Hmmm...interesting.
I remember my raycaster flickering like crazy until I got double-buffering working.
Are you doing anything special?

oooh I see, that explains why sprites won't flicker while the map is getting displayed. I assume they're drawn at the same time as the map, right?

Aaah I see ^^

Nice job on the emus regardless, though

I've got the buffering all figured out, but it seems like nmath.h is missing from the skeleton. When I tried to compile a program using line, I got an error saying nmath.h doesn't exist.

I am assuming that the abs( function is from nmath.h (that is the only one that did not "exist").  A simple solution would be to write your own abs( function, get rid of the "#include "nmath.h"" at the top and add your own abs( to the header.  Here is a very basic one I wrote.  I am sure that a smaller and faster version could be written:

int abs(int x) {
if (x<0) {
x*=-1;
}
return x;
}

Declare a sprite like this:

              char sprite[32]={15,15,15,0,0,15,15,15,
                                15,15, 0, 0,0, 0,15,15,
                                15, 0, 0, 0, 0, 0, 0,15,
                                 0 , 0, 0, 0, 0, 0, 0, 0};
The number of elements in the array should be equal to the height*width of the sprite.  Each element should be the color you want the pixel to be.  Bwang's sprite drawing functoin takes the syntax:

void sprite(char* scrbuf, char* sprite, int x, int y, int w, int h);
Where scrbuf is the buffer, sprite is the spite you want to draw, x is the x coordinate of the sprite, y is the y coordinate, w is the width, and h is the heigth

If you read my first, unedited post, please disregard it b/c some of the info was wrong.

Unfortunately, apcalc, I read you unedited post, but now it's all sorted out, and I can play pong on my nspire. 

Thats great to hear! I was used to the way you draw sprites on the 89, so I just assumed it was the same way. Feel free to ask if you have any more questions!

I've been having a very odd bug with an Nspire C program.  Every time I exit the program pressing ESC (for some reason my loss detection dosen't work) the calculator reboots (the emulator says "CPU Reset") (I have only tried this on the emulator).  All of the other ASM programs I have on the emulator (ncaster, gbc4nspire, ndless demo) work correctly. Also in my code you will see that I have the loss detection commented out.  When I have this part of the code, the calc reboots right after the dialog box displays.  Here is the code:

#include <os.h>
#include "utils.h"

asm(".string \"PRG\"\n");

int main(void) {
  char marker[32]={15,15,15,0,0,15,15,15,15,15,0,0,0,0,15,15,15,0,0,0,0,0,0,15,0,0,0,0,0,0,0,0};
  short int leftx,length,ycord,lengthchange;
  float spritepos;
  char* scrbuf = (char*) malloc(SCREEN_BYTES_SIZE);
  char* tempbuf = (char*) malloc(SCREEN_BYTES_SIZE);
  showSimpleDialogBox("TI-Nspire Tunnel","TI-Nspire Tunnel\nWritten in C by Danny Clark\n\nUse the arrow keys to control ship");
  clearScreen();
  leftx=120,length=120,lengthchange=1000,ycord=0;
  spritepos=180;
  clearBuf(scrbuf);
  for(ycord=0;ycord<SCREEN_HEIGHT;ycord++) {
  horizontalline(scrbuf,0,leftx,ycord,0);
  horizontalline(scrbuf,leftx+length,319,ycord,0);}
  sprite(scrbuf,marker,150,236,8,4);
  refresh(scrbuf);
  leftx=120;
  ycord=0;
  while (!isKeyPressed(KEY_NSPIRE_ESC)) {
  if (isKeyPressed(KEY_NSPIRE_LEFT)) {
  sprite(scrbuf,marker,spritepos,236,8,4);
  spritepos-=0.7;
  sprite(scrbuf,marker,spritepos,236,8,4);}
  if (isKeyPressed(KEY_NSPIRE_RIGHT)) {
  sprite(scrbuf,marker,spritepos,236,8,4);
  spritepos+=0.7;
  sprite(scrbuf,marker,spritepos,236,8,4);}
  sprite(scrbuf,marker,spritepos,236,8,4);
  lengthchange--;
  if (lengthchange==0) {length--;lengthchange=1000;}
  scrollScreen(scrbuf,tempbuf,1);
  horizontalline(scrbuf,0,leftx,ycord,0);
  horizontalline(scrbuf,leftx,leftx+length,ycord,15);
  horizontalline(scrbuf,leftx+length,319,ycord,0);
  sprite(scrbuf,marker,spritepos,236,8,4);
  refresh(scrbuf);
  //if (getPixel(spritepos-1,ycord-3)||getPixel(spritepos+8,ycord-3)) {free(scrbuf);free(tempbuf);return 0;}
  }
free(scrbuf);
free(tempbuf);
return 0;
}


Also, I don't have the code for the function horizontal line there but I am sure that is not the problem because it was defined and used well before I experienced this problem.  This program was working fine earlier today, but I made a few small additons and now I have no idea what is causing this.  Also, I made one small modification to the function "scrollScreen(".  I changed the two signs in the function (+ to - and - to +) to make the screen go down instead of up.