diff --git a/README.md b/README.md
index e6c984e1..2556ef33 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,8 @@
 
 #### Gerardo Ospina has implemented a Manchester University SSEM (Small Scale Experimental Machine) simulator.
 
+#### Richard Cornwell has implemented a Burroughs B5500 simulator.
+
 #### Updated AltairZ80 simulator from Peter Schorn.
 
 #### Updated HP2100 simulator from Dave Bryan.
diff --git a/Visual Studio Projects/B5500.vcproj b/Visual Studio Projects/B5500.vcproj
new file mode 100644
index 00000000..15483ebd
--- /dev/null
+++ b/Visual Studio Projects/B5500.vcproj	
@@ -0,0 +1,345 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9.00"
+	Name="B5500"
+	ProjectGUID="{BA514FA1-D029-4D25-91CC-255E5953FF6E}"
+	RootNamespace="B5500"
+	Keyword="Win32Proj"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="..\BIN\NT\$(PlatformName)-$(ConfigurationName)"
+			IntermediateDirectory="..\BIN\NT\Project\simh\$(ProjectName)\$(PlatformName)-$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="$(VCInstallDir)VCProjectDefaults\UpgradeFromVC71.vsprops"
+			CharacterSet="0"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+				Description="Check for required build dependencies &amp; git commit id"
+				CommandLine="Pre-Build-Event.cmd LIBPCRE"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="./;../;../../windows-build/PCRE/include/"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_WINSOCK_DEPRECATED_NO_WARNINGS;SIM_NEED_GIT_COMMIT_ID;HAVE_PCREPOSIX_H;PCRE_STATIC"
+				KeepComments="false"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="1"
+				UsePrecompiledHeader="0"
+				WarningLevel="3"
+				DebugInformationFormat="3"
+				CompileAs="1"
+				ShowIncludes="false"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="wsock32.lib winmm.lib pcrestaticd.lib pcreposixstaticd.lib"
+				LinkIncremental="2"
+				AdditionalLibraryDirectories="../../windows-build/PCRE/lib/"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				StackReserveSize="10485760"
+				StackCommitSize="10485760"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="..\BIN\NT\$(PlatformName)-$(ConfigurationName)"
+			IntermediateDirectory="..\BIN\NT\Project\simh\$(ProjectName)\$(PlatformName)-$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="$(VCInstallDir)VCProjectDefaults\UpgradeFromVC71.vsprops"
+			CharacterSet="0"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+				Description="Check for required build dependencies &amp; git commit id"
+				CommandLine="Pre-Build-Event.cmd LIBPCRE"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="./;../;../../windows-build/PCRE/include/"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_WARNINGS;_CRT_SECURE_NO_WARNINGS;_WINSOCK_DEPRECATED_NO_WARNINGS;SIM_NEED_GIT_COMMIT_ID;HAVE_PCREPOSIX_H;PCRE_STATIC"
+				StringPooling="true"
+				RuntimeLibrary="0"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				WarningLevel="3"
+				DebugInformationFormat="3"
+				CompileAs="1"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="wsock32.lib winmm.lib pcrestatic.lib pcreposixstatic.lib"
+				LinkIncremental="1"
+				AdditionalLibraryDirectories="../../windows-build/PCRE/lib/"
+				GenerateDebugInformation="false"
+				SubSystem="1"
+				StackReserveSize="10485760"
+				StackCommitSize="10485760"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm"
+			>
+			<File
+				RelativePath="..\B5500\b5500_cpu.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_dk.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_dr.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_dtc.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_io.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_mt.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_sys.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\b5500_urec.c"
+				>
