diff --git a/Machines/Utility/ROMCatalogue.cpp b/Machines/Utility/ROMCatalogue.cpp
index b217c000e..410ac798c 100644
--- a/Machines/Utility/ROMCatalogue.cpp
+++ b/Machines/Utility/ROMCatalogue.cpp
@@ -540,6 +540,10 @@ Description::Description(Name name) {
 			*this = Description(name, "Electron", "the Electron MOS ROM v1.00", "os.rom", 16*1024, 0xbf63fb1fu);
 		break;
 
+		case Name::AcornRISCOS319:
+			*this = Description(name, "Archimedes", "RISC OS v3.19", "ROM319", 2*1024*1024, 0x00c7a3d3u);
+		break;
+
 		case Name::MasterSystemJapaneseBIOS:	*this = Description(name, "MasterSystem", "the Japanese Master System BIOS", "japanese-bios.sms", 8*1024, 0x48d44a13u); break;
 		case Name::MasterSystemWesternBIOS:		*this = Description(name, "MasterSystem", "the European/US Master System BIOS", "bios.sms", 8*1024, 0x0072ed54u);		break;
 
diff --git a/Machines/Utility/ROMCatalogue.hpp b/Machines/Utility/ROMCatalogue.hpp
index 4cec1b0da..a672e9522 100644
--- a/Machines/Utility/ROMCatalogue.hpp
+++ b/Machines/Utility/ROMCatalogue.hpp
@@ -22,7 +22,7 @@ namespace ROM {
 enum Name {
 	None,
 
-	// Acorn.
+	// Acorn Electron.
 	AcornBASICII,
 	AcornElectronMOS100,
 	PRESADFSSlot1,
@@ -31,6 +31,9 @@ enum Name {
 	PRESAdvancedPlus6,
 	Acorn1770DFS,
 
+	// Acorn Archimedes.
+	AcornRISCOS319,
+
 	// Amiga.
 	AmigaKickstart10,
 	AmigaKickstart11,
diff --git a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm
index 352de1907..e0456aed6 100644
--- a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
@@ -9,6 +9,7 @@
 #import <XCTest/XCTest.h>
 
 #include "../../../InstructionSets/ARM/Executor.hpp"
+#include "CSROMFetcher.hpp"
 
 using namespace InstructionSet::ARM;
 
@@ -41,15 +42,6 @@ struct Memory {
 
 @implementation ARMDecoderTests
 
-//- (void)testXYX {
-//	Executor<Memory> scheduler;
-//
-//	for(int c = 0; c < 65536; c++) {
-//		InstructionSet::ARM::dispatch(c << 16, scheduler);
-//	}
-//	InstructionSet::ARM::dispatch(0xEAE06900, scheduler);
-//}
-
 - (void)testBarrelShifterLogicalLeft {
 	uint32_t value;
 	uint32_t carry;
@@ -195,4 +187,12 @@ struct Memory {
 	XCTAssertEqual(carry, 0);
 }
 
+- (void)testROM319 {
+	constexpr ROM::Name rom_name = ROM::Name::AcornRISCOS319;
+	ROM::Request request(rom_name);
+	const auto roms = CSROMFetcher()(request);
+
+	NSLog(@"");
+}
+
 @end
diff --git a/ROMImages/Archimedes/readme.txt b/ROMImages/Archimedes/readme.txt
new file mode 100644
index 000000000..4dee93c33
--- /dev/null
+++ b/ROMImages/Archimedes/readme.txt
@@ -0,0 +1,5 @@
+ROM files would ordinarily go here; RISC OS remains a commercial product so these are not included with the emulator.
+
+Expected files:
+
+ROM319 — the RISC OS 3.19 ROM.
\ No newline at end of file