Adds some notes-to-self on SCSI and a route to using Acorn's ADFS.

Analyser/Static/Acorn/StaticAnalyser.cpp

@@ -61,10 +61,6 @@ static std::vector<std::shared_ptr<Storage::Cartridge::Cartridge>>
 
 Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &media, const std::string &, TargetPlatform::IntType) {
 	auto target = std::make_unique<Target>();
-	target->confidence = 0.5; // TODO: a proper estimation
-	target->has_dfs = false;
-	target->has_adfs = false;
-	target->should_shift_restart = false;
 
 	// strip out inappropriate cartridges
 	target->media.cartridges = AcornCartridgesFrom(media.cartridges);
@@ -111,9 +107,10 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 		if(dfs_catalogue == nullptr) adfs_catalogue = GetADFSCatalogue(disk);
 		if(dfs_catalogue || adfs_catalogue) {
 			// Accept the disk and determine whether DFS or ADFS ROMs are implied.
+			// Use the Pres ADFS if using an ADFS, as it leaves Page at &EOO.
 			target->media.disks = media.disks;
 			target->has_dfs = bool(dfs_catalogue);
-			target->has_adfs = bool(adfs_catalogue);
+			target->has_pres_adfs = bool(adfs_catalogue);
 
 			// Check whether a simple shift+break will do for loading this disk.
 			Catalogue::BootOption bootOption = (dfs_catalogue ?: adfs_catalogue)->bootOption;
@@ -144,6 +141,13 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 		}
 	}
 
+	// Enable the Acorn ADFS if a mass-storage device is attached;
+	// unlike the Pres ADFS it retains SCSI logic.
+	if(!media.mass_storage_devices.empty()) {
+		target->has_pres_adfs = false;
+		target->has_acorn_adfs = true;
+	}
+
 	TargetList targets;
 	if(!target->media.empty()) {
 		targets.push_back(std::move(target));

Analyser/Static/Acorn/Target.hpp

@@ -18,7 +18,8 @@ namespace Static {
 namespace Acorn {
 
 struct Target: public ::Analyser::Static::Target, public Reflection::StructImpl<Target> {
-	bool has_adfs = false;
+	bool has_acorn_adfs = false;
+	bool has_pres_adfs = false;
 	bool has_dfs = false;
 	bool has_ap6_rom = false;
 	bool has_sideways_ram = false;
@@ -27,7 +28,8 @@ struct Target: public ::Analyser::Static::Target, public Reflection::StructImpl<
 
 	Target() : Analyser::Static::Target(Machine::Electron) {
 		if(needs_declare()) {
-			DeclareField(has_adfs);
+			DeclareField(has_pres_adfs);
+			DeclareField(has_acorn_adfs);
 			DeclareField(has_dfs);
 			DeclareField(has_ap6_rom);
 			DeclareField(has_sideways_ram);

Machines/Electron/Electron.cpp

@@ -64,10 +64,15 @@ class ConcreteMachine:
 				{machine_name, "the Acorn BASIC II ROM", "basic.rom", 16*1024, 0x79434781},
 				{machine_name, "the Electron MOS ROM", "os.rom", 16*1024, 0xbf63fb1f}
 			};
-			if(target.has_adfs) {
+			const size_t pres_adfs_rom_position = required_roms.size();
+			if(target.has_pres_adfs) {
 				required_roms.emplace_back(machine_name, "the E00 ADFS ROM, first slot", "ADFS-E00_1.rom", 16*1024, 0x51523993);
 				required_roms.emplace_back(machine_name, "the E00 ADFS ROM, second slot", "ADFS-E00_2.rom", 16*1024, 0x8d17de0e);
 			}
+			const size_t acorn_adfs_rom_position = required_roms.size();
+			if(target.has_acorn_adfs) {
+				required_roms.emplace_back(machine_name, "the Acorn ADFS ROM", "adfs.rom", 16*1024, 0x3289bdc6);
+			}
 			const size_t dfs_rom_position = required_roms.size();
 			if(target.has_dfs) {
 				required_roms.emplace_back(machine_name, "the 1770 DFS ROM", "DFS-1770-2.20.rom", 16*1024, 0xf3dc9bc5);
@@ -91,19 +96,23 @@ class ConcreteMachine:
 
