Questions tagged [game-boy]
Nintendo Game Boy and Game Boy Color: use, maintenance, design, programming and emulation.
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Was the Game Boy CPU a completely new layout?
As explained on the Wikipedia Game Boy article and Is the Game Boy Sharp LR35902 object-compatible with the 8080/Z-80?, the Game Boy used a custom CPU that was fairly close to being a superset of the ...
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Why would poking an inserted Game Boy cartridge while powered on cause a game/device to hang? [duplicate]
I say "a device" because I'm not convinced that this happens on an actual Game Boy. (I haven't been able to provoke it on mine yet.)
I've seen several videos of people showing how their ...
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Why did the Nintendo GameBoy Color make the name of any game to have a specific checksum?
Inside of the GBCs Cartridge header there is the metadata for the game and the Nintendo logo.
The program that runs on boot (the BIOS or Boot ROM) checks the checksum of the Nintendo logo, and always ...
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How does the GameBoy Colors' display work in color?
I know the GameBoy originally worked in a 2bpp display functionality, with 4 shades of grey, but how does the GameBoy Color tiles work with colors? No website seems to have a obvious and ...
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Are there other Game Boy replicas than the Analogue Pocket that can run Game Boy cartridges?
The Analogue Pocket can run Game Boy Cartridges. Are there any other, currently-available, clones that can do this?
(The on-topic nature of this question was discussed on Is asking for the existence ...
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Is there an equivalent of "#pragma once" in RGBASM (Gameboy DMG assembly language)?
So I am really just starting out in my assembly coding adventure. I have a little bit of knowledge of C/C++ but nothing too advanced yet.
But I also used to do a tiny bit of Z80 assembly, and I wanted ...
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Is there an obstruction to emulating Gameboy link cable over Wi-Fi?
Emulation these days is well supported for loads of systems, and I understand that original Game Boy and Game Boy Colour are comparatively simple to emulate.
Retro gaming is also pretty popular at the ...
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Does the Super Game Boy have any battery powered non-volatile memory?
I'm not sure if my copy of the Super Game Boy is broken, or has had its internal battery run out of power, but it doesn't seem to retain any information.
In particular, I'm annoyed by how it doesn't ...
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Why do Game Boy Colors not want nickel-cadmium batteries?
This is a page from the manual for the Game Boy Color:
There is no explanation as to why this is, or how this can be, but it claims that one must not use rechargeable nickel-cadmium batteries.
Why is ...
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Does Game Boy Color have *perfect* simulation of original Game Boy games?
In recent years, I've learned that the Super Game Boy peripheral for the SNES did not run Game Boy games at the exact right speed; they were slightly faster.
Now I'm worrying that the same (or ...
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Game assembled using RGBDS can't access cartridge RAM
Any writes I do to cartridge RAM on my test game assembled with RGBDS are silently ignored. I wanted to move the stack pointer to cartridge RAM to have more room in high ram to use as a scratchpad, ...
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Is "scroll tearing" a symptom of scanline interrupts taking too long?
I was trying to implement multiple LYC IRQs to implement faux parallax effects (like in Game Gear Shinobi), and my method was to begin LYC interrupts at a particular scanline, say about halfway down ...
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Can the window only be moved once per frame on the Game Boy?
I wanted to cover the top part of the screen to use as a status bar for a game. My idea was to use the Game Boy's window feature to do so. But I ran into a problem: The window's size is fixed to be ...
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Getting a loading seam to work with 2x2 metatiles
I'm working on a prototype for a scrolling loading seam similar to Pokemon where the screen scrolls incrementally by 8 pixels with each direction button press, and new tile graphics are drawn off the ...
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Game Boy interrupt handler crashes unless I jump to it indirectly
I have an interrupt handler I created, which is meant to reduce the overhead of interrupts as much as possible. Setting up the interrupt handler is done while interrupts are disabled, of course. It ...
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Can I use cartridge RAM for the stack pointer?
My understanding is that the extra cartridge RAM banks at &A000-&BFFF are battery-backed SRAM that is preserved after powering off the game. If I'm making a simple game that doesn't have a ...
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How did Legend of Zelda: Oracle of Seasons/Ages know it was running on a Game Boy Advance?
