Goog,

I don't want to dampen your enthusiasm for writing yet another 6502 simulator, but there are lots of them already out there. The source code for Kowalski's is on his web site.

I'm not aware of there being one of the same quality of Kowalski's for the 65802/65816 instruction set. There are ...

The most interesting one I found was by Wolfgang Lorenz. He wrote a C64 emulator some time ago. If you google for something like "wolfgang lorenz 6502 test suite" you should be able to track down his testsuite-2.1x.tar.gz code.

It needs work to make it run on Kowalski's emulator as it uses C64 bios ...

Michal Kowalski's 6502 simulator gets the high byte from $0000

It looks like it does when you watch the 'Arg' field in the 'uP Registers and Stack' window. However, have a look at the value of the accumulator after the operation is performed.

Here's my test code:

.ORG $00
.DB $20
.ORG $ff ...

Please can you explain how the following 65C02 opcode works:

LDA ($FF)

My understanding is that the effective address (EA) low-byte will come from $00FF and the EA high-byte from $0000. All the software simulators I've tested indicate that the EA high-byte comes from $0100. Are the simulators ...

I'd appreciate your combined experiences on the following:
CLI
LDX #$00
INX


Assume that interrupts are disabled and the IRQ\ line has gone low before the CLI op-code. I'm trying to figure out if the LDX op-code gets performed before the IRQ interrupt service routine gets called. My experiments ...

My work project requires the use of a 65(C)02 'C' compiler. I've tried the IAR and Avocet demos. I like the AVR's IDE and its debugger (supports inline ASM code listing). I'm concerned that its not being kept up to-date as the documentation is dated 1997 and the last updates to it were made in 2001 ...

Can any of you 65(C)02 emulator/simulator writers out there point me in the direction of some well-established code that will allow me to test out all the standard op-codes? Presumably, you must have tested your emulator/simulator on such code?

I'd like to obtain a dump of of the PC and A,X,Y,P,S ...