Because I haven't figured out an intelligent way to do it, so I just refresh the screen 20 times each iteration of the loop.

Edited the first post and skeleton.zip to include the new text routines. I've found them rather useful, despite their limited abilities, so they've been integrated into skeleton.zip for the moment.
bsl and I (on United-TI) have found how to list files. This seems useful, so dirlist.h has been placed into skeleton.zip as well.
The syntax for dirlist() is:
int dirlist(char* path, char* pattern, char** result)
path: the folder you are looking in, e.g. "/documents/examples"
pattern: a search pattern, e.g. "*.tns"
result: a pointer to a char* (i.e. a list of strings) that will store the resulting filenames

return value: the number of files found


Here are some text output routines. The character map is courtesy of Armael on United TI, and the routines are inspired by his, too. Right now, all I have is a function akin to TI-BASIC's text() function - pass it a string and some coordinates, and it will draw it to the designated screen buffer.
There used to be more, but no program loader -> no static variables -> a real console becomes incredibly unwieldy I thought about passing pointers to the cursor coordinates to the functions, but that's a bit too unwieldy.

File descriptions:
charmap_8x12.h: the character map.
screen.h: contains functions putChar and drawStr.
stdarg.h: variable-length argument list header.
string.h: some string functions

Do we have entry points for vsprintf()? That would make writing a printf() so much easier.

Enjoy! And remember, this is a very in-progress set of routines, so don't use them for anything fancy.

No, not a spambot.
The OP mentioned the site in his post.

What? So now they're forcibly ejecting anyone who doesn't agree with them?

I messed around with your code, and discovered that you are doing something really weird in maze.c, which messes up the external variables in testlevel.c. The Nspire's support for global variables is pretty delicate at the moment, so if something doesn't work, try moving the contents of testlevel.c into main().
You probably want to have generate() take paramenters, so it should look something like:
void generate(int* maze)
where maze is the array you are writing to.
Oh, and random thought: I feel slightly happier about Ncaster now. With a map that dense, I was expecting it to be unbearably slow, but apparently that's not happening .

Your height array is incorrect, I think. The rows have been shifted a bit, so now the spaces on your map are getting the wrong height data.