public void handler() {
            /*UINT16*/int t, r;
            t=IMMBYTE();
            r = (m6800.b - t - (m6800.cc & 0x01))&0xFFFF;
            CLR_NZVC();
            SET_FLAGS8(m6800.b, t, r);
            m6800.b = r & 0xFF;
        }