+			</File>
+			<File
+				RelativePath="..\scp.c"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\sim_card.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_console.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_disk.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_ether.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_fio.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_serial.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_sock.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_tape.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_timer.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_tmxr.c"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_video.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc"
+			>
+			<File
+				RelativePath="..\B5500\b5500_defs.h"
+				>
+			</File>
+			<File
+				RelativePath="..\scp.h"
+				>
+			</File>
+			<File
+				RelativePath="..\B5500\sim_card.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_console.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_defs.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_disk.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_ether.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_fio.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_rev.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_serial.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_sock.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_tape.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_timer.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_tmxr.h"
+				>
+			</File>
+			<File
+				RelativePath="..\sim_video.h"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/Visual Studio Projects/Simh.sln b/Visual Studio Projects/Simh.sln
index 483d9e33..b886c37c 100644
--- a/Visual Studio Projects/Simh.sln	
+++ b/Visual Studio Projects/Simh.sln	
@@ -218,6 +218,11 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "isys8020", "isys8020.vcproj
 		{D40F3AF1-EEE7-4432-9807-2AD287B490F8} = {D40F3AF1-EEE7-4432-9807-2AD287B490F8}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "B5500", "B5500.vcproj", "{BA514FA1-D029-4D25-91CC-255E5953FF6E}"
+	ProjectSection(ProjectDependencies) = postProject
+		{D40F3AF1-EEE7-4432-9807-2AD287B490F8} = {D40F3AF1-EEE7-4432-9807-2AD287B490F8}
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Win32 = Debug|Win32
@@ -400,6 +405,10 @@ Global
 		{9BBA76FE-45DD-4902-9421-BEA3EC2DCDB0}.Debug|Win32.Build.0 = Debug|Win32
 		{9BBA76FE-45DD-4902-9421-BEA3EC2DCDB0}.Release|Win32.ActiveCfg = Release|Win32
 		{9BBA76FE-45DD-4902-9421-BEA3EC2DCDB0}.Release|Win32.Build.0 = Release|Win32
+		{BA514FA1-D029-4D25-91CC-255E5953FF6E}.Debug|Win32.ActiveCfg = Debug|Win32
+		{BA514FA1-D029-4D25-91CC-255E5953FF6E}.Debug|Win32.Build.0 = Debug|Win32
+		{BA514FA1-D029-4D25-91CC-255E5953FF6E}.Release|Win32.ActiveCfg = Release|Win32
+		{BA514FA1-D029-4D25-91CC-255E5953FF6E}.Release|Win32.Build.0 = Release|Win32
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/descrip.mms b/descrip.mms
index 3bf22901..003bc8d5 100644
--- a/descrip.mms
+++ b/descrip.mms
@@ -19,6 +19,7 @@
 #            ALTAIR          Just Build The MITS Altair.
 #            ALTAIRZ80       Just Build The MITS Altair Z80.
 #            BESM6           Just Build The BESM-6.
+#            B5500           Just Build The B5500.
 #            ECLIPSE         Just Build The Data General Eclipse.
 #            GRI             Just Build The GRI Corporation GRI-909.
 #            LGP             Just Build The Royal-McBee LGP-30.
@@ -630,7 +631,6 @@ SWTP6800MP_A2_SOURCE = $(SWTP6800MP_A2_COMMON)mp-a2.c,$(SWTP6800MP_A2_COMMON)m68
 	$(SWTP6800MP_A2_COMMON)mp-8m.c,$(SWTP6800MP_A2_COMMON)i2716.c
 SWTP6800MP_A2_OPTIONS = /INCL=($(SIMH_DIR),$(SWTP6800MP_A2_DIR))/DEF=($(CC_DEFS))
 
