Porting NES games to the 2600

I gave up on NES programming. It's too hard. So instead what I'm going to do is try to port NES games to the 2600. Since the only drawing program on the VCS is Stell-a-Sketch, I'm trying my hand at porting Videomation to the 2600. Basically what Videomation is is Mario Paint for the NES. After a few hours of tinkering, I got the music for the title screen working. It's the same song as the NES version, but in a different key. Once you press fire, you can draw. Move the marker with the joystick and press fire to put the marker to the paper. Pressing the reset switch erases your picture. But I have a little problem. The only diagonal direction you can use is up+right, and I'm wondering why that is, so if any bB users can take a look at my code and see what the heck I'm doing wrong here, I'd very much appreciate it. I've also attached the binary so you can see what I'm talking about. Up next for this project is being able to change colors with the select switch, and also sfx for the drawing part (you'd have to play Videomation for the NES to know what I'm talking about.) By the way, I'll be working on Violent Violet as well, as soon as someone can design me some sprites. I wonder why both video games I'm working on start with the unusual letter V.