There's something a bit special about debugging your new emulator by using the debugging facilities in an existing emulator! (But a demonstration of the power of using watchpoints and trace comparisons. One must always be alert to the possibility that the reference emulator has bugs too.)

An interesting episode, all the same. Thanks for keeping up the blogging.

Thanks BigEd!

Yes, I fully agree, the bugs of a reference emulator can easily cause you to chase your own tail

What I think could be a real challenge would be to use a real C64 for a reference implementation for debugging an emulator.

I have just released the final part of series on writing an emulator from scratch in JavaScript. With this version of the emulator you can now fully play the game Dan Dare.

Here is the link:

http://emufromscratch.blogspot.com/2016 ... rites.html

Very good - a tour de force! You never gave up, which is quite something given the challenge.