-
 #
 # BESM6
 #
@@ -642,6 +642,16 @@ BESM6_SOURCE = $(BESM6_DIR)BESM6_CPU.C,$(BESM6_DIR)BESM6_SYS.C,$(BESM6_DIR)BESM6
 	$(BESM6_DIR)BESM6_PUNCH.C
 BESM6_OPTIONS = /INCL=($(SIMH_DIR),$(BESM6_DIR))/DEF=($(CC_DEFS),"USE_INT64=1")
 
+#
+# B5500
+#
+B5500_DIR = SYS$DISK:[.B5500]
+B5500_LIB = $(LIB_DIR)B5500-$(ARCH).OLB
+B5500_SOURCE = $(B5500_DIR)B5500_CPU.C,$(B5500_DIR)B5500_DK.C,$(B5500_DIR)B5500_DR.C,\
+	$(B5500_DIR)B5500_DTC.C,$(B5500_DIR)B5500_IO.C,$(B5500_DIR)B5500_MT.C,\
+	$(B5500_DIR)B5500_SYS.C,$(B5500_DIR)B5500_UREC.C,$(B5500_DIR)SIM_CARD.C
+B5500_OPTIONS = /INCL=($(SIMH_DIR),$(B5500_DIR))/DEF=($(CC_DEFS),"USE_INT64=1")
+
 #
 # Digital Equipment VAX 3900 Simulator Definitions.
 #
@@ -904,7 +914,7 @@ I7094_OPTIONS = /INCL=($(SIMH_DIR),$(I7094_DIR))/DEF=($(CC_DEFS))
 ALL : ALTAIR ALTAIRZ80 ECLIPSE GRI LGP H316 HP2100 I1401 I1620 IBM1130 ID16 \
       ID32 NOVA PDP1 PDP4 PDP7 PDP8 PDP9 PDP10 PDP11 PDP15 S3 \
       VAX MICROVAX3900 MICROVAX1 RTVAX1000 MICROVAX2 VAX730 VAX750 VAX780 VAX8600 \
-      SDS I7094 SWTP6800MP-A SWTP6800MP-A2 SSEM BESM6
+      SDS I7094 SWTP6800MP-A SWTP6800MP-A2 SSEM BESM6 B5500
         $! No further actions necessary
 .ELSE
 #
@@ -1329,6 +1339,10 @@ $(SWTP6800MP_A2_LIB) : $(SWTP6800MP_A2_SOURCE)
         $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
 
+#
+# If Not On VAX, Build The BESM6 Library.
+#
+.IFDEF ALPHA_OR_IA64
 $(BESM6_LIB) : $(BESM6_SOURCE)
         $!
         $! Building The $(BESM6_LIB) Library.
@@ -1339,6 +1353,37 @@ $(BESM6_LIB) : $(BESM6_SOURCE)
              LIBRARY/CREATE $(MMS$TARGET)
         $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+.ELSE
+#
+# We Are On VAX And Due To The Use of INT64 We Can't Build It.
+#
+$(BESM6_LIB) : 
+        $! Due To The Use Of INT64 We Can't Build The
+        $! $(MMS$TARGET) Library On VAX.
+.ENDIF
+
+#
+# If Not On VAX, Build The Burroughs B5500 Library.
+#
+.IFDEF ALPHA_OR_IA64
+$(B5500_LIB) : $(B5500_SOURCE)
+        $!
+        $! Building The $(B5500_LIB) Library.
+        $!
+        $ $(CC)$(B5500_OPTIONS) -
+               /OBJ=$(BLD_DIR) $(MMS$CHANGED_LIST)
+        $ IF (F$SEARCH("$(MMS$TARGET)").EQS."") THEN -
+             LIBRARY/CREATE $(MMS$TARGET)
+        $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+.ELSE
+#
+# We Are On VAX And Due To The Use of INT64 We Can't Build It.
+#
+$(B5500_LIB) : 
+        $! Due To The Use Of INT64 We Can't Build The
+        $! $(MMS$TARGET) Library On VAX.
+.ENDIF
 
 $(VAX_LIB1) : $(VAX_SOURCE1)
         $!
@@ -1904,6 +1949,10 @@ $(BIN_DIR)SWTP6800MP-A2-$(ARCH).EXE : $(SIMH_MAIN) $(SIMH_NONET_LIB) $(SWTP6800M
                $(BLD_DIR)SCP.OBJ,$(SWTP6800MP_A2_LIB)/LIBRARY,$(SIMH_NONET_LIB)/LIBRARY
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
 
+#
+# If Not On VAX, Build The BESM6 Simulator.
+#
+.IFDEF ALPHA_OR_IA64
 BESM6 : $(BIN_DIR)BESM6-$(ARCH).EXE
         $! BESM6 done
 
