The Electric Monk

Yes, it's a display bug in Stella. The bug was reported in another thread, and will hopefully go away when the TIA emulation is rewritten. Wow, that's good to know. That had been driving me nuts! I knew it was an HMOVE 'thing', because I replaced the STA HMOVE instruction with a STA to another, unused, register and the black line went away. I thought perhaps I had a timing problem or was setting up the horizontal move wrong, but now I won't bother posting my code here. Thanks for pointing that out. Cheers, Jason

Out of curiosity, does 'split-up kernels' mean that different kernels are drawn for different frames? For example, Frame 1: Draw top of screen, Frame 2: Draw middle of screen, Frame 3: Draw bottom of screen, Frame 4: Draw top of screen again, etc.? If so, how many splits can you have before you start getting screen flicker?

Legal, yes. It's actually address $D20A - which is a mirror for romspace. If used on the 2600, you would be reading an unchanging value (unless something other than native hardware is involved - i.e. Supercharger, etc). So it would not be applicable to this discussion. The address is a random number generator in the Atari computer line. Your second part is valid, so long as the 7800 isn't being used to play the game (this powers up with known values in Ram...making it possible to "autodetect" if that console is being used vs. the 2600 or emulators). Belated thanks, Nukey. That makes sense.

Is 'LDA 53770' legal in 6502 for the 2600? All the random number algorithms I've seen before take advantage (I think) of the fact that the 2600 powers up in a random state, so the contents of any memory address can serve as a seed for an LFSR (it's called something like that) algorithm. This seems much easier if it's kosher. Thanks, Jason