[1]: https://www.lnh-team.org/
The DS has you dealing with two cores you need to write a firmware for that have to communicate to do anything useful, a cartridge protocol to fetch any extra code or assets that wouldn't all fit into RAM at runtime, instruction and data caches, an MMU, ... And that's without mentioning some of the more complex peripherals like the touch screen and wifi.
All official games used the same firmware for one of the cores, a copy of which is embedded into every single cartridge ROM. There's some homebrew firmwares included in the respective SDKs, but they aren't well documented for standalone use.
Granted, all of the above isn't completely impossible, but if you think of how much code you'd need to get a simple demo (button input, sprite moving across the screen), especially for a beginner, the DS requires a nontrivial amount of code and knowledge to get started without an SDK. Meanwhile, you can do something similar in less than 100 lines of ASM/C for GBA.
None of this fixes the audio, but it sure gets damn close.
The issue with the sound isn't just the speakers - you could always use headphones, after all. The GBA only has the original GB's primitive PSG (two square waves, a noise channel, and a short programmable 4-bit waveform) plus two 8-bit PCM channels. 8-bit PCM samples are unavoidably noisy with lots of aliasing, and all sound mixing, sequencing, envelopes, etc. for those channels needs to be done in software, which tends to introduce performance and battery life constraints on quality, channel count, effects, and sample rate.
The SNES, by comparison, uses high-quality 16-bit 32kHz samples, and all the places on the GBA where devs may have had to cut corners are done in hardware: eight separate channels, no need for software mixing, built-in envelopes and delay.
Compare the SNES FFVI soundtrack to the GBA version; the difference is dramatic. Frankly, using high quality speakers or headphones just makes the quality difference more obvious.
Though there were some fits and starts there. The N64 for example is, from what I've heard, heavily library dependent and absolutely brutal to program bare metal (GPU "microcode" that was almost like programmable shaders v0.1); even the GameCube is a significant improvement for that kind of thing.
were about writing a program for the NDS
My only hesitation is the firmware update—-I simply prefer to keep my devices without changes like that.
Nice community at the time though, I made a pong clone where the main selling point was that you could switch between different "themes", and a bunch of people contributed some really nice custom ones to be included.
There is no reason to use a slot 2 cart nowadays and the state of the art for a slot 1 cart is the DSPico at https://gbatemp.net/threads/dspico-an-open-source-flashcart-... .
Thx
• Everybody has the same system (devs need to target only 1 environment)
• Boot straight into a programming environment
• Limited OUTPUT that enhances creativity without the internal limitations that hinder creativity: Like a limited numbers of colors, but no bitplane crap or having to do sprite multiplexing etc
• Online, ungated app store where anybody can publish, like itch.io
• Reasonable upgradability (not so much as to defeat point #1)
There are also open-source versions of the concept, like TIC-80.
The only thing missing is upgradability.