Search found 134 matches

by Nessie
Thu Jun 21, 2012 8:22 am
Forum: NESemdev
Topic: DMC DMA causing double-$2002 reads?
Replies: 10
Views: 5796

cpow wrote:If anyone else finds this interesting...
Just want to say I find this interesting but can't post any meaningful response because I'm having trouble following what's actually going on :)
Have to do some testing myself with blargg's framework before I'll be able to wrap my head around this.
by Nessie
Thu Jun 21, 2012 7:10 am
Forum: NESdev
Topic: Programming for the NES in C or C++
Replies: 56
Views: 12120

Depending on how capable the assembler is, advanced macros can sometimes be a great substitute for real C code without hurting performance as much. However, since C is such a ubiquitous language, it automatically comes with many other benefits e.g. reusable code, large toolset with syntax highlighti...
by Nessie
Mon Jun 18, 2012 12:14 pm
Forum: NES Hardware and Flash Equipment
Topic: Has anyone ever actually seen these? (mapper 19)
Replies: 4
Views: 1794

Perhaps you could browse bootgod's database for pictures? There are some blob free namco chips there.
by Nessie
Mon Jun 11, 2012 12:01 pm
Forum: NESemdev
Topic: Multithreaded emu designs
Replies: 54
Views: 41178

Cooperative threading seems to simplify the source code by an order of magnitude compared to a typical state machine. But how do you handle save states? The thread context can't really be saved. Did you decide on some sort of "safe" point (e.g. start of vblank) where all the threads can be told to s...
by Nessie
Sun Jun 10, 2012 4:04 pm
Forum: NESemdev
Topic: Bit toggling detection (blargg mmc3 tests)
Replies: 6
Views: 2023

Your function could look something like this: void update_vram_address(unsigned int new_value) { unsigned int old_value = vram_address; vram_address = new_value; if ((old_value ^ new_value) & 0x1000) { // A12 changed! bool new_a12_state = new & bitmask; a12_changed_to(new_a12_state); } } but as Dwed...
by Nessie
Sun Jun 10, 2012 2:26 pm
Forum: NESemdev
Topic: Bit toggling detection (blargg mmc3 tests)
Replies: 6
Views: 2023

Code: Select all

bit_changed = (old ^ new) & bitmask;
new_bit_value = new & bitmask;
by Nessie
Sun Jun 10, 2012 11:31 am
Forum: NES Hardware and Flash Equipment
Topic: CopyNES client in Python
Replies: 0
Views: 1431

CopyNES client in Python

I started working on a CopyNES client in Python today and it's coming along pretty good. Perhaps it could someday become a cross platform alternative to the official software. Operations supported so far: - Check BIOS version - Dump memory contents - Dump ROM - Upload ROM to PowerPak Lite I've manag...
by Nessie
Sat Jun 09, 2012 5:58 am
Forum: NES Hardware and Flash Equipment
Topic: USB CopyNES and Windows 7
Replies: 21
Views: 8785

I'll see if I can put together a CLI in python. This is for the powerpak lite, right?
by Nessie
Fri Jun 08, 2012 6:24 pm
Forum: NES Hardware and Flash Equipment
Topic: USB CopyNES and Windows 7
Replies: 21
Views: 8785

The CopyNES protocol is really simple to implement so if you're only looking for a way to play ram carts you could make your own client. Using python and pyserial it shouldn't take more than 100-200 lines to create a decent command line interface for ram carts. Other features such as bankwatch would...
by Nessie
Sun Jun 03, 2012 5:39 am
Forum: NESdev
Topic: NMI/IRQ and cycle delays
Replies: 1
Views: 1625

It's 7 cycles. This page has some relevant visual 6502 tests for special cases, interesting stuff.
by Nessie
Mon May 21, 2012 12:50 pm
Forum: NESemdev
Topic: byuu's XML format
Replies: 52
Views: 11099

I've been watching discussions on formats for a long time, it's a predictable pattern. Guy comes up with format, most people throw a fit because iNES 1.0 is just fine, and they don't want to support anything more than their iNES+DB that's already working for them. Guy tries to get more people on bo...
by Nessie
Fri May 18, 2012 6:33 am
Forum: NESemdev
Topic: byuu's XML format
Replies: 52
Views: 11099

byuu's XML format

v089 and above will only load images in the FC spec: Super Mario Bros.fc/ * program.rom (Super Mario Bros.nes sans first 16-bytes) * manifest.xml <cartridge> <board type="NES-NROM-256"/> <mirror mode="vertical"/> </cartridge> * save.ram (not for SMB, but for other games.) ... avoid my issue of tryi...
by Nessie
Fri Mar 16, 2012 9:48 am
Forum: NESemdev
Topic: NES Emulation History
Replies: 27
Views: 20459

Krasivsky's emulator seems to have been called LandyNES, it is mentioned further down on that same nesworld page.
by Nessie
Sun Aug 14, 2011 12:40 pm
Forum: General Stuff
Topic: Is Java so inefficient
Replies: 10
Views: 3701

Java is very probably more efficient than all interpreted languages (such as PHP) as it's compiled to a bytecode, but then the bytecode has to be interpreted by JRE instead of being directly executed This was true in 1995 when Java was first released, but for the past decade Java has been running o...
by Nessie
Wed Jun 08, 2011 5:53 pm
Forum: NESemdev
Topic: Error #6 in Ppu Access in Blargg's PPU Test
Replies: 4
Views: 2209

Reading $3F00-$3FFF should work just like $3000-$3EFF, i.e. a nametable byte should be put in the VRAM buffer as usual. However, the value that is finally returned to the CPU will not be the what was previously in the VRAM buffer. Instead, it will be a value from the palette. Something like this: re...