devkitPro

How would I store 4 6 bit values into a 24 bit (a char and a short)value so i can later read each 6 bit value into a 1 byte value

Storing each 6 bits in a separate unsigned char will be faster and easier, at the cost of some 'wasted' memory. But, as suggested, many times it's better to waste some ...

an 'int' on a GBA/DS is 32 bits. You can use 'u8' or 'unsigned char' if you need to store only values from 0 to 255, and of course it will require less memory.
Speed is another matter, as you can't be sure that accessing smaller memory will require less time, since you should consider other details ...

In C you can make n-dimensions array just using square brackets pairs.
for instance declares a 3D array (matrix) with 10x30x50 elements, each one of the specified base type - 'int' in the example

WM: I hope at least they gave you that possibility. If you start developing the 'lib3ds', I'm sure many will happily help (I would!)

btw you should either use -pn or -pe

If you try using removing do you get it correct?

If you plan to use a 8px fixed width font, the faster approach is to use a text BG for that. If you want to use a variable width font, I guess you will be forced to render them on a bitmap BG. There can be other options in between

AFAIK, to develop a library you should at least have enough knowledge on the hardware internals.
AFAIK (and if I'm wrong I'd like to read some details...) there's still no such knowledge. (well, we know there's an ARM11 and a PICA200 etc etc but we still don't know which hardware registers to point ...

If you write to OAM or OAM_SUB, you're updating sprites 'immediately' (meaning in the current frame) while using libnds APIs, you're 'preparing' OAMs for an update that you'll do later, probably right when VBlank starts. This is however not really related to performance, but it is surely related to ...

I haven't got a chance to test this by my own... on my NDS Lite the RealTimeClock example works perfectly but I've been in touch with some guy who said the clock doesn't go on on his 3DS. He suggests that IRQ7 doesn't get triggered (which is likely to be possible, if the clock hands doesn't move ...