Found the answers on another forum and from dinking around but I thought I would share them here for anyone who comes looking.
1. You need to run from COM-1 on the computer which is the 9 pin plug on the back of the mother board on most modern computers.
2. You DO NOT need a fancy “Null Modem” adaptor, just a simple serial cord 9 pin to 25 pin, with a Male / Male adaptor
3. You well need to correctly set up the DNC programming in the Anilam GXM controller. This can be done pretty easily with CNet which is a FREE download from Cadem.
To properly test the DNC function of the Anilam GXM you need to jumper several pins together. I just bought a simple DB-25 jack at radio shack and soldiered the wires accordingly. 2 to 3, 4 to 5, and 6 to 20.
Rick at Anilam said if it didn’t pass the test then it must be the 503 board or the wiring harness. A quick check with an oscilloscope showed it to be the Motorola MC68681P chip, aka 8 bit Serial Data interface chip. Since it is socketed it is relatively easy to replace