public void nega()
    {
        int r;
    	r = -m6809.a & 0xFFFF;
    	CLR_NZVC();
    	SET_FLAGS8(0,m6809.a,r);
    	m6809.a = r & 0xFF;
        if(m6809log!=null) fprintf(m6809log,"M6809#%d nega :PC:%d,PPC:%d,A:%d,B:%d,D:%d,DP:%d,U:%d,S:%d,X:%d,Y:%d,CC:%d,EA:%d\n", cpu_getactivecpu(),m6809.pc,m6809.ppc,m6809.a,m6809.b,getDreg(),m6809.dp,m6809.u,m6809.s,m6809.x,m6809.y,m6809.cc,ea);
 
    }