The simulator now passes Klaus Dormann's 6502 Functional Test suite for
the first time.
Bug Fixes:
- PHP was not correctly setting the Break bit on the stack copy of the
processor status, so subsequent PLA's would not set the Break status
flag.
- The CPU had swapped NMI and IRQ reset vectors, so RTI was failing.
- BRK was pushing PC + 2 onto the stack, instead of PC + 1
- (Zero Page,X) addressing mode did not correctly wrap on zero page
boundaries.
- The instruction table used for disassembly had addressing modes
of LDA $B9 and $BD reversed. This did not affect behavior, only
disassembly of these instructions.
Other:
- Updated copyright date for 2013.
- Started migrating old JUnit 3 style tests to JUnit 4 annotations.
Bug Fixes:
- Fixed several bugs in the CPU that caused processor status flags to
be set incorrectly. Instructions affected were: STA, STX, STY, CMP,
CPX, CPY, BIT.
- Made some internal-use-only methods on the CPU class private.
- Fixed incorrect disassembly of (Indirect,X) and (Indirect),Y
instructions. Although this didn't affect behavior, it certainly
caused me some confusion in debugging.
- Added missing "BCS" instruction to instruction table.
Enhancements:
- Now includes a full version of Lee Davison's Enhanced 6502 BASIC
bundled as source code and a ROM image. Get that REAL COMPUTER
EXPERIENCE!(tm)
- If a file named "rom.bin" exists in the same directory where the
simulator is executed, it will be loaded at addresses $d000-$ffff.
- Gave the CPU an idle loop to make simulated timing a little more
realistic (but this is still an area needing major improvement)
- Changed the CPU's toString() method to give better debugging output.
- Added a small typeahead buffer to the Console.
- Better exception messaging.
Misc:
- Bumped version to 0.5, updated README.
MOS6551 ACIA at address $C000 which does buffered input and output via the
console. Updated the README with a bit more documentation, and bumped the
version number to 0.1 because I'm impatient.
- Removed the CommandParser class entirely, as the weird dependency between
Simulator and CommandParser never made me comfortable.
- Added a Command inner class to Simulator that handles some of the
command line tokenizing.
