Search found 485 matches

by infidelity
Tue Jun 22, 2021 6:17 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Having a very difficult time keeping my hdma irq split functional, while horizontally scrolling. When I enter a room where the upper half of the screen needs to move up and down, it does it. But soon after when I'm moving and sprites appear, the hdma split starts to spread apart? I got myself to a p...
by infidelity
Mon Jun 21, 2021 6:00 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Idk. However, I've now just figured out the equations for going down! :-D just finished tightening up the code. I'm at work now, but will write out exactly what it all is. :-) update when an irq split screen is activated that moves up & down, the gap between screens is still present, will need to fi...
by infidelity
Mon Jun 21, 2021 4:19 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Are you sure it was the top portion that was off? That seems very weird. Keep in mind that "neutral" vscroll on SNES is -1 because of the blank line 0. From my observation yes, it was the top that was the issue when I came to needing to alter the table, after 7F has been read for # of scanlines. Wh...
by infidelity
Sun Jun 20, 2021 6:03 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Excellent! I figured there was probably some way to rig the table to get away with a minimum of rewriting, but I decided not to complicate things... anyway, it's good to hear you got it working. One question - why does the initial scroll value ($7E:8001) get decremented? Is that just the normal scr...
by infidelity
Sun Jun 20, 2021 4:39 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

you don't have to go from the top of the screen to the split in one leap - you can wait some number of lines less than 128, write the same top-of-screen scroll value over again (which does nothing to the display), and then wait the rest of the interval and write the split value. It extends the tabl...
by infidelity
Sun Jun 20, 2021 1:56 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Can edit specific registers during h-blank
by infidelity
Sun Jun 20, 2021 1:25 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

this nes game has the screens side by side when accessing a vertical porition of the stage. You say make the table bigger, but i'm confused as to how i'm supposed to keep doing what i'm doing, once i reach 7F in my first byte? I've been altering bytes on the fly to try to see a difference but i cant...
by infidelity
Sun Jun 20, 2021 9:49 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

You are correct, 94143. I guess what I wrote was way off. I ran some tests, just to confirm. Once you enable HDMA, it runs every frame and resets the table automatically, just before drawing the first scanline. The first value in the table is transferred before the wait (not after), and affects eve...
by infidelity
Sun Jun 20, 2021 5:17 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Everything honestly. The only thing I have working, is the prep work for the hdma in regards to where to load the hdma table. Im going to have my table located at 7E:8000. I dont know how big the table is supposed to be either. I work better with visual aids, step by step. I've tried searching the i...
by infidelity
Sat Jun 19, 2021 5:04 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

I'm sorry I'm new to hdma and its just confusing to me. I'm going to hold off and move on with the port.
by infidelity
Sat Jun 19, 2021 3:10 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Also, why are you loading a value and branching on it, only to load it again at the branch target? Can't you assume that you arrive at LDA $FA with the value already in the accumulator? I'm just testing, trying different things, this wont be in the final code I use. So should I stick with using rom...
by infidelity
Sat Jun 19, 2021 1:09 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Very complicated. Tried watching a video on it. I've actually got my table loaded in rom, but I have no clue what I'm doing, I'm just blindly editing my table on the fly to watch the different actions. Right now I have it so $420C is only active during a vertical scroll (aka, $FA not equal) update g...
by infidelity
Sat Jun 19, 2021 12:15 pm
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Ok so my guess is, do I have hdma going at the start of my NMI, when the game is in vertical scroll mode?
by infidelity
Sat Jun 19, 2021 8:22 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Update 1: I've finally gotten around to properly getting my stack pushed/pulled from properly, when the NMI fires up in the middle of a 16-bit instruction. My issue was, the game deliberately hard codes the sound engine handler address within the stack, and I needed to adjust the addresses within th...
by infidelity
Wed Jun 16, 2021 6:54 am
Forum: SNESdev
Topic: Need guidance with nes to snes.
Replies: 330
Views: 84216

Re: Need guidance with nes to snes.

Update: got the vertical scroll working. The next thing I have to figure out is using HDMA to combine the two screens, since I now have a gap between the two tilemaps. Right now I'm working on one of the games irq routines, having issues where I get a millisecond glitch of the incorrect tilemap appe...