In this topic about the exciting new RGB mod for the 2600, collinp reported that the XRGB-mini had problems syncing with Warlords.
I took a quick look and noticed that VSYNC was set before the WSYNC, instead of after, which resulted in the sync signal starting late in the scanline.
I did a quick hack via Stella to swap the order. The hack resulted in the kings getting shifted to the right, but was enough for collinp to confirm that moving the VSYNC after the WSYNC did indeed fix the probl
I'm down to 8 RAM variables to decipher and have 108 labels renamed1 with 214 to go. A couple interesting finds:
each player's paddle is only read every 4th frame. There's a couple subroutines, that I named SmoothXmotion and SmoothYmotion, that are used to smooth out the motion over the 4 frames between paddle readings. As a test I changed subroutine to NOP the smoothing and the motion was very jerky.
Paddle usage had me confused for a little bit:
During the Vertical Blank the program converts the paddle reading to x-y sprite coordinates as well as setting the X sprite position of the top players and calculating the X positioning values for the bottom players. However, the sequence isn't in the correct order. It's not a major deal, unless you have captured a fireball. If you're holding a fireball then you run the risk of killing yourself even if you've not lost a single brick!The program does the following:
1) Positions the X position o
I'm working on enhancing Warlords for the 2600. I plan to convert it to 8K then start hacking away. I'm currently on step 1 and have attached the source with my first weeks worth of commenting in case anybody would like to review it.
1) Document Source
2) Convert to 8K
3) find RAM for new routines (rewrite of wall routines should free up 32 bytes)
4) Hack away - changes in no specific order:
The Launch Dragon
More angles on the fireball