Generate pseudo-random 16 bit number

[2kaud]

I want to generate a 16 bit pseudo-random number using only 16 bit variables. This will then be used to generate pseudo-random numbers in the range mn to mx (typically 10 to 700). I've come across this code in c:

short x = 3030;
 
unsigned xorshift( )
{
    x ^= x << 7;
    x ^= x >> 9;
    x ^= x << 8;
    return x;
}

short getrnd(short mn, short mx) {
	short r = xorshift();
	short mod = mx - mn + 1;
	r = r % mod;
	r = r + mn;
	return r;
}

The language is un-important. I'm more interested in the algorithm used. The algorithm needs to be fairly simple and quick. This seems to be ok but is there a better algorithm than this please?