General Information

The emulator requires Python 3.10 or later. The assembly written in this repository requires dasm because it's the easiest one I could find to install on my laptop when I started this project.

Current Progress

Addressing

Done	Tests	Addressing Mode	Comments
✔️	✔️	Implied
✔️	✔️	Accumulator	Handled via direct access to A
✔️	✔️	Immediate	Implemented via _a_immediate()
✔️	✔️	Absolute	Implemented via _a_absolute()
✔️	✔️	X-Indexed Absolute	Implemented via _a_indexed_absolute('X')
✔️	✔️	Y-Indexed Absolute	Implemented via _a_indexed_absolute('Y')
✔️		Indirect	Implemented via _a_indirect()
✔️	✔️	Zero Page	Implemented via _a_zero_page()
✔️	✔️	X-Indexed Zero Page	Implemented via _a_zero_page_indexed('X')
✔️	✔️	Y-Indexed Zero Page	Implemented via _a_zero_page_indexed('Y')
✔️	✔️	X-Indexed Zero Page Indirect	Implemented via _a_x_indexed_zp_indirect()
✔️	✔️	Zero Page Indirect Y-Indexed	Implemented via _a_zp_indirect_y_indexed()

Bus

The bus is built, but I need to clean it up a bit and document how you attach things to it. For now, you can create custom BusObjects and attach them to the main bus. There are also two pre-created BusObjects: RAM (BusRam) and ROM (BusRom). Also, you can attach the same object to the bus at a different location by setting the mirror option to True when attaching it to the bus.

Stack

Done	Feature	Comment
✔️	Stack	Completed
✔️	Stack Pointer	Completed

Done	Method	Comment
✔️	_s_push_byte(value: int)	Pushes a byte value onto the stack and increments the stack pointer.
✔️	_s_push_address(address: int)	Pushes an address onto the stack and increments the stack pointer twice.
✔️	_s_pop_byte()	Pulls a byte from the stack and decrements the stack pointer.
✔️	_s_pop_address()	Pulls an address from the stack and decrements the stack pointer twice.

Instructions

Documented

Done	Tests	Instruction	# of Opcodes	Comment
✔️	✔️	ADC	8	Completed (including decimal mode)
✔️	✔️	AND	8	Completed
✔️	✔️	ASL	5	Completed
✔️	✔️	BCC	1	Completed
✔️	✔️	BCS	1	Completed
✔️	✔️	BEQ	1	Completed
✔️	✔️	BMI	1	Completed
✔️	✔️	BNE	1	Completed
✔️	✔️	BPL	1	Completed
✔️	✔️	BVC	1	Completed
✔️	✔️	BVS	1	Completed
✔️	✔️	BIT	2	Completed
✔️		BRK	1	Completed
✔️	✔️	CLC	1	Completed
✔️	✔️	CLD	1	Completed
✔️	✔️	CLI	1	Completed
✔️	✔️	CLV	1	Completed
✔️	✔️	CMP	8	Completed
✔️	✔️	CPX	2	Completed
✔️	✔️	CPY	2	Completed
✔️	✔️	DEC	4	Completed
✔️	✔️	DEX	1	Completed
✔️	✔️	DEY	1	Completed
✔️	✔️	EOR	8	Completed
✔️	✔️	INC	4	Completed
✔️	✔️	INX	1	Completed
✔️	✔️	INY	1	Completed
✔️	✔️	JMP	2	Completed
✔️		JSR	1	Completed
✔️	✔️	LDA	8	Completed
✔️	✔️	LDX	5	Completed
✔️	✔️	LDY	5	Completed
✔️	✔️	LSR	5	Completed
✔️	✔️	NOP	1	Completed
✔️	✔️	ORA	8	Completed
✔️	✔️	PHA	1	Completed
✔️	✔️	PHP	1	Completed
✔️	✔️	PLA	1	Completed
✔️	✔️	PLP	1	Completed
✔️	✔️	ROL	5	Completed
✔️	✔️	ROR	5	Completed
✔️		RTI	1	Completed
✔️		RTS	1	Completed
✔️	✔️	SBC	8	Completed (including decimal mode)
✔️	✔️	SEC	1	Completed
✔️	✔️	SED	1	Completed
✔️	✔️	SEI	1	Completed
✔️	✔️	STA	7	Completed
✔️	✔️	STX	3	Completed
✔️	✔️	STY	3	Completed
✔️	✔️	TAX	1	Completed
✔️	✔️	TAY	1	Completed
✔️	✔️	TSX	1	Completed
✔️	✔️	TXA	1	Completed
✔️	✔️	TXS	1	Completed
✔️	✔️	TYA	1	Completed

Undocumented

Done	Tests	Instruction	# of Opcodes	Comment
✔️		ANC	7	Completed
✔️		ARR	1	Completed (including decimal mode)
✔️		ASR	1	Completed
✔️		DCP	7	Completed
✔️		ISB	7	Completed (including decimal mode)
✔️		LAS	1	Completed
✔️		LAX	6	Completed
✔️		NOP	27	Completed
✔️		RLA	7	Completed
✔️		RRA	7	Completed (including decimal mode)
✔️		SAX	4	Completed
✔️		SBX	1	Completed
✔️		SLO	7	Completed
✔️		SRE	7	Completed

Testing

The project uses pytest to run through all of the tests in the tests directory. This is currently the sole external dependency of the project, and can be installed poetry install.

To run all of the tests, simply run pytest at the root of the repository.