AMD Lance Am7990 IEEE 802.3 Ethernet Media Access Controller (MAC) controller were introduced in 1985. Its architecture is the basis for AMD's PCnet Family of highly integrated single-chip Ethernet controllers. The one exception is the Am79C940 MAC.The Am7990 chip was fabricated in NMOS technology and has no integrated Manchester encoder/decoder (ENDEC) nor does it have an integrated 10BASE-T transceiver.