Regarding the color palette for icons in ps1 save games...
You said there are 4 bytes for each pixel, right ? well, i have not seen myself so this is only speculation
But depending of is there is support for tranparency then this bytes are RGBA (the last "A" = alpha or transparency)
Better dont do changes manually there, because after the changes you need to correct the XOR code (im not sure if there is a XOR code for every frame or every block, you know better than me, but you know wich one i mean)
The best way do understand this is by using the "icon editor" inside MemcardRex... make your changes, save the file and compare (also if transparency is supported there must be a transparent color available in the editor)
What i understand about the "magic" MC or SC... is MC is using only for the header (first block)
Then SC is used for the resting blocks when are used
But it can be a save data that occups several blocks... this info is stored in the first block of this save, right ?... i mean... the second and next blocks can be used completly. Only the first one has a "header" that marks the length of all ?
With animated icons that needs more than 1 frame.... the point is the data starts after the last frame used, right ?
If the icon only has 1 frame (not animated)... the data starts in frame 2
If the icon has 2 frames... the data starts at frame 3
If the icon has 3 frames... the data starts at frame 4
Is this way or im wrong ?
The memory card adaptor.... yes i suppose the system manages it exactly as a .VM1 or .VM2 depending of the card you insert
Is very usefull to simplify the conversions between formats, it makes the things faster and can be used in a official ps3 in any firmware
If you think in it.... all this its so insecured for sony that i doubt any of the "old" ps2 homebrew will work... i bet the emulators uses a "white list" of sony signed apps (there must be not too much)... and the rest are "blocked"
But there is a lot to play with this, e.g:
Use "independence exploit installer" configured to a DISC_ID of a "ps2 classic" game and to boot ulaunch.elf... then when you boot the game the exploit is triggered loading ulaunchelf = win
Btw... can you try to export from PS3 a single PS1 game save to a real PS2 memory card ?
I wrote in the wiki that PS1 saved games can be stored in PS2 memory cards... i remember this from lot of years ago but im not 100% sure now
Can you verify it ?
I readed something about this adaptor compatibility in old firmwares, you are right but i dont remember exactly
It was something like previously there was no option to export (only import supported)
This... or the opposite...