Kiwi 6502 emulator

This is another 6502 emulator written in C. The goal for this one was learning how to write one, and hopefully use it to emulate a complete system like the NES sometime. There are a few pending things and more tests required, which will be done soon.

Compiling

It has been tested on linux with gcc, but should work elsewhere.

To compile, just run make.

$ make
gcc -Wall -Wextra -Wno-unused-parameter -O0 -ggdb -I. kiwi.c instructions.c main.c -o kiwi

Running

Once compiled, run as ./kiwi 6502_functional_test.bin or make run to run a functional test of the CPU. The PC will loop on 0x056D, which means the supplied tests have passed.

Notes on main.c

The demo program main.c connects two things to the 6502 CPU:

1. RAM from 0x0000 to 0x01FF, i.e. two pages (page is 0xFF bytes), which is mandatory, and required by the test program.
2. ROM containing the test program from 0x0400 till the 0xFFFF.

We actually copy contents of the test program from 0x0000 to 0x01ff to RAM also.

ROM is a added using mmap() and RAM is a uint8_t array in the code.

There are no I/O ports or interrupts, and as mentioned above, the tests have passed when the CPU is looping on PC. The current test binary fails test cases related to that.