Search found 311 matches

by Petruza
Fri May 28, 2010 11:26 am
Forum: General Stuff
Topic: List of all the NES emulators in development
Replies: 46
Views: 11704

I'm developing yet another NES emulator just because I wanted to code something challenging, as opposed to my day job which is definitely not. It won't be a regular emulator which tries to emulate exactly the original NES and nothing else, it will be, I think, something new and original. No too orig...
by Petruza
Fri May 28, 2010 11:18 am
Forum: General Stuff
Topic: Coincidence?
Replies: 3
Views: 1860

Coincidence?

I just bought "On the edge" a book about Commodore business machines.
Look at the product number.
Coincidence? or the data entry guy is a retro-nerd sending a message?

Image
by Petruza
Mon May 17, 2010 12:05 pm
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

ok thanks
by Petruza
Mon May 17, 2010 9:59 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

Ok, but 21.47 Mhz means that something occurs once every 21,470,000 th of a second. We already stated that that are not PPU cycles, so what are they?
by Petruza
Mon May 17, 2010 7:20 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

Ok, so the 21.47 Mhz is some sort of video clock signal I shouldn't care about.
by Petruza
Mon May 17, 2010 6:11 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

Re: PPU render timing basic questions

Disch wrote:
Petruza wrote: Each CPU cycle equals 12 PPU cycles, CPU runs at 1.79 Mhz and PPU at 21.47 Mhz.
No.

1 NTSC CPU cycle = 3 PPU cycles
1 PAL CPU cycle = 3.2 PPU cycles
I'm confused, so why does the NTSC PPU run at 21.47 Mhz which is 12 times the 1.79 Mhz of the CPU ?
by Petruza
Sun May 16, 2010 9:33 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

Re: PPU render timing basic questions

HBlank as used in descriptions of NES hardware is any part of the scanline that is not dots 0-255. But in other descriptions it's time similar to VBlank where writing to the PPU is safe. Of course the NES has no such time between scanlines because it's always busy fetching. So no writes to VRAM can...
by Petruza
Sun May 16, 2010 9:04 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

Re: PPU render timing basic questions

The source of timing in my emulator are the instructions that are being executed, so for each CPU cycle executed in its instructions, I advance the PPU renderer ** cycles. That's a slow way to do it, but yeah that's the basic idea. So what would be a better/faster way? I like your idea of master cy...
by Petruza
Sun May 16, 2010 8:35 am
Forum: Newbie Help Center
Topic: PPU render timing basic questions
Replies: 18
Views: 7913

PPU render timing basic questions

Source: Brad Taylor's NTSC 2C02 tech ref (This post implies NTSC) I finished the CPU emulation, and heading now towards the PPU. I'm finding the PPU render timing really complex, so I want to know if I understand it at least roughly so I can start to figure out how to implement it. So What I underst...
by Petruza
Sun May 16, 2010 8:34 am
Forum: Newbie Help Center
Topic: Getting Started(Updated:Jun. '10)
Replies: 21
Views: 77166

It would be great to have such a sticky for emulator development.
by Petruza
Sat May 15, 2010 10:15 pm
Forum: NESdev
Topic: C/C++ NES programming
Replies: 26
Views: 15962

65024U wrote:Sorry I dragged this so far off topic, I just really want to know how big windows really is and stuff that very moment XD

So....Anyone every think of making a NES cart that could be used for developing games?....FROM THE CONSOLE? *GASP*
Please don't follow the path of Joe_Cracker
by Petruza
Sat May 15, 2010 9:40 am
Forum: NESdev
Topic: C/C++ NES programming
Replies: 26
Views: 15962

Yeah well I think it definently is possible to make a OS Well sure, there were some OSes code in assembler, I don't say it's impossible, I say it's highly impractical as developing any big project in assembler. A 3.2GHZ PC with a OS in assembly? Fastttttt ^_^ :P Linux is coded in C and it's fast, I...
by Petruza
Sat May 15, 2010 8:42 am
Forum: NESdev
Topic: C/C++ NES programming
Replies: 26
Views: 15962

I'm not even gona lie, I think C is evil....especially when people debate what's better, C or assembly, which is too obvious ⌐.⌐ :P :roll: For the domain of this forum which is NES and 6502 Programming, I would agree Assembler is by far the best choice. Hahahah, I ment as in the development of a pr...
by Petruza
Thu May 13, 2010 8:47 pm
Forum: NESdev
Topic: NesASM 3.01 addressing and syntax errors
Replies: 7
Views: 3785

Ooops!
Neither the docs nor the example codes had any indirection example, so I guessed ()
Gonna try, thanks!
by Petruza
Thu May 13, 2010 8:18 pm
Forum: NESdev
Topic: NesASM 3.01 addressing and syntax errors
Replies: 7
Views: 3785

NesASM 3.01 addressing and syntax errors

I've got NesASM 3.01 from here: http://www.nespowerpak.com/nesasm/ Not the .exe since I use MacOS, but built the sources. I'm coding a simple CPU test, and get this errors: 67 00:C02B STX $0,Y Incorrect addressing mode! 105 00:C056 STA ($0,X) Syntax error in expression! Isn't STX ##, Y a valid instr...