nesdev.org

OK, I looked into it and I can get it to run, there are 2 lines to change and 3 to add. That wont make it good code to reference, but it will do what I think the author intended. Find the reset subroutine and fix what is being written to $2000 and $2001 change $2000 so it writes $88 instead of $80 c...

OK, I downloaded this from Mark Knibbs site and the .nes rom he includes also doesnt work (which I assume he also compiled from that source). I ran it in Nintendulator and the screen is grey. So I would say there is a bug in the code. It looks like the nametables are setup, but the screen doesnt dis...

I've been using CA65 for almost a year now. MY first game ws NROM which was failrly easy to setup in terms of the code and linker files. Now I am checking out UNROM. I've goten things setup and working, but it just feels like a kludge. I was thinking I would show what I have, and let people share th...

Thanks. I havent written an emulator, but I did write a 6502 core as part of a "not very good disassembler", so this'll be useful for me.


Edit - I still have a lot of work to do before I can truly use it.

Al

Is nestest hosted anywhere else? The link on the wiki doesnt work for me. Sorry for hijacking the thread.

Al

Ah OK. I was mis-understanding 2 very important things. 1) I was miunderstanding the branches. I was mistakenly thinking they were branching forwards, lol. Thats just me being a fool. 2) I was misunderstanding thinking that the hit flag was cleared at the time the NMI was fired. This was a huge mis-...

I think I'm still not grasping one important concept. That is, when does the hit flag (bit 6) of $2002 go OFF. The reason I am not grasping this, despite very good responses listed above, is that this piece of code invoked within the NMI works. : BIT $2002 BVS :- : BIT $2002 BVC :- The Overflow flag...

Thanks guys. Edit- Even though I have it working, I'd still like to understand sprite #0 better Here's what I have read, please correct me if I am wrong: Most of this is from NES Architecture document 2.6 dated Jan 2005. 1) Sprite #0 must intersect the background on a pixel where neither the backgro...

It appears that if I just position my sprite #0 so its X position is 248 (the far right of the screen) all my timing issues go away For me, I was only planning on using sprite 0 for the status bar, not as a specific sprite to be seen, so for my purposes, this seems to work in Nintendulator for NTSC ...

Thanks guys, I'll give it a try. Although my second nametable is transparent in that upper region. I didnt realize that there was "timing" involved. I knew I had to get a few things done in a short period of time, I just thought I could detect an hblank for sprite #0 I'll let you know how ...

I'm thinking that your response is for a status bar at the bottom of the screen. I should have mentioned mine is at the top of the screen. Here's a pic of the glitch. The black at the bottom right of the status area varies in width as I scroll. Anywhere from 0 to 6 pixels in width. http://i51.photob...

I have a question about using Sprite #0 for split screen side scrolling (horizontal scrolling) I have what looks like workng code, but I see a small graphical artifact along the right edge of the screen on the same scanline as my sprite #0 is located. (I am using Nintendulator). My sprite #0 is a ho...

When I used color 0x0D for Sudoku it was really shaky (unplayable) on my LCD TV. On my older CRT TV it was fine.

If you dump Immortal, can you try it on a power pak and see if the problem is ROM rather than hardware?

Al

How long do you think the CIC (on the jukebox) would need to be disconnected for the CIC in the NES to register that there was a mismatch and re-trigger a reset?

I'm getting more and more intrigued with this idea.

Al

4) A Power supply that can power n game cartridges because games aren't guaranteed to have a low power mode. Maybe 200mA per game. If you did 16 games, that would require a ~3.2A power supply, very hefty unless it's a switching supply. The best option would be to reuse a PC power supply which would...