimize more (-O2)</avrgcccpp.compiler.optimization.level>
+        <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>False</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
+        <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>False</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
+        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
+        <avrgcccpp.compiler.warnings.Pedantic>True</avrgcccpp.compiler.warnings.Pedantic>
+        <avrgcccpp.compiler.miscellaneous.OtherFlags>-Wextra -gdwarf-2 -fno-use-cxa-atexit -fno-exceptions -finline-functions -finline-limit=64 -std=c++14 -fno-rtti -fno-nonansi-builtins -fno-threadsafe-statics -fno-enforce-eh-specs</avrgcccpp.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.linker.general.DoNotUseStandardStartFiles>True</avrgcccpp.linker.general.DoNotUseStandardStartFiles>
+        <avrgcccpp.linker.general.DoNotUseDefaultLibraries>True</avrgcccpp.linker.general.DoNotUseDefaultLibraries>
+        <avrgcccpp.linker.general.NoStartupOrDefaultLibs>True</avrgcccpp.linker.general.NoStartupOrDefaultLibs>
+        <avrgcccpp.linker.memorysettings.InitialStack>0x800</avrgcccpp.linker.memorysettings.InitialStack>
+        <avrgcccpp.linker.miscellaneous.LinkerFlags>-Wl,-T../target/micros/avr/make/avr.ld</avrgcccpp.linker.miscellaneous.LinkerFlags>
+        <avrgcccpp.assembler.general.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.3.300\include</Value>
+          </ListValues>
+        </avrgcccpp.assembler.general.IncludePaths>
+      </AvrGccCpp>
     </ToolchainSettings>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
@@ -159,6 +159,7 @@
     <Folder Include="src\math\" />
     <Folder Include="src\math\checksums" />
     <Folder Include="src\math\checksums\crc" />
+    <Folder Include="src\math\checksums\hash" />
     <Folder Include="src\mcal_led\" />
     <Folder Include="src\mcal_memory" />
     <Folder Include="src\mcal_spi" />
@@ -210,6 +211,21 @@
     <Compile Include="src\math\checksums\crc\crc32.h">
       <SubType>compile</SubType>
     </Compile>
+    <Compile Include="src\math\checksums\hash\hash_base.h">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="src\math\checksums\hash\hash_detail.h">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="src\math\checksums\hash\hash_sha1.h">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="src\math\checksums\hash\hash_sha256.h">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="src\math\checksums\hash\hash_stream_base.h">
+      <SubType>compile</SubType>
+    </Compile>
     <Compile Include="src\mcal\avr\mcal_benchmark.h">
       <SubType>compile</SubType>
     </Compile>
diff --git a/examples/chapter11_07a/images/board11_07a.jpg b/examples/chapter11_07a/images/board11_07a.jpg
new file mode 100644
index 000000000..433c491aa
Binary files /dev/null and b/examples/chapter11_07a/images/board11_07a.jpg differ
diff --git a/examples/chapter11_07a/readme.md b/examples/chapter11_07a/readme.md
index cadc47482..3e0bab770 100644
--- a/examples/chapter11_07a/readme.md
+++ b/examples/chapter11_07a/readme.md
@@ -69,5 +69,10 @@ The pin most important pin connections are shown in the tables below.
 | SCK        | portd.0                 |
 
 
-TODO: The hardware setup with the $4~\text{MByte}$ serial SRAM
-is pictured in the image below.
+The hardware setup with the $4~\text{MByte}$ serial SRAM
+is pictured in the image below. The scene shows the ARDUINO(R)
+with the external serial RAM executing cyclic, back-to-back $10,000$
+decimal digit $\pi$ calculations.
+One successful calculation is complete and the second one is well underway.
+
+![](./images/board11_07a.jpg)