Furthered fleshing out of the 1540. Though it doesn't yet receive a ROM so won't even attempt to do anything meaningful.

Machines/Commodore/1540/Commodore1540.cpp

@@ -7,3 +7,29 @@
 //
 
 #include "Commodore1540.hpp"
+#include <string.h>
+
+using namespace Commodore::C1540;
+
+unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
+{
+	if(address < 0x800)
+	{
+		if(isReadOperation(operation))
+			*value = _ram[address];
+		else
+			_ram[address] = *value;
+	}
+	else if(address >= 0xc000)
+	{
+		if(isReadOperation(operation))
+			*value = _rom[address & 0x3fff];
+	}
+
+	return 1;
+}
+
+void Machine::set_rom(uint8_t *rom)
+{
+	memcpy(_rom, rom, sizeof(_rom));
+}

Machines/Commodore/1540/Commodore1540.hpp

@@ -9,6 +9,26 @@
 #ifndef Commodore1540_hpp
 #define Commodore1540_hpp
 
-#include <stdio.h>
+#include "../../../Processors/6502/CPU6502.hpp"
+#include "../../../Components/6522/6522.hpp"
+
+namespace Commodore {
+namespace C1540 {
+
+class Machine:
+	public CPU6502::Processor<Machine> {
+
+	public:
+		unsigned int perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value);
+
+		void set_rom(uint8_t *rom);
+
+	private:
+		uint8_t _ram[0x800];
+		uint8_t _rom[0x4000];
+};
+
+}
+}
 
 #endif /* Commodore1540_hpp */

Machines/Commodore/Vic-20/Vic20.cpp

@@ -54,6 +54,9 @@ Machine::Machine() :
 	write_to_map(_processorWriteMemoryMap, _userBASICMemory, 0x0000, sizeof(_userBASICMemory));
 	write_to_map(_processorWriteMemoryMap, _screenMemory, 0x1000, sizeof(_screenMemory));
 	write_to_map(_processorWriteMemoryMap, _colorMemory, 0x9400, sizeof(_colorMemory));
+
+	// TEMPORARY: attach a [diskless] 1540
+	set_disc();
 }
 
 void Machine::write_to_map(uint8_t **map, uint8_t *area, uint16_t address, uint16_t length)
@@ -121,6 +124,7 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
 	_keyboardVIA->run_for_half_cycles(2);
 	if(_typer) _typer->update(1);
 	_tape.run_for_cycles(1);
+	if(_c1540) _c1540->run_for_cycles(1);
 	return 1;
 }
 
@@ -150,9 +154,11 @@ void Machine::set_rom(ROMSlot slot, size_t length, const uint8_t *data)
 	size_t max_length = 0x2000;
 	switch(slot)
 	{
-		case ROMSlotKernel:		target = _kernelROM;							break;
-		case ROMSlotCharacters:	target = _characterROM;	max_length = 0x1000;	break;
-		case ROMSlotBASIC:		target = _basicROM;								break;
+		case Kernel:		target = _kernelROM;							break;
+		case Characters:	target = _characterROM;	max_length = 0x1000;	break;
+		case BASIC:			target = _basicROM;								break;
+		case Drive:
+		return;
 	}
 
 	if(target)
@@ -323,3 +329,10 @@ void Tape::process_input_pulse(Storage::Tape::Pulse pulse)
 		if(_delegate) _delegate->tape_did_change_input(this);
 	}
 }
+
+#pragma mark - Disc
+
+void Machine::set_disc()
+{
+	_c1540.reset(new ::Commodore::C1540::Machine);
+}

Machines/Commodore/Vic-20/Vic20.hpp

@@ -13,6 +13,7 @@
 #include "../../../Storage/Tape/Tape.hpp"
 #include "../../../Components/6560/6560.hpp"
 #include "../../../Components/6522/6522.hpp"
+#include "../1540/Commodore1540.hpp"
 #include "../SerialBus.hpp"
 
 #include "../../CRTMachine.hpp"
@@ -22,9 +23,10 @@ namespace Commodore {
 namespace Vic20 {
 
 enum ROMSlot {
-	ROMSlotKernel,
-	ROMSlotBASIC,
-	ROMSlotCharacters,
+	Kernel,
+	BASIC,
+	Characters,
+	Drive
 };
 
 #define key(line, mask) (((mask) << 3) | (line))
@@ -235,6 +237,7 @@ class Machine:
 		void set_rom(ROMSlot slot, size_t length, const uint8_t *data);
 		void add_prg(size_t length, const uint8_t *data);
 		void set_tape(std::shared_ptr<Storage::Tape> tape);
+		void set_disc();
 
 		void set_key_state(Key key, bool isPressed) { _keyboardVIA->set_key_state(key, isPressed); }
 		void clear_all_keys() { _keyboardVIA->clear_all_keys(); }
@@ -296,6 +299,9 @@ class Machine:
 		// Tape
 		Tape _tape;
 		bool _use_fast_tape_hack;
+
+		// Disc
+		std::shared_ptr<::Commodore::C1540::Machine> _c1540;
 };
 
 }

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSVic20.h

@@ -15,6 +15,7 @@
 - (void)setKernelROM:(nonnull NSData *)rom;
 - (void)setBASICROM:(nonnull NSData *)rom;
 - (void)setCharactersROM:(nonnull NSData *)rom;
+- (void)setDriveROM:(nonnull NSData *)rom;
 
 - (void)setPRG:(nonnull NSData *)prg;
 - (BOOL)openTAPAtURL:(nonnull NSURL *)URL;

OSBindings/Mac/Clock Signal/Machine/Wrappers/CSVic20.mm

@@ -29,15 +29,19 @@ using namespace Commodore::Vic20;
 }
 
 - (void)setKernelROM:(nonnull NSData *)rom {
-	[self setROM:rom slot:ROMSlotKernel];
+	[self setROM:rom slot:Kernel];
 }
 
 - (void)setBASICROM:(nonnull NSData *)rom {
-	[self setROM:rom slot:ROMSlotBASIC];
+	[self setROM:rom slot:BASIC];
 }
 
 - (void)setCharactersROM:(nonnull NSData *)rom {
-	[self setROM:rom slot:ROMSlotCharacters];
+	[self setROM:rom slot:Characters];
+}
+
+- (void)setDriveROM:(nonnull NSData *)rom {
+	[self setROM:rom slot:Drive];
 }
 
 - (BOOL)openTAPAtURL:(NSURL *)URL {

ROMImages/Commodore1540/readme.txt

@@ -0,0 +1,5 @@
+ROM files would ordinarily go here; the copyright status of these is uncertain so they have not been included in this repository.
+
+Expected files:
+
+1540.rom; a 16kb image of the 1540's ROM area.