I remember finding out there was a secret area in both games that you could only get to if you were playing on a Game Boy Advance. Even the 3DS releases don't allow access to them. My question is, how ...
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How can I detect signed integer overflow on the Game Boy?
Unlike a normal Z80, the Game Boy has no CALL pe/po, JP pe/po or RET pe/po instructions. I've been trying to figure out how to detect integer overflow on the Game Boy. (It doesn't have those ...
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Why does the GameBoy Pocket produce a blue line on power off?
Ever since I first had my GameBoy Pocket, I've noticed that the line drawn across the screen at power off (which I'm guessing is because the CPU has stopped sending clock signals to the display driver,...
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Why do Game Boy games have explicit save functions, instead of using battery-backed non-volatile cartridge SRAM to store the game state?
Game Boy games used a battery-backed SRAM module for their save states. Since the SRAM module retains its whole content, why do Game Boy games always need a manual save operation?
Wouldn't it be much ...
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Did the Super Game Boy (1) run 2.5% or 4% faster than a Game Boy?
For years, I've heard "4%", repeated over and over. But then I read this today:
The original release of the Super Game Boy runs about 2.5% faster than an original Game Boy.
And the source ...
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What could be the reason an `LD B, B` instruction was used in this busy loop?
The Game Boy game "Tetris" leaves a transmission interval of about a millisecond between bytes sent over the serial link, as suggested by the official Game Boy Programming Manual, to give ...
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Startup behavior of Gameboy - what to replicate in an emulator? [closed]
I'm new here. Let me know if this is the wrong place to ask this kind of question.
I'm planning to build a Gameboy emulator. Before I start, I want to have a clear understanding of the startup ...
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Why do sprites lag behind a scrolling map in first-generation Pokémon games?
This is something I often notice whenever I see a first-generation Pokémon game being played on a Game Boy emulator. It might be present on real hardware as well, but I don’t have that to test.
When ...
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Did the RTC in certain cartridges get power over the GBA bus?
Some GBA games, like Pokemon Ruby, contained an internal RTC with a small button battery to power it. When the cartridges were inserted and the GBA was powered on, did the RTC continue to run on the ...
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How can a Game Boy game "glitch-inherit" the music from a different game like this?
Just now, I saw a stream of a person playing Game Boy games. The technical setup is like this:
Real American SNES.
Real Super Game Boy 2. (Only released in Japan; fixes the speed bug in the Super ...
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When was the Game Boy Pocket released in Europe?
You'd think this would be the simplest thing in the world to find out, but Wikipedia and all other sources just mention the USA and Japan release dates -- not the European one. I have no idea why ...
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In Tetris on Game Boy, does the speed increase depend on time or on the number of points?
I always start at level 9, game mode A.
At some point, whether it's based on time or the number of points, the blocks start falling so fast that the "down button" feature loses all meaning; ...
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Why doesn't Nintendo fire up the old factories and re-produce *exact* copies of many of their most popular games, controllers and consoles? [closed]
Let's suppose that Nintendo announce tomorrow that they are going to create exact re-releases of the American and European NES, SNES and Nintendo 64 consoles, exactly the same as when they were ...
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How does the GameBoy's Memory Controller MBC1 Work in Mode 1?
In short, are banks 20h/40h/60h accessible in mode 1?
The Pan Docs state that when in mode 1, those banks become accessible.
"...on large carts (using the secondary banking register to specify ...
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On the LR35902, what does the assembly 'LD (HL-),A' do?
I'm working on implementing the instructions of the z80 chip inside a gameboy for an emulator. I'm starting with the instructions in the boot rom that sets everything up.
I've implemented the first 3 ...
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How does the RST operation of GameBoy (SHARP LR35902) work?
The GameBoy CPU Manual talks about restart operations on page 116. Each of these operations push the current address onto the stack, and then jumps to a specific address (0x00, 0x08, 0x10, etc, ...
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How can I fix this clacking sound made by the Game Boy speaker?
I have a Game Boy, and whenever it tries to play sound, the sound is very quiet but there's a loud clacking sound.
Here is a sample. In this case, it is Tetris Attack playing:
https://soundcloud.com/...
