nesdev.com

Say I want to test theories about graphics compression, such as adapting UFTC/XFTC or some sort of RLE or XOR Huffman to TG16, SMS, Genesis, Super NES, or GBA. I'd like to run multiple codecs on a corpus, compare their rate and decoding time, and post the corpus, codecs, and results on GitHub so tha...

If the divisor is fixed at 10, "the usual division routine" unrolls to this 55- to 59-cycle fragment: ldx #0 stx quotient cmp #160 bcc @L1 sbc #160 @L1: rol quotient cmp #80 bcc @L2 sbc #80 @L2: rol quotient cmp #40 bcc @L3 sbc #40 @L3: rol quotient cmp #20 bcc @L4 sbc #20 @L4: rol quotient cmp #10 ...

If [games made for ZSNES] don't work on real hardware they certainly shouldn't be allowed to work on an emulator either. Then the obvious solution is to build real hardware that runs them :twisted: Expand ARAM to 128K Option to put echo buffer in top half ($10000-$1FFFF). No incomplete results for ...

In before someone builds hardware that modifies the platform to use 128K ARAM, with the echo buffer in the top half.

Split to Hardware-implementable emulator inaccuracies.

Starting at $C6BD, nestest.nes indeed tests the behavior of those unofficial 6502 instructions that are stable. However, only about a dozen pre-1997 licensed and unlicensed games rely on them. If you're that far, you can stop and begin the PPU if you wish. Further reading: CPU unofficial opcodes ; P...

nocash wrote: ↑

Fri Feb 14, 2020 10:07 am

No, that's nonsense the SNES does draw (consume) power, it does not supply (generate) power.

Both. It draws power through a 7805 regulator, and it uses some of that power to supply power to the Game Pak and controllers connected to it. ("Supply" doesn't necessarily mean "generate".)

Write one value to $A130F1, and $000000-$3FFFFF is ROM. Write another value, and $000000-$1FFFFF is ROM and $200000-$3FFFFF is RAM.

Further reading: "Saving progress with SRAM: Games larger than 2MB" and "MOVEP instruction: Using movep to read/write SRAM" on Plutiedev

The .sym file format is used by the debugging features of NO$GMB and bgb emulators. WLALINK and RGBLINK generate this format, and the mgbdis disassembler accepts it as input. Each nonblank line contains either a semicolon and comment or a bank (1-3 hex digits), colon, address (4 hex digits), whitesp...

Games larger than 2 MiB that have battery-backed SRAM have a mapper to switch $200000-$3FFFFF between the upper 1 or 2 MiB of ROM and the SRAM.

The 68K architecture is big-endian: $1234 is stored as 12 34. This means $200000 is high and $200001 is low.

Or when making a Super Game Boy native mode game (like Space Invaders). Or when making a multicart menu (similar to removing the cartridge).

Something I plan to do this year, and something I've done.

byuu wrote: ↑

Wed Feb 12, 2020 12:19 pm

I'm updating the name in places that allow me to. phpBB3 isn't one of them.

If you do want a username change, feel free to request one.

In before the obligatory Far Automata jokes...

Check your soldering on the pin that carries VRAM A2/D2 and PPU-to-CPU D2. (On a PPU with the same pinout as the NES PPU, these are pins 36 and 4 respectively.)

User dinkc64 is now dink

tokumaru wrote: ↑

Tue Feb 04, 2020 3:41 pm

Well, external hardware simply can't change a flag inside the CPU.

For the sake of completeness, there is one exception that applies to some other applications of the 6502, but not the NES. Thus I won't go into detail about it.