Homebrew A software (slot-1) to enlarge gba games' image (slot-2) on DS/DS Lite

[Nikokaro]

Hi everyone.
I know this question has already been asked by others, but the answers given have not satisfied me, also because they come mostly from simple players, and not from programmers, developers, hackers or subject matter experts.

I, like many others, would have always liked to play gba games (from gba cartridge/slot2 flashcart) on DS/DS Lite with the image scaled to fill the screen (with or without maintaining the aspect ratio).
Would it be technically possible to do this, using special software launched from DS (Slot1) flashcart? Would anyone experienced in this matter be interested in tackling this challenge, to the delight of many players (or so I think)?

Usually it is said that the image would be deteriorated, pixelated and unsatisfactory, but this is a subjective judgment, and anyway it could be remedied by applying a simple graphic filter (as is already done for Lameboy/ Gameyob).
Maybe, but I'm not sure (I say this as an ignorant of the subject), the games would slow down a bit; if so, couldn't this be remedied by skipping some frames?
Wouldn't anyone else here, who owns a DS and a gba flashcart, like to play gba games full screen, or is it just a fixation of mine?

Don't talk to me about DSi XL with GBARunner2 because I already use them but the compatibility of the games is not perfect, many roms are faulty and many hacked roms don't work at all (e.g. Pokémon Hacks or PrBoom's Megawads ported on GBA).

I hope I have explained myself, despite my limp english. Thanks.

 

[FAST6191]

GBARunner is unworkable for you but tile blurring, skewed aspect ration and frameskip is acceptable? Curious.
You are not the first to ask for such things, I never got it myself but I have probably spent far too long editing video and images to the point where I can spot a comb in a single frame at a dozen paces and thus probably broke my options on that front.

Traditionally the only way to run GBA ROMs in any kind of sane fashion (I was stunned to see the proof of concept thing) from the DS slot in DS mode is to have the flash cart itself run an emulator (iplayer, ismm, dstwo) as the DS slot is way too slow to reliably do GBA games, the GBA slot but notably quick compared to what many would expect from the era (see also why GBA flash carts are expensive and why the GBA slot supercards, which skimped there, need all manner of extensive patches to even approximate something useful).

DS fishing code from the GBA slot, acting as some kind of interpreter/hypervisor, and having it act as an overlay... that is more interesting. Few investigated that as having a GBA flash cart was generally all that people really wanted.
It would be a lot of effort, and nobody is putting that kind of effort into DS stuff today. You would be better off seeing whatever the upcoming FPGA based systems are doing, doing some kind of hardware level screen scaling (or replacement -- make one of those GBA macros actually mean something maybe, though I might twist the TV out stuff into something).

 

[Nikokaro]

@FAST6191 , Finally a technical and precise explanation, from an expert, competent person, who understands the subject (of which I have esteem, and in truth I hoped he would answer me) and in an english quite simple and understandable for me (as opposed to yours other answers much more technical and sophisticated), and I thank you for this, as well as for having bothered to answer these questions for you perhaps too trivial and naive.

Well, you have shattered my dreams and my fondest hopes...