CHESS: The Budapest Gambit

I had been studying The Budapest Gambit via Bogdan Lalić's late 90's ebook described by the Amazon bookstore as "a relatively rare but sound attempt by Black to disrupt White's smooth development and this book provides up-to-date coverage of this sharp opening, ever-popular at club level". With the Black pieces against OS X's Chess program I played this opening but was surprised when White played 4.Qd4 which does not appear in any of the main lines covered in the book. However, there is a reference to this move in Games 73 and 74:

The book suggests that the best continuation for Black is 4...d6 which is what I played in my game. After which, play proceeds as 5.exd6 Bxd6 after which White plays 6.Nf3 in Game 74 and 6.Q4+ in Game 73. In my game, White played the former and play continued thus:

This led to the following position after Black's 19th move:

My position, I thought, was pretty solid but then White made a completely unexpected move, viz. 20.Nd5 cutting off my black-squared Bishop from the support of the Rooks.

I first tried 20...Bxf2+ but that doesn't work out so well. In the end I settled on 20...cxd5 which led to a drawn position although the program didn't concede a draw. Instead it just kept playing. Below is the situation after a seemingly interminable 169 moves, snapped from my perspective playing with the Black pieces (note HGFEDCBA file order from left to right):

I won't put down all the 169 moves but these moves (up to move 53 show where things are headed):

The chess program in OS X has a glitch whereby it crashes whenever I attempt to save the game in PGN format. It would be nice to learn how to embed a game with controls as they do on most of the online chess sites. I must investigate how to do this, otherwise my blog posts are rather limited.