nesdev.org

Hi,

I've made a SNROM devcart and the only the I need to test it is the EPROM chip. But I can't find any 27C256 chips with 32 pins.

Does anyone know where I can order some. I've looked everywhere.

Rewiring EPROMs doesn't affect SRAM at all.

Just wanted to make sure. Thanks Bregalad.

Sorry to bring up this topic again but I was wondering. I found "Using EPROMs in place of NES Mask ROMS", and was wondering if the instructions for SLROM will work for SKROM?

Thank you so much everyone. I decided to skip sound update if in the middle of a mmc reg3 write. If a skip, like tepples suggested, the next frame/nmi call will compensate for it. I did extensive testing with two different tunes playing (not at the same time) in the background and I could not hear a...

Sorry to bug all of you again, but I have alittle problem. In my project (uses MMC1, last 16k at $C000 is fixed), when I switch banks to obtain data or perform a subroutine, I store the new bank number in RAM, push the old one, and write to MMC 1 reg3, do whats needed, restore old bank number from s...

But if that's the case, Nintendo used the 28-pin 128kb PRG chip, wich has no programmable counterpart. The largest programmable chip that's still 28-pin is only 64kb in size. If you are willing to use a 28-pin 64kb chip in place of a 28-pin 128kb MASK ROM, I had succes with some W27E512 chips, and ...

I understand. Thank you for your help everyone. I plan to just make use of .ALIGN.

Hello, everyone. I would like to make a devcart out of an extra copy of Dragon Warrior (1 US) I have. I have a pretty descent demo of a homebrewed game I'm making, and I wanted to do tests on the real NES. I intended it to run on a SAROM cart. I planned to use 128k of PRG ROM and 64k PRG ROM. The qu...

mbrenaman wrote: How would I make sure they're at even address [...] I'm using ca65 by the way. .ALIGN Excellent. This is something I was looking for. I think you are misunderstanding the basic opcodes. JMP absolute has no pathological behavior. JMP indirect does when the low byte of the intermedia...

The values to jump are yes. But its a 2 byte storage area, not a list of address/pointer type vars. I just use the .proc command to close the scope around the routines. All of the them that need to be jumped to are stored in the same basic area, one after the other, depending on use.

Ok, thats fine. I'm just readjusting them with NOPs. How would I make sure they're at even address other going to the listing file after compilation and finding the bad ones.

I'm using ca65 by the way.

I use jump absolute in a few places in my project, and was wondering if there was a good workaround for the jmp ($xxFF) bug. Really, I just need the ability to get to a routine variably (I'm not a very good explainer). But when the needed routines address is stored in temp memory.

Thank you everyone for your help. I've come up with alittle rectangle testing routine that, as far as I can tell, works great (from testing I did). .proc map_test_rec ; In : ; rx = Rectangle's Top Left x pos ; ry = Rectangle's Top Left y pos ; width = Width of rectangle ; height = Height of rectangl...

I'll explain more. In my little RPG project, map coordinates are always from (0-map_width-1,0-map_height-1), even on the world map which wraps around. To test if other entities are on screen or to test which random encounter region the player is in, I need to test if a point lies in a given rectangl...

I have a question about wrap-around maps (maps with no edge clipping). How do you test if a point on that type of map is in a specific rectangular area?