Is it possible to cross-connect two AUI ports without transceivers?

Solution 1:

Yes, it can be done.

Connect pin 3 (TxD-A) on each end to pin 5 (RxD-A) on the other. Connect pin 10 (TxD-B) on each end to pin 12 (RxD-B) on the other. On each end, connect pin 6 (Vc) to pin 9 (Collision Detect / Control In B). Connect the two ground shields together.

Note that while this usually works, it does technically violate the specifications, so it's an "at your own risk" kind of thing. Note also that this is not safe if both devices are not connected to the same grounding point.

Solution 2:

Pick up a used DELNI. And learn some new swear words for when you're latching and unlatching the &%$# !@!@! (*&^% sliders on the AUI cables.