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Questions tagged [nes]

For questions about the different versions and products of the NES (Nintendo Entertainment System)

3
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1answer
214 views

Is screen wrap on the NES a fault of the OAM?

On NES games such as The Legend of Zelda and Metroid, entities that get to close to the edge of the screen, whether that be the top, bottom, left, or right side wrap around to the other side of the ...
2
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1answer
249 views

How did Konami games recognize the famous cheat code?

The famous Konami cheat code is the sequence up, up, down, down, left, right, left, right, B, A What original algorithm was used to detect that the code was entered? I can think of two possible ...
36
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5answers
4k views

Is it possible to make a ROM converter?

Based on my understanding, an emulator is necessary because the machine with the emulator on it (say Windows), doesn't execute the same machine code as the target platform (6502, for example). So what ...
16
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4answers
4k views

Are NES turbo buttons internal to the controller?

As you may know, the classic NES controller was not the only NES controller that Nintedo released with the NES. These included the NES advantage, the NES Max, and the Dogbone. All of these new ...
5
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2answers
524 views

Does the NES handle unlisted processor instructions differently from the Famicom?

As you may be aware, developers used unregistered machine codes in their games, as discussed in this thread. My question isn't why they would do this, but instead if these instructions yielded a ...
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2answers
403 views

Why does R.O.B. wear “glasses”?

So recently, I've been playing Gyromite (which sucks), with R.O.B. (which also sucks), and I noticed that he comes with sunglasses that he doesn't actually need to work properly. This was the case ...
5
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2answers
221 views

Do TG16 games and software suffer from lag frame similar to NES Super Mario Bros?

As a speedrunning fan, I've watched hours of Super Mario Bros speedruns, and have heard the term "lag frame". I don't think it's similar to typical computer lag, but instead an extremely technical ...
1
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2answers
189 views

NES PPU die photo

I found a die photo of the NES video chip: http://visual6502.org/images/RP2C02/NES_RP2C02_G_8F1_1B_20x_1600w.jpg I think the big block of fairly regular circuitry at the bottom left is the sprites? ...
30
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3answers
4k views

Did the NES do anything special to support coprocessors?

Some of the later NES/Famicom games contained not just ROM, but coprocessors for better sound and graphics than the original console hardware could provide, such as the MMC5: https://wiki.nesdev.com/w/...
34
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3answers
7k views

Were the dungeons in Legend of Zelda designed to fit together?

As can be seen in the image below, the dungeons of Legend of Zelda fit quite well together. Were they designed to be, or is this just a coincidence? Does this make them easier to store, with the ...
10
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3answers
544 views

8-bit console horizontal resolution

Some early consoles like the NES and the Sega Master had a horizontal screen resolution of 256. That sounds good for an 8-bit machine, until you consider that a sprite sometimes needs a slightly ...
3
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1answer
374 views

SNES / old graphics: merging sprite's with background [closed]

I have one question about how old computers or consoles like Super NES merged background layer(s) and spirites. Or another way - how layers were merged to not overload a PPU / CPU? OR how about ...
5
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2answers
271 views

NES/Famicom CPU address range allowable for cartridges

The postulated address range for CPU ROM (so-called "PRG-ROM") in cartridges is $8000..$FFFF, that is pre-decoded in NES/Famicom and the chipselect is fed to the cartridge. However, it is quite ...
7
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1answer
291 views

Is there a database of the box contents for different versions of NES games?

I've recently become interested in collecting old NES games. I'm trying to find an original NES Legend of Zelda game CIB. However, I'm having trouble distinguishing different versions of the game. All ...
14
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0answers
231 views

Does anyone know the specific differences between the NES-001 (NTSC) motherboard revisions?

On each Motherboard of an NES-001 (NTSC) there is a code: NES-CPU-xx These range from 04 to 11 (I think) I would like to know if these are all of the revisions of the NES and what major differences ...
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2answers
507 views

Best way to locate data on ROM? (6502 Processor)

Lately I've been interested in how old machines work, in particular an NES. While there are quite a few resources on the basic operations and even some games that have been totally broken down byte by ...
13
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1answer
878 views

What is the relationship between the Ricoh 2A03 and the MOS 6502?

The Ricoh 2A03 (and the 2A07) is the CPU in the well-known Nintendo Entertainment System. Apparently, the die is very similar indeed, as the slides in this video suggest https://www.youtube.com/watch?...
13
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2answers
576 views

NES repair - blue screen

I have an NES that was giving me a blinking red light when powering up. I had chalked this up to the 72-pin connector and set about cleaning it. After cleaning the connector and all games, the problem ...
10
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2answers
945 views

How do NES/famicon games produce additional sound channels?

The NES/famicon has always used the Ricoh 2A03, a modified MOS 6502 processor to generate the memorable music and sound effects of classic Nintendo games and continues to define the newer 8-bit / ...
8
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1answer
639 views

What is the Famicom “Pulse Line” of games? How many games are part of this line?

