GameBoy Advance Introduction
This article will be an introduction for you, to the wonderful world of Nintendo GameBoy Advance. I'm going to post more tutorials here.
But it already has an OS?
A gameboy doesn't have an OS. It does however have a BIOS that shows the boot screen and contains some support routines that you can use. After a ROM is bootstrapped, most games ignore its presence entirely.
When you're developing a game or a OS for this Nintendo platform, you communicate directly with the hardware, different from what Sony PlayStation Portable does(that have an OS layer to help you to do all), if you want to put something on the screen, you need to do all on something like a "Protected Mode"(this was just to illustrate for the beginners), that is communicating with the hardware without any kind of OS layer, and the same for the audio, input and all...
Then, before you go inside this ARM world, you should know that the hardware will be all that you have, the address table of GameBoy Advance will your best friend on your journey.
Length: approximately 14.45cm Width: approximately 2.45cm Height: approximately 8.2cm Mass: approximately 140g Screen: thin-film transistor (TFT) color LCD Power: 2,4 AA batteries Battery life: approximately 15 hours on average while playing Game Boy Advance games (also dependent on the Game Pak being played and the volume setting) CPU: 16.8 MHz 32-bit ARM7TDMI with embedded memory Memory: 32 kilobyte + 96 kilobyte VRAM (internal to the CPU), 256 kilobyte WRAM (outside the CPU). Resolution: 240 × 160 pixels Color support: 15-bit RGB (16-bit color space using 5 bits depth per channel), capable of displaying 512 simultaneous colors in "character mode" and 32,768 (215) simultaneous colors in "bitmap mode"
Game Boy Advance SP
In early 2003, Nintendo introduced a new form-factor for the handheld, known as the Game Boy Advance SP (model AGS-001). The redesigned unit resembles a pocket-size laptop computer, including a folding case approximately one-half the size of the original unit. It also sports a rechargeable lithium ion battery, a significantly brighter LCD screen, and an internal front-light that can be toggled on and off. The redesign was intended to address some common complaints about the original Game Boy Advance, which had been criticized for being somewhat uncomfortable to use, especially due to an overly dark screen.
Around the same time as the release of the Game Boy Micro, Nintendo released a new backlit version of the SP (model AGS-101) in North America (commonly referred to as the "GBA SP+", SPII, or SP2). The switch that controls the light now toggles between "normal" (which itself is already brighter than the original Game Boy Advance SP's screen), and "bright", an intense brightness level similar to an LCD television set.
Game Boy Micro
In September 2005, Nintendo released a second redesign of the Game Boy Advance. This model, dubbed the Game Boy Micro, is similar in style to the original Game Boy Advance's horizontal orientation, but is much smaller and sleeker. The Game Boy Micro also allows the user to switch between several colored faceplates to allow customization, a feature which Nintendo advertised heavily around the Game Boy Micro's launch. Nintendo also hoped that this "fashion" feature would help target audiences outside of typical video game players, much like its Wii. Unlike the previous Game Boy Advance models, Game Boy Micro is unable to support Game Boy and Game Boy Color titles. The Game Boy Micro did not make much of an impact in the video game market as it was overshadowed by Nintendo's other portable, the Nintendo DS.