diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index 711388af2..5e9773ab7 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj	
@@ -247,6 +247,7 @@
 		4B83348C1F5DB99C0097E338 /* 6522Base.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B83348B1F5DB99C0097E338 /* 6522Base.cpp */; };
 		4B8334951F5E25B60097E338 /* C1540.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B8334941F5E25B60097E338 /* C1540.cpp */; };
 		4B85322D227793CB00F26553 /* etos192uk.trace.txt.gz in Resources */ = {isa = PBXBuildFile; fileRef = 4B85322C227793CA00F26553 /* etos192uk.trace.txt.gz */; };
+		4B85322F2277ABDE00F26553 /* tos100.trace.txt.gz in Resources */ = {isa = PBXBuildFile; fileRef = 4B85322E2277ABDD00F26553 /* tos100.trace.txt.gz */; };
 		4B86E25B1F8C628F006FAA45 /* Keyboard.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B86E2591F8C628F006FAA45 /* Keyboard.cpp */; };
 		4B8805F01DCFC99C003085B1 /* Acorn.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B8805EE1DCFC99C003085B1 /* Acorn.cpp */; };
 		4B8805F41DCFD22A003085B1 /* Commodore.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B8805F21DCFD22A003085B1 /* Commodore.cpp */; };
@@ -966,6 +967,7 @@
 		4B8334941F5E25B60097E338 /* C1540.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = C1540.cpp; path = Implementation/C1540.cpp; sourceTree = "<group>"; };
 		4B85322922778E4200F26553 /* Comparative68000.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Comparative68000.hpp; sourceTree = "<group>"; };
 		4B85322C227793CA00F26553 /* etos192uk.trace.txt.gz */ = {isa = PBXFileReference; lastKnownFileType = archive.gzip; path = etos192uk.trace.txt.gz; sourceTree = "<group>"; };
+		4B85322E2277ABDD00F26553 /* tos100.trace.txt.gz */ = {isa = PBXFileReference; lastKnownFileType = archive.gzip; path = tos100.trace.txt.gz; sourceTree = "<group>"; };
 		4B86E2591F8C628F006FAA45 /* Keyboard.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Keyboard.cpp; sourceTree = "<group>"; };
 		4B86E25A1F8C628F006FAA45 /* Keyboard.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = Keyboard.hpp; sourceTree = "<group>"; };
 		4B8805EE1DCFC99C003085B1 /* Acorn.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Acorn.cpp; path = Parsers/Acorn.cpp; sourceTree = "<group>"; };
@@ -2262,6 +2264,7 @@
 		4B85322B227793CA00F26553 /* TOS Startup */ = {
 			isa = PBXGroup;
 			children = (
+				4B85322E2277ABDD00F26553 /* tos100.trace.txt.gz */,
 				4B85322C227793CA00F26553 /* etos192uk.trace.txt.gz */,
 			);
 			path = "TOS Startup";
@@ -3563,6 +3566,7 @@
 				4BB299C41B587D8400A49093 /* sbca in Resources */,
 				4BB298F41B587D8400A49093 /* adcay in Resources */,
 				4B44EBF51DC987AF00A7820C /* AllSuiteA.bin in Resources */,
+				4B85322F2277ABDE00F26553 /* tos100.trace.txt.gz in Resources */,
 				4BB299C61B587D8400A49093 /* sbcay in Resources */,
 				4BB299601B587D8400A49093 /* insa in Resources */,
 				4BB299951B587D8400A49093 /* mmufetch in Resources */,
diff --git a/OSBindings/Mac/Clock SignalTests/EmuTOSTests.mm b/OSBindings/Mac/Clock SignalTests/EmuTOSTests.mm
index ea52fda2b..9bf01b93b 100644
--- a/OSBindings/Mac/Clock SignalTests/EmuTOSTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/EmuTOSTests.mm	
@@ -101,13 +101,20 @@ class EmuTOS: public ComparativeBusHandler {
 	std::unique_ptr<EmuTOS> _machine;
 }
 
-- (void)testEmuTOSStartup {
-    const auto roms = CSROMFetcher()("AtariST", {"etos192uk.img"});
-	NSString *const traceLocation = [[NSBundle bundleForClass:[self class]] pathForResource:@"etos192uk" ofType:@"trace.txt.gz"];
+- (void)testImage:(NSString *)image trace:(NSString *)trace length:(int)length {
+    const auto roms = CSROMFetcher()("AtariST", { image.UTF8String });
+	NSString *const traceLocation = [[NSBundle bundleForClass:[self class]] pathForResource:trace ofType:@"trace.txt.gz"];
     _machine.reset(new EmuTOS(*roms[0], traceLocation.UTF8String));
-    _machine->run_for(HalfCycles(313515));
+    _machine->run_for(HalfCycles(length));
+}
 
+- (void)testEmuTOSStartup {
+	[self testImage:@"etos192uk.img" trace:@"etos192uk" length:313515];
     // TODO: assert that machine is now STOPped.
 }
 
+- (void)testTOSStartup {
+	[self testImage:@"tos100.img" trace:@"tos100" length:54011091];
+}
+
 @end
diff --git a/OSBindings/Mac/Clock SignalTests/TOS Startup/etos192uk.trace.txt.gz b/OSBindings/Mac/Clock SignalTests/TOS Startup/etos192uk.trace.txt.gz
new file mode 100644
index 000000000..386be16ff
Binary files /dev/null and b/OSBindings/Mac/Clock SignalTests/TOS Startup/etos192uk.trace.txt.gz differ
diff --git a/OSBindings/Mac/Clock SignalTests/TOS Startup/tos100.trace.txt.gz b/OSBindings/Mac/Clock SignalTests/TOS Startup/tos100.trace.txt.gz
new file mode 100644
index 000000000..e069b5f48
Binary files /dev/null and b/OSBindings/Mac/Clock SignalTests/TOS Startup/tos100.trace.txt.gz differ