mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-08-17 03:29:09 +00:00
49 lines
1.0 KiB
C
49 lines
1.0 KiB
C
|
|
#include <nes.h>
|
|
|
|
const unsigned char TEXT[]="Hello PPU!!!!";
|
|
|
|
const unsigned char PALETTE[]={0x1, 0x00, 0x10, 0x20}; // blue, gray, lt gray, white
|
|
|
|
void main (void) {
|
|
unsigned char index; // used in 'for' loops
|
|
|
|
// if we've just powered on,
|
|
// wait for PPU to warm-up
|
|
waitvblank();
|
|
waitvblank();
|
|
|
|
// turn off screen
|
|
PPU.control = 0x0; // NMI off
|
|
PPU.mask = 0x0; // screen off
|
|
|
|
// load the palette
|
|
// set PPU address to 0x3f00
|
|
PPU.vram.address = 0x3f;
|
|
PPU.vram.address = 0x00;
|
|
for (index = 0; index < sizeof(PALETTE); index++) {
|
|
PPU.vram.data = PALETTE[index];
|
|
}
|
|
|
|
// load the text into VRAM
|
|
// set PPU address to 0x21c9
|
|
PPU.vram.address = 0x21;
|
|
PPU.vram.address = 0xc9;
|
|
for (index = 0; index < sizeof(TEXT); index++) {
|
|
PPU.vram.data = TEXT[index];
|
|
}
|
|
|
|
// reset the scroll position to 0
|
|
PPU.scroll = 0;
|
|
PPU.scroll = 0;
|
|
// reset the PPU address to 0x2000 (frame start)
|
|
PPU.vram.address = 0x20;
|
|
PPU.vram.address = 0x00;
|
|
|
|
// turn on the screen
|
|
PPU.mask = 0x1e;
|
|
|
|
// infinite loop
|
|
while (1);
|
|
}
|