Is this an insight to a scanline problem?

[yuppicide]

Awhile ago I was chatting about a game I have with scanline issues. The game draws a border on both sides, and a line scrolling down the screen. When the line reaches the bottom of the screen is where the scanline issue comes into play. Otherwise it's a constant 262. I have a thread open here with the code:

 

http://www.atariage.com/forums/topic/155629-blocked-in/page__p__1908030__hl__blocked%20in__fromsearch__1#entry1908030

 

.. as you can see the sides of my border are colored. I noticed something on the bB Command Page and discussed it with RT that I didn't understand how to make the borders black.. he updated his page:

 

http://www.randomterrain.com/atari-2600-memories-batari-basic-commands.html#pf0

 

.. and I put it in my game.. now watch the video I've attached here.. sorry for low quality.. I wanted to get it to upload here without going through YouTube..

 

Do you think that video with the border flicker / scanline issue provides any additional insight as to what I should look for and where I should try and correct the problem? I've been going over and over possible solutions and code rewrite for awhile now

blocked_in.wmv

[Nukey Shay]

Regarding the border, PF0 draws 4 pixels (selected in the upper nybble of the value). Because your playfield color is black, giving PF0 a value of #$F0 (bitpattern %11110000) turns on all of the pixels and effectively masks (covers up) the background blue color. This trick could also be used to hide player sprites as they move on or off the screen from the side, or to hide HMOVE lines if the display is repositioning sprites during execution.

 

The scanline count problem would be better solved by looking at the program itself rather than a video of it. It's probably as simple as running out of time out of the display. Have you tried adding an additional drawscreen someplace in your program?