TCO-745VC TCO-745VC(6.176MHZ) TCO-745VC-12.288MHz TCO-745VC32.768MHZ TCO-754B7-20.000000MHZ TCO-754QW-49.15200MHz TCO-756B-60.000000MHZ TCO-756BVX7 TCO-756BVX7-38.880MHZ TCO-756DVX7