@@ -1915,6 +1964,42 @@ $(BIN_DIR)BESM6-$(ARCH).EXE : $(SIMH_MAIN) $(SIMH_NONET_LIB) $(BESM6_LIB)
         $ LINK $(LINK_DEBUG)/EXE=$(BIN_DIR)BESM6-$(ARCH).EXE -
                  $(BLD_DIR)SCP.OBJ,$(BESM6_LIB)/LIBRARY,$(SIMH_NONET_LIB)/LIBRARY
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+.ELSE
+#
+# Else We Are On VAX And Tell The User We Can't Build On VAX
+# Due To The Use Of INT64.
+#
+BESM6 : 
+        $! Sorry, Can't Build $(BIN_DIR)BESM6-$(ARCH).EXE Simulator
+        $! Because It Requires The Use Of INT64.
+.ENDIF
+
+
+#
+# If Not On VAX, Build The Burroughs B5500 Simulator.
+#
+.IFDEF ALPHA_OR_IA64
+B5500 : $(BIN_DIR)B5500-$(ARCH).EXE
+        $! B5500 done
+
+$(BIN_DIR)B5500-$(ARCH).EXE : $(SIMH_MAIN) $(SIMH_NONET_LIB) $(B5500_LIB)
+        $!
+        $! Building The $(BIN_DIR)B5500-$(ARCH).EXE Simulator.
+        $!
+        $ $(CC)$(B5500_OPTIONS)/OBJ=$(BLD_DIR) SCP.C
+        $ LINK $(LINK_DEBUG)/EXE=$(BIN_DIR)B5500-$(ARCH).EXE -
+                 $(BLD_DIR)SCP.OBJ,$(B5500_LIB)/LIBRARY,$(SIMH_NONET_LIB)/LIBRARY
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+.ELSE
+#
+# Else We Are On VAX And Tell The User We Can't Build On VAX
+# Due To The Use Of INT64.
+#
+B5500 : 
+        $! Sorry, Can't Build $(BIN_DIR)B5500-$(ARCH).EXE Simulator
+        $! Because It Requires The Use Of INT64.
+.ENDIF
+
 
 VAX : MICROVAX3900
         $! MICROVAX3900 aka VAX done
diff --git a/makefile b/makefile
index 894fe08a..b2cc8927 100644
--- a/makefile
+++ b/makefile
@@ -1248,6 +1248,12 @@ SSEMD = SSEM
 SSEM = ${SSEMD}/ssem_cpu.c ${SSEMD}/ssem_sys.c
 SSEM_OPT = -I ${SSEMD}
 
+B5500D = B5500
+B5500 = ${B5500D}/b5500_cpu.c ${B5500D}/b5500_io.c ${B5500D}/b5500_sys.c \
+	${B5500D}/b5500_dk.c ${B5500D}/b5500_mt.c ${B5500D}/b5500_urec.c \
+	${B5500D}/b5500_dr.c ${B5500D}/b5500_dtc.c ${B5500D}/sim_card.c
+B5500_OPT = -I.. -DUSE_INT64 -DB5500
+
 ###
 ### Experimental simulators
 ###
@@ -1336,7 +1342,8 @@ ALL = pdp1 pdp4 pdp7 pdp8 pdp9 pdp15 pdp11 pdp10 \
 	vax microvax3900 microvax1 rtvax1000 microvax2 vax730 vax750 vax780 vax8600 \
 	nova eclipse hp2100 i1401 i1620 s3 altair altairz80 gri \
 	i7094 ibm1130 id16 id32 sds lgp h316 \
-	swtp6800mp-a swtp6800mp-a2 tx-0 ssem isys8010 isys8020
+	swtp6800mp-a swtp6800mp-a2 tx-0 ssem isys8010 isys8020 \
+	b5500
 
 all : ${ALL}
 
@@ -1641,6 +1648,12 @@ ${BIN}pdq3${EXE} : ${PDQ3} ${SIM}
 	${MKDIRBIN}
 	${CC} ${PDQ3} ${SIM} ${PDQ3_OPT} $(CC_OUTSPEC) ${LDFLAGS}
 
+b5500 : $(BIN)b5500$(EXE)
+
+${BIN}b5500${EXE} : ${B5500} ${SIM} 
+	${MKDIRBIN}
+	${CC} ${B5500} ${SIM} ${B5500_OPT} $(CC_OUTSPEC) ${LDFLAGS}
+
 # Front Panel API Demo/Test program
 
 frontpaneltest : ${BIN}frontpaneltest${EXE}