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How do you switch ROM banks on Gameboy MBC2 Cart with INLRetro dumper
I have an INLRetro cart dumper. The software for the device is incomplete and in beta form. I've been able to dump Tetris and it works (because it's ROM fits into bank 0). When I attempt to dump ...
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How is the LCDC (LCD Control) register manipulated on the Gameboy?
I don't see it listed anywhere in the 0000-ffff address space. Is it controled by the CPU? Or something else entirely?
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What technological limitations required the "box" system in gen 1 Pokémon games?
In Pokémon Red/Blue (USA, I'm assuming in other gen 1 releases as well), you can carry 6 pocket monsters with you at once. Extra ones are stored in "boxes" on the computer. If you have 6 ...
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How does the Gameboy Link Cable work?
I've been looking into implementing Gameboy Link Cable compatibility into Bizhawk (which does not support it yet) using Lua. The problem is that I can't find any mention of how it works online.
I ...
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Why is the Interrupt Enable Hardware Register in the HRAM area on the Gameboy?
It's something I've always been wondering:
Almost all of the hardware registers on the Gameboy are placed between $ff00 and $ff7f (with plenty of gaps and empty space), the HRAM is located between $...
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Is the Game Boy Sharp LR35902 object-compatible with the 8080/Z-80?
(Note: by "object-compatible" I mean that the opcodes and their following operands are the same—the assembler produces the same output for equivalant assembler mnemonics. This of course ...
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How does Game Boy / Sharp LR35902 HRAM work?
The Nintendo Game Boy has RAM called "HRAM" (meaning "high ram")
decoded at locations $ff80 through $fffe. (All other decoded
locations in the $ffxx page appear to be I/O device and system
control ...
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On a Gameboy, what happens when attempting to read/write external RAM while RAM is disabled?
According to the GBdevwiki:
0000-1FFF - RAM Enable (Write Only)
Before external RAM can be read or written, it must be enabled by
writing to this address space. It is recommended to disable ...
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How does the Gameboy address external hardware?
Where in the memory map ($0000-$ffff) does the Gameboy address the memory of these accessories? (for example, the battery or the Gameboy Printer). Is this something I should implement in an emulator?
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What does a Nintendo Game Boy do when turned on without a game cartridge inserted?
When a Nintendo Game Boy is turned on, it displays a logo read from the cartridge (looking like this) before starting the game. What does it display if there's no cartridge inserted from which to read ...
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Why is the unchangable Nintendo Game Boy logo in the cartridge?
According to Gameboy [sic] Development Wiki page The Cartridge Header, locations 0x104 through 0x133 in the cartridge contain a bitmap of the Nintendo logo that's displayed when the Game Boy is turned ...
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How does the Gameboy's memory bank switching work?
I'm writing a Game Boy emulator, but I don't completely understand how its memory mapping works. Here is what I (think) I know (and don't know).
The CPU can address up to 0x10000 memory locations ...
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How did the Game Boy Advance stretch Game Boy games to widescreen?
The original gameboy, GBP and GBC all had screen resolutions of 160x144[1] while the Game Boy Advanced had a resolution of 240x160[2]
So how does the actual stretching occur? It seems pretty uniform, ...
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How did Satoru Iwata compress Pokemon GS to fit two regions on a single cartridge?
Satoru Iwata's story of saving the development of Pokemon Gold & Silver by compressing its assets to fit on the GameBoy Color cartridge is something of a legend. Iwata optimised the game so much ...
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What don't I understand about this LR35902 code?
The question you are now reading is about a comment on this question, about overflow bugs in some Pokemon game. A comment on that question says:
It was Game Freak's first project. They just were ...
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Is my Japanese Pokemon Red cart fake or damaged?
I recently got this copy of Pokemon Red (JP). After an indeterminate amount of time (anywhere from 30 seconds to 30 minutes), it will cause my GB Player to crash. I have functional copies of Yellow ...
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Role of the Z80 co-processor in GBA games
The Nintendo Game Boy Advance had a Z80-like processor which was typically used for backwards compatibility with GB and GBC games. According to its Wikipedia page, an uncited comment claims that this ...
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