Added hacky segue into analysis for all Electron formats. Added analyser to try to differentiate Acorn-format ROMs from other things called .rom, which are likely to be numerous.

OSBindings/Mac/Clock Signal/Documents/ElectronDocument.swift

@@ -45,6 +45,8 @@ class ElectronDocument: MachineDocument {
 	}
 
 	override func readFromURL(url: NSURL, ofType typeName: String) throws {
+		electron.analyse(url)
+
 		if let pathExtension = url.pathExtension {
 			switch pathExtension.lowercaseString {
 				case "uef":

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSElectron.h

@@ -17,6 +17,8 @@
 - (void)setROM:(nonnull NSData *)rom slot:(int)slot;
 - (BOOL)openUEFAtURL:(nonnull NSURL *)URL;
 
+- (void)analyse:(NSURL *)url;
+
 @property (nonatomic, assign) BOOL useFastLoadingHack;
 @property (nonatomic, assign) BOOL useTelevisionOutput;
 

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSElectron.mm

@@ -10,6 +10,7 @@
 
 #include "Electron.hpp"
 #import "CSMachine+Subclassing.h"
+#include "StaticAnalyser.hpp"
 #include "TapeUEF.hpp"
 
 @implementation CSElectron {
@@ -20,6 +21,10 @@
 	return &_electron;
 }
 
+- (void)analyse:(NSURL *)url {
+	StaticAnalyser::GetTargets([url fileSystemRepresentation]);
+}
+
 - (void)setOSROM:(nonnull NSData *)rom {
 	@synchronized(self) {
 		_electron.set_rom(Electron::ROMSlotOS, rom.length, (const uint8_t *)rom.bytes);

Storage/Cartridge/Formats/AcornROM.cpp

@@ -8,8 +8,52 @@
 
 #include "AcornROM.hpp"
 
+#include <cstdio>
+#include <sys/stat.h>
+
 using namespace Storage::Cartridge;
 
 AcornROM::AcornROM(const char *file_name)
 {
+	// the file should be exactly 16 kb
+	struct stat file_stats;
+	stat(file_name, &file_stats);
+	if(file_stats.st_size != 0x4000) throw ErrorNotAcornROM;
+
+	// grab contents
+	FILE *file = fopen(file_name, "rb");
+	if(!file) throw ErrorNotAcornROM;
+	size_t data_length = (size_t)file_stats.st_size;
+	std::vector<uint8_t> contents(data_length);
+	fread(&contents[0], 1, (size_t)(data_length), file);
+	fclose(file);
+
+	// perform sanity checks...
+
+	// is a copyright string present?
+	uint8_t copyright_offset = contents[7];
+	if(
+		contents[copyright_offset] != 0x00 ||
+		contents[copyright_offset+1] != 0x28 ||
+		contents[copyright_offset+2] != 0x43 ||
+		contents[copyright_offset+3] != 0x29
+	) throw ErrorNotAcornROM;
+
+	// is the language entry point valid?
+	if(!(
+		(contents[0] == 0x00 && contents[1] == 0x00 && contents[2] == 0x00) ||
+		(contents[0] != 0x00 && contents[2] >= 0x80 && contents[2] < 0xc0)
+		)) throw ErrorNotAcornROM;
+
+	// is the service entry point valid?
+	if(!(contents[5] >= 0x80 && contents[5] < 0xc0)) throw ErrorNotAcornROM;
+
+	// probability of a random binary blob that isn't an Acorn ROM proceeding to here:
+	//		1/(2^32) *
+	//		( ((2^24)-1)/(2^24)*(1/4)		+		1/(2^24)	) *
+	//		1/4
+	//	= something very improbable — around 1/16th of 1 in 2^32, but not exactly.
+
+	// enshrine
+	_segments.emplace_back(0x8000, 0xc000, std::move(contents));
 }