 					* the keyboard and BASIC ROMs occupy slots 8, 9, 10 and 11;
 					* the DFS, if in use, occupies slot 1;
-					* the ADFS, if in use, occupies slots 4 and 5;
+					* the Pres ADFS, if in use, occupies slots 4 and 5;
+					* the Acorn ADFS, if in use, occupies slot 6;
 					* the AP6, if in use, occupies slot 15; and
 					* if sideways RAM was asked for, all otherwise unused slots are populated with sideways RAM.
 			*/
-			if(target.has_dfs || target.has_adfs) {
+			if(target.has_dfs || target.has_acorn_adfs || target.has_pres_adfs) {
 				plus3_ = std::make_unique<Plus3>();
 
 				if(target.has_dfs) {
 					set_rom(ROM::Slot0, *roms[dfs_rom_position], true);
 				}
-				if(target.has_adfs) {
+				if(target.has_pres_adfs) {
-					set_rom(ROM::Slot4, *roms[2], true);
+					set_rom(ROM::Slot4, *roms[pres_adfs_rom_position], true);
-					set_rom(ROM::Slot5, *roms[3], true);
+					set_rom(ROM::Slot5, *roms[pres_adfs_rom_position+1], true);
+				}
+				if(target.has_acorn_adfs) {
+					set_rom(ROM::Slot6, *roms[acorn_adfs_rom_position], true);
 				}
 			}
 
@@ -298,6 +307,7 @@ class ConcreteMachine:
 					break;
 
 					case 0xfc04: case 0xfc05: case 0xfc06: case 0xfc07:
+						printf("%04x %s %02x\n", address, isReadOperation(operation) ? "->" : "<-", *value);
 						if(plus3_ && (address&0x00f0) == 0x00c0) {
 							if(is_holding_shift_ && address == 0xfcc4) {
 								is_holding_shift_ = false;
@@ -310,12 +320,39 @@ class ConcreteMachine:
 						}
 					break;
 					case 0xfc00:
+						printf("%04x %s %02x\n", address, isReadOperation(operation) ? "->" : "<-", *value);
 						if(plus3_ && (address&0x00f0) == 0x00c0) {
 							if(!isReadOperation(operation)) {
 								plus3_->set_control_register(*value);
 							} else *value = 1;
 						}
 					break;
+					case 0xfc03:
+						printf("%04x %s %02x\n", address, isReadOperation(operation) ? "->" : "<-", *value);
+					break;
+
+					// SCSI locations:
+					//
+					//	fc40:	data, read and write
+					//	fc41:	status read
+					//	fc42:	select write
+					//	fc43:	interrupt latch
+					//
+					// Status byte is:
+					//
+					//	b7:	SCSI C/D
+					//	b6: SCSI I/O
+					//	b5: SCSI REQ
+					//	b4: interrupt flag
+					//	b3:	0
+					//	b2:	0
+					//	b1:	SCSI BSY
+					//	b0: SCSI MSG
+					//
+					// Interrupt latch is:
+					//
+					//	b0: enable or disable IRQ on REQ
+					//	(and, possibly, writing to the latch acknowledges?)
 
 					default:
 						if(address >= 0xc000) {

OSBindings/Mac/Clock Signal/Machine/StaticAnalyser/CSStaticAnalyser.mm

@@ -99,7 +99,7 @@
 		using Target = Analyser::Static::Acorn::Target;
 		auto target = std::make_unique<Target>();
 		target->has_dfs = dfs;
-		target->has_adfs = adfs;
+		target->has_pres_adfs = adfs;
 		target->has_ap6_rom = ap6;
 		target->has_sideways_ram = sidewaysRAM;
 		_targets.push_back(std::move(target));

ROMImages/Electron/readme.txt

@@ -8,10 +8,9 @@ DFS-1770-2.20.rom	— used only if the user opens a DFS disk image
 ADFS-E00_1.rom		— used only if the user opens an ADFS disk image
 ADFS-E00_2.rom
 AP6v133.rom			— used only if the user opens a disk image that makes use of any of the commands given below.
+adfs.rom			- used only if the user opens a hard disk image
 
 Possibly to be desired in the future:
-* adfs.rom
-* ElectronExpansionRomPresAP2-v1.23.rom
 * os300.rom
 
 Commands that trigger a request for the AP6v133 ROM: