Well, I was going to post about this when I had this complete, but it appears hoffa beat me to the punch

Anyways, I have a (mostly ) complete CHIP8 interpreter written in C.  I started this last Friday and really haven't touched it since (mostly because I've been out of town).  Ironically, the only problem I'm really having is working with the Nspire's screen, so if someone could look at my code and see what I'm doing wrong/give me some pointers* in the right direction, that would be great.

I am using the setPixel routine from the ndless example source code.  chip->LCD is a 2,048 (64x32) byte array with each element presumably holding a 1 if the pixel is set and a 0 if it is reset.
if (chip->drawflag)
{
for(int row = 0; row < 32; row++)
{
for(int col = 0; col < 64; col++)
{
/*ignore the comments if you must
                                                        for(int rowoffs = 0; rowoffs < 8; rowoffs++){
for(int coloffs = 0; coloffs < 8; coloffs++){
setPixel(col + coloffs, row + rowoffs, (0x0F * (chip->LCD[32*row + col])) ^ 0x0F);
}
}*/
setPixel(col, row, (0x0F * (chip->LCD[32*row + col])) ^ 0x0F);

}
}
}
Now, I think this is all fine and dandy, but I get something that looks like garbled junk when trying to run SPACEINVADERS (see attached pic).



Can anyone help?  Thanks in advance.

MM

*Pun so totally intended.

You can try some games in your browser here: http://chip.emulationcollective.com/

From what I see, it features a small monochrome screen (the pixels are oversized so it looks decent) and a hex keypad.

Oh ok it's SCHIP8?  Thanks for the correction. Also I think that one had a larger screen, right?

Btw I wish the new posts list showed topic descriptions.

I am using the setPixel routine from the ndless example source code.  chip->LCD is a 2,048 (64x32) byte array with each element presumably holding a 1 if the pixel is set and a 0 if it is reset.

Code: [Select]

if (chip->drawflag)
{
for(int row = 0; row < 32; row++)
{
for(int col = 0; col < 64; col++)
{
/*ignore the comments if you must
                                                        for(int rowoffs = 0; rowoffs < 8; rowoffs++){
for(int coloffs = 0; coloffs < 8; coloffs++){
setPixel(col + coloffs, row + rowoffs, (0x0F * (chip->LCD[32*row + col])) ^ 0x0F);
}
}*/
setPixel(col, row, (0x0F * (chip->LCD[32*row + col])) ^ 0x0F);

}
}
}
Now, I think this is all fine and dandy, but I get something that looks like garbled junk when trying to run SPACEINVADERS (see attached pic).

Shouldn't it be setPixel(col, row, (0x0F * (chip->LCD[64*row + col])) ^ 0x0F); ? Or am I wrong?

OK, here's a small update

v0.2a.12.5.18 - 5/18/12
* fixed a bug in keypress handling that caused keys that had already been pressed to continue to be pressed.
* added support for the Casio PRIZM

Bugs:
Problems with the way sprites are being drawn - not quite sure what it is though

TODO:
Optimize this to make it faster
Implement SCHIP instructions

Enjoy!