nesdev.org

Yeah, the major confusion comes from the fact that "const" is used for a read-only variable while #define is used (among other things) for real constants. This is an amazingly insightful observation. There isn't anything more at fault for all the buffer overflow exploits than the mixup in...

The B-Bus is an implementation of the "I/O Ports versus Memory Storage" concept that a lot of 8-bit CPUs had at the time. Since the CPU in the SNES has a "Motorola" heritage, then of course this port area is visible in the memory address space. As opposed to the "Intel"...

I want to help people out in learning electronics. I don't want people to feel ashamed for asking simple electronics questions, but kind of wish people would back out a bit and see the overall view instead of demanding an answer to a specific goal, getting that answer, then just disappearing (made t...

It looks like Western Design Center is re-releasing their 65816 C compiler, and they've reduced the price to $40: That sounds a bit expensive; $40 may or may not provide value, depending on the merits of the product itself (how useful it is). it also depends on how one values his or her time... wha...

haochao:

describe the power supply you are using to power your snes.

since you have the board out of the cartridge shell, try just cleaning off those contacts with a pink pencil eraser. There is a major color difference between the top and bottom of each of the contact pads. I still stand behind just cleaning it with isopropyl alcohol, but finding a pencil eraser tak...

Use the official super nintendo cleaning kit on all the consoles that this game is going into, and clean the edge contacts of all game cartridges that are going to be plugged into these consoles. If you get quality cotton swabs, you can use them with isopropyl alcohol to clean the metal contacts on ...

or, 3rd option:

load multiple games of the same fractional size on the bigger flash chip: if you have a 4 MB chip, load four 1 MB games in it.
Then use a selector switch or dip switches with pulldown resistors on the uppermost address lines to choose what game to play.

You don't do anything with a header.
headers were for floppy disk copiers.

Let's say you have a 1 MB image you want to put onto a 1 MB NOR flash chip... The ROM image had better be exactly 1045876 bytes. That's why they're called ROM images, byte for every byte they're a 1:1 copy (an image).

what assembler will assemble the code posted? where are all the symbols defined? A section showing "During vblank period, DMA the OAM buffer, into OAM." is not present. how is this done? what startup code is needed in order to get the SNES into a condition to run the code you posted? In ot...

That mapping is more in line with how the memory map for mode 20 (LoRom) is laid out. I believe it will work for your situation (other games might not like that SRAM located over so many banks) Please remember to also have pin #23 /CPURD going to an /OE on your flash chip, in case there is an attemp...

none of those correctly deal with the A15 low = backup SRAM, A15 high = cart ROM this is especially important for that huge 4 MB flash size. i'm sure the original wiring for the 74139 could have gotten lazy and omitted A15, because the 1 MB ROM could be made to not overlap into the SRAM space, and t...

At 4 MB, you don't really need an address decoder. I don't have enough information about both games, Does college slam basketball have a save battery? Does college slam basketball use the LoROM, or HiROM mapping? Assuming college slam basketball is LoROM and has save memory... For the flash chip: Yo...

yeah, fix that instinct bug... Okay, no really. seriousness... it wasn't that bad of an assumption. What is the size of the (presumably Flash ROM?) chip that is holding the 4 MB (32 megabits) of program? Is it just one gigantic 4 MB chip, or are there multiple chips? To leave out that key bit of inf...

A CPLD would be nice to do the hi/lo switching... but I'm trying to stay with non-programmable, non-specialized devices... Just using some I.C. switches.... maybe that's craziness.... but I'm real close in my design. Just need an accurate Hi-ROM 139 wiring specs to go forward. Mark I.C. switches? D...