Update: here is a fancy astdlx adapter I built a few of which contains a vector flip circuit, an attempt at equalizing out the audio, some configuration jumpers, LED etc. I did this originally for myself and just for fun, but if there is enough interest I could run a production run of these until the counterfeiters steal and copy it like they always do.

The original poor mans design is below

Poor mans design Click image for larger closeup
Step 1 Materials needed. 44 pin edge connector 56 pin jamma finger	Step 2 Cut 56 pin jamma finger down to 44 pins.	Step 3 With a Marker place an "X" on pins 12(N), 13(P), and 15(S) a little bit off center from the middle of the finger. Label the edge connector for parts side.
Step 4 Drill 1/8" holes through the finger at the places marked in step 3. 1/8" is wider than the finger trace, goal is to break the trace and provide a hole to thread the wires through.	Step 5 Solder 44 pin finger to the edge connector. Make sure you match up the parts side.	Step 6 Cut and solder 6 short wires to the edge connector tabs for the 6 traces cut by the holes. Feed the wires through the corresponding hole.
Step 7 Another pic of Step 6. Wires should be around 1" long.	Step 8 Cut the wires as to minimize any excess. Solder the other end of the 6 wires to the opposite side of the finger board.	Step 9 Close up of final adapter. Congrats!