Simple OS writing to screen help

HI guys

I found this article on how to create your own simple OS that just prints to screen, I know its pretty lame but I am trying to get it to write one more line to the screen but it just wont do it. Here is the kernel.c source, there are 2 more files, kernel.h and screen.c
I have (hopefully) attatched the other 2 files. I placed a comment about 15 lines down which explains what I did.

Code:

#include "kernel.h"

int strlen(string str);
void dec2bin(dword decimal, int prefix);
void drawdesktop(byte ch, char fore, char back);
void drawwindow(string title, int xpos, int ypos, int width, int height, char fore, char back);


void kernel(void) // kernel entry point
{
	drawdesktop(177, COLOR_WHITE, COLOR_BLUE);
	drawwindow(" Simple OS Example - by Napalm ", 4, 4, 72, 16, COLOR_LTWHITE, COLOR_BLUE);
	putsnocr("Welcome to this example! ");
        /* I put another putsnocr line here but it didnt show up only "Welcome to this example" showed  */
	hidecursor();
	
	dword value = 0xDEADBEEF;
	while(1){
		// display value in decimal
		gotoxy(6, 9);
		dword decimal = value;
		char base[10];
		int i = 0;
		while(decimal > 0){
			base[i++] = '0' + (decimal % 10);
			decimal /= 10;
		}
		while(i-- > 0) putch(base[i]);
		
		// display value in hex	
		gotoxy(6, 10);
		putsnocr("0x");
		for(int i = 28; i > -1; i -= 4){
			byte nibble = ((value >> i) & 0x0F);
			if(nibble < 10) putch('0' + nibble);
			else putch('A' + (nibble - 10));
		}
		
		// display value in binary
		gotoxy(6, 11);
		dec2bin(value, 32);
		value++;
	}
}

int strlen(string str) // simple string length
{
	string end = str;
	while(*end++);
	return (end - str);
}

void drawdesktop(byte ch, char fore, char back)
{
	// clear screen with foreground and background
	// and also with desired character
	settextcolor(fore, back);
	cls(ch);
}

// decimal to binary
void dec2bin(dword decimal, int prefix)
{
	dword j = 0;
	for(int i = prefix; i >= 0; --i, j = ((decimal & (1 << i)) >> i))
		if(prefix || j) prefix = putch('0' + j);
}

void drawwindow(string title, int xpos, int ypos, int width, int height, char fore, char back)
{
	int xextent = (xpos + width - 1), yextent = (ypos + height - 1);
	// draw window
	for(int y = ypos; y <= yextent; y++){
		settextcolor(fore, back);
		gotoxy(xpos, y);
		if(y == ypos){ // draw top caption bar
			settextcolor(COLOR_LTYELLOW, COLOR_RED);
			for(int x = xpos; x <= xextent; x++){
				if(x == xpos) putch(213);
				else if(x == xextent) putch(254);
				else putch(205);
			}
			gotoxy(xpos + ((width - strlen(title)) / 2), y);
			putsnocr(title);
		}else if(y < yextent){ // draw middle lines
			for(int x = xpos; x <= xextent; x++){
				if(x == xpos || x == xextent) putch(179);
				else putch(' ');
			}
		}else{ // draw bottom edge
			for(int x = xpos; x <= xextent; x++){
				if(x == xpos) putch(192);
				else if(x == xextent) putch(217);
				else putch(196);
			}
		}
	}
	// draw vertical shadow
	for(int y = ypos; y <= yextent; y++){
		gotoxy(xextent + 1, y + 1);
		settextcolor(COLOR_WHITE, COLOR_BLACK);
		putch(177);
	}
	// draw horizontal shadow
	for(int x = xpos; x <= xextent; x++){
		gotoxy(x + 1, yextent + 1);
		settextcolor(COLOR_WHITE, COLOR_BLACK);
		putch(177);
	}
	// position cursor inside window
	gotoxy(xpos + 2, ypos + 2);
	settextcolor(fore, back);
}

Can anyone please explain whats wrong?

Cheers

HLA91

I wouldn't call that your own operating system . . . it's just an ncurses program as far as I can tell. An operating system is a lot more complicated.

Anyway . . . check out the name of your function.

Code:

putsnocr("Welcome to this example! ");

It's not printing a newline (CR). That would mean that at the very best, your message would appear right after this one -- and I suspect that the code might be overwriting that part of the screen. You'll probably want to move the cursor before printing a new string. I haven't really used ncurses, but I think move() would do the trick, or a function like mvputsnocr(). Something like that.