I've ironed out 99% of what I found wrong with the display since version 0.014. There's no more stretching at the top of the screen, an object of coordinate Y can now be positioned in exactly the same place regardless of if P0 or P1 is displaying it. (noticable when you pick up a heart when the key is in the same room. )

 

While not intended, in the rom so far the heart always ends up being slotted in P0. The key will display with P0 if the heart isn't on the screen. If the heart is present the key gets shoved into P1. The way to notice this is that the player always takes the color of P1. P1 is defaulted to blue if it is not currently displaying an object.

 

Anyway, I seem to have most of the glitches fixed. The only remaining glitch is again with the top of the screen but it's an identical problem with both P1 and P0. An object appears to display the wrong sprite data in the top two scanlines. At least it doesn't stretch like it use to.

 

Too tired to fix that right now. 5am. Going to bed. (I work nights, so I'm not as mal-adjusted for sleep as it would appear. )

 

I haven't looked at how objects act at the bottom of the screen yet. I think they display normally but knowing my luck they won't be quite good enough. I'll worry about that after the top of the screen is completely fixed.

 

After both sides of the screen are fixed I'll try to modify the heart-placer routine to fill up the object slots and essentially throw hearts around the test realm. There will still be a key tho. And that will be the release of Version 0.015.

 

*update*

 

After a bit of observeration and testing when I woke up this morning, I've determined where the faulty info is being drawn from for the top two scanlines on the gamefield area portion of the display. The incorrect data for the sprites that go up to those two scanlines (and it's consistant with both P0 and P1) is the wrong byte of data being drawn in on those scanlines. Instead of taking the top data byte it's taking the byte next to it - which happens to be the sprite's color.

 

Don't have a lot of time today to do comprehensive studiez on it to write a fix but I'll see what I can do when I get home.