(This question was inspired by Did all NES "Black Box" games come in carts with five screws?) I've heard of the Famicom "Pulse Line" of games released in Japan shortly after the launch of ...
8
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3answers
541 views

Trying to understand what an “address latch” is while emulating the NES PPU

I'm attempting to emulate the NES PPU and I'm implementing its registers. In particular, reading from the PPU status register has the following effects: Reading the status register will clear D7 ...
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2answers
2k views

Is it possible to play Famicom games on the NES and utilize the extra sound channels?

I've seen there are adapters to convert Japanese Famicom games to work on the NES. You may have to remove the lockout chip, I can't remember. Anyway, many Famicom games included extra sound hardware ...
11
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1answer
964 views

Did all NES “Black Box” games come in carts with five screws?

When the NES was released, there were a list of original titles from Nintendo such as Duck Hunt, Super Mario Bros. and Metroid. These titles came in a distinctive box that was mostly black. Plus, the ...
22
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1answer
551 views

How does the NES PlayChoice arcade's security EPROM work?

I've read that the PlayChoice 10's security system includes a 64-bit serial EPROM that gets compared against the first 64 bits of code, and that it's possible to swap the ROMs between compatible ...
18
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2answers
966 views

Is it possible to procedurally determine the number of cycles a particular instruction takes on a 6502?

Most emulators store the number of cycles a particular instruction takes in an array, and then adds any conditional cycles if needed (when crossing page boundaries, for example). I'm wondering if ...
27
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1answer
2k views

How can I create a split-scroll effect in an NES game?

Games like Super Mario Bros. and Super Mario Bros. 3 were able to scroll the playfield but not the status bar: The status bars are clearly too big to be sprites, yet they don't scroll with the ...
10
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4answers
945 views

PAL NES in USA, 50Hz vs 60Hz

I was wondering if there existed a way to fix the difference in the running speeds of a PAL NES to run on TV's in the United States? Be it some converter or messing with the NES itself.
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7answers
25k views

Why would a NES game use an undocumented 1-byte or 2-byte NOP in production?

Reading the NESdev wiki page on CPU unofficial opcodes, I see a few games use an undocumented 2-byte NOP instuction in production: Puzznic, F-117A Stealth Fighter, and Infiltrator use $89 #i. Beauty ...
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6answers
3k views

Can removing a cartridge from an NES (or any other cartridge-based game system) damage the hardware or software?

On some cartridge-based video game systems (NES, Game Boy Color, etc.) it is possible to remove the cartridge while the game system is still powered on. What kind of damage can this behavior do to ...
5
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0answers
211 views

R.O.B can't move up or down

I got this R.O.B (Robotic Operating Buddy for the NES), first time I turned him on his arms wouldn't close, so I took him apart and cleaned him. I put the gears back into place. After turning him on ...
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2answers
286 views

NES only works when I press reset

My aunt gave me her old nes, it was really dirty. I opened it up, cleaned it really good, cleaned the games too. I had to get a new power pack and av cables for it. I plugged everything into my TV (...
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2answers
13k views

Why does the Minus World exist?

In Super Mario Bros. for the NES and Famicom there exists a secret world, accessible by clipping through a wall to the first warp zone and entering the left-most pipe. This pipe will take you to ...
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1answer
830 views

Can I use a UK power adapter in NTSC NES

I have an old US (NTSC) NES system which we found in the garage. Sadly the power supply is missing. As I now live in the UK, I was wondering if it is possible to use a UK NES power supply with it. ...
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2answers
3k views

How does the NES Light Gun work?

Modern motion detection video game systems (Wii/Wii U, Xbox Kinect, PS Move, etc.) need sensors to read for motion and user input. However, when you play Duck Hunt (and some other games) on the NES, ...
15
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1answer
2k views

How Did the 10NES lockout chip work?

One of the differences between the Japanese Famicom and the NES released outside of Japan is that the NES shipped with a lockout chip which prevented bootleg and imported games from working on the ...
10
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3answers
939 views

Why are the PPU registers on the NES mirrored?

The NES Picture Processing Unit has eight memory-mapped registers to the CPU in registers $2000 to $2007. The are incompletely decoded, so they are mirrored every 8 bytes from register $2008 to $...
15
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2answers
6k views

What are the differences between the Japanese Famicom and American NES?

In Japan, Nintendo's first home console was sold as the Family Computer (Famicom), while in the US it was later sold as the Nintendo Entertainment System (NES). Other than the region lock out for ...
17
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2answers
3k views

Why do NES sprites flicker when there are a lot of them?

Sometimes, NES sprites flicker when there are a lot of them, like at 1:19 in this video of Super Mario Bros. Why did they do this?
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3answers
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What was Nintendo's Software Development Environment for NES Games?

(This question was inspired by my previous question What kind of software was used to develop Nintendo 64 titles?) The NES used a modified 6502 processor and most games were written in Assembly. ...
15
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2answers
1k views

Can I run a NES emulator off the original cartridges?

Every NES emulator I've found runs off ROM dumps. Would it be possible to run an emulator using the original cartridges directly? It's probably not the most practical way of doing things, but the "...
31
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3answers
2k views

Reconditioning and cleaning old Nintendo (and other) game cartridges

I used to blow the dust out of the cartridges but I heard that can actually damage the cartridge or the system itself. I am looking for the proper way to clean old Nintendo game cartridges (such as ...