rust-6502-emu

My Rust learning project writing a simple 6502 emulator.

⚠️ Although there are some unit tests, the functionality is not yet completely tested or proven. And some functionality such as BCD mode still needs to be implemented. This is just a tinkering project - don't expect too much!

Key data:

• Memory size: 64K
• Stack: 0x0100 to 0x01FF
• Reset vector address: 0xE000

Building

cargo build --release

This results in the release binary ./target/release/rust-6502-emu.

Running

Synopsis

Usage: rust-6502-emu [OPTIONS]

Options:
  -c, --cycles <CYCLES>  Cycles to execute
  -d, --demo             Load demo data
  -f, --file <FILE>      Load data from file
  -i, --interactive      Interactive mode
  -v, --verbose...       Verbosity; can be specified multiple times
  -h, --help             Print help
  -V, --version          Print version

Example invocation

Running an example program:

./target/release/rust-6502-emu -f examples/fibonacci.bin

Running an example program step-by-step in interactive mode:

./target/release/rust-6502-emu -i -f examples/fibonacci.bin

Running with demo code:

./target/release/rust-6502-emu -d

Running without a program initialized in memory is less exciting, as we're hitting a BRK as first instruction:

./target/release/rust-6502-emu

Example programs

There are some example programs in ./examples including a Makefile. CC65 is used for assembling and linking.

Pre-built *.bin files can be loaded using the -f <binfile> option.

The examples can be (re)build using make all.

Useful resources / documents

• https://en.wikipedia.org/wiki/MOS_Technology_6502
• https://www.masswerk.at/6502/6502_instruction_set.html
• https://web.archive.org/web/20190925014923/http://www.obelisk.me.uk/6502/
  • https://web.archive.org/web/20190926210651/http://www.obelisk.me.uk/6502/reference.html
  • https://web.archive.org/web/20190908035706/http://www.obelisk.me.uk/6502/addressing.html
• https://sta.c64.org/cbm64mem.html
• https://www.nesdev.org/wiki/Status_flags
• https://www.pagetable.com/?p=410
• https://en.wikibooks.org/wiki/6502_Assembly
• https://codeburst.io/running-programs-on-the-apple-ii-cc183aab268
• https://en.wikipedia.org/wiki/Interrupts_in_65xx_processors
• Testing
  • https://www.nesdev.org/wiki/Visual6502wiki/6502TestPrograms
  • https://github.com/Klaus2m5/6502_65C02_functional_tests

Tools

• https://www.masswerk.at/6502/
• https://cc65.github.io/