I need a MAC controller to handle converting between AUI and 10BASE-T.
I hope anyone can help.

The AUI to 10BASE-T converter is hardware (to my suprise still available from a quick google search, haven't seen one in years :-)). The MAC (such as the opencores 10/100 MAC) would drive the PHY in front of the AUI.

Peter Van Epp

Thanks ... will it be possible to implement the AUI to 10BASE-T converting in a FPGA?

No. The main piece involved is the transformer to the RJ45 jack neither of which
have to do with the fpga. I somewhat suspect you are asking about the wrong thing. An
AUI connector is very old (at least 15 years or more) and 10BASE-T only. I somewhat
suspect you are looking for an ethernet PHY such as this one from Enterpoint:

http://www.enterpoint.co.uk/moelbryn/modules/ethernet_phy.html

which takes the output from the MAC in the fpga and converts it to the appropriate
signals out the RJ45 connector. I'd be fairly suprised at an fpga card having an AUI
connector because it is so limited (10 meg only, the PHY listed is 10/100) and so old.
If this doesn't help some more information on what you are trying to connect is probably
in order.

Peter Van Epp