Search found 7 matches

by mrhyde
Wed Dec 25, 2013 11:33 am
Forum: NES Hardware and Flash Equipment
Topic: Two questions to MOS6502
Replies: 3
Views: 1290

Two questions to MOS6502

Hi, the NES uses a derivate of the popular MOS6502 processor. I have two questions concerning this CPU in general: 1. Sometimes an instruction needs more cycles, when a page is crossed (the 16 bit argument goes over 0xff). By example instruction 0x59 (EOR, Absolute Y addressing mode) is such an inst...
by mrhyde
Sat Dec 07, 2013 3:03 am
Forum: NESemdev
Topic: Mario Bros is flickering on my emulator
Replies: 10
Views: 7054

Re: Mario Bros is flickering on my emulator

Hi, Most of the PPU (and APU) registers are not readable - what you should be doing is setting variables during writes and then reading those variables in the necessary places. ... and update the system's state to reflect the new settings ... oh yes. You are totally right. I haven't thought about th...
by mrhyde
Fri Dec 06, 2013 6:17 am
Forum: NESemdev
Topic: Mario Bros is flickering on my emulator
Replies: 10
Views: 7054

Mario Bros is flickering on my emulator

Hi, I didn't know if I should open a new topic for this or reuse my old one here . But because of the fact that this problem is "standalone" I opend a new topic. I hope this is okay for you. For those who didn't read the other topic: I'm developing an nes emulator. Currently I'm working on the backg...
by mrhyde
Wed Dec 04, 2013 12:09 pm
Forum: NESemdev
Topic: Understanding the behavior PPU
Replies: 16
Views: 7728

Re: Understanding the behavior PPU

Hi, For details of what happens when, check the wiki. that's the page I'm looking for. Thank you. Could you give me a hint concerning my "nametable addressing" confusion? EDIT: I found this document which explicitly says: The first area of PPU memory is known as the "Pattern Tables." The pattern tab...
by mrhyde
Wed Dec 04, 2013 6:45 am
Forum: NESemdev
Topic: Understanding the behavior PPU
Replies: 16
Views: 7728

Re: Understanding the behavior PPU

Hello, [...] without a clear idea of the overall architecture. That's what I understand you to be saying, and maybe the links answer some of it. thats what I'm talking about. Anyway I decided to start with some topic in the hope that I'll end with a working PPU. So I got my hands on the pattern tabl...
by mrhyde
Wed Dec 04, 2013 3:44 am
Forum: NESemdev
Topic: Understanding the behavior PPU
Replies: 16
Views: 7728

Re: Understanding the behavior PPU

Hi, The NES PPU is nothing but niggling technical details. yes. But I need a general overview how the rendering takes place. I know about the pattern tables and name tables and that they are painted during the scanlines line per line. But I need to know how the PPU generally behaves. I hoped that so...
by mrhyde
Wed Dec 04, 2013 1:53 am
Forum: NESemdev
Topic: Understanding the behavior PPU
Replies: 16
Views: 7728

Understanding the behavior PPU

Hi guys, I'm currently writing an emulator for the NES. Yes, I know. There is this "information" and I read it. But I don't develop the emulator for "other", I'm doing this for me to better understand how those devices work and to have fun. Anyway: currently I have finished the CPU, memory managemen...