Advancemame- how do I configure a serial spinner?

[cgrieves]

Hi there, I've just added a spinner to my recently built Advancemame Cabinet. It's home-made from a hard drive bearing, DIY opto pickup with plastic-cup toothed wheel, and an Opti-PAC with a serial cable. All lashed together with a tuning knob from an old radio

The spinner works fine in DOS using Genius mouse drivers- I can invoke EDIT and move the cursor in the X-axis and ADVM shows the correct activity on mouse 0, axis 0.

The real problem is getting it to work in Advancemame (DOS). I've read the docs, which besides being confusing and unhelpful, don't see to apply to the latest version of Advancemame.

The docs mention "input_map[p1_dialx] mouse[0,x]" which just brings up an error, as does replacing the mouse[0,x] with mouse[0,0]. So it seems the p1_dialx parameter doesn't exist any more. I also tried "input_map[p1_trak] mouse[0,0]" which doesn't bring up any errors, but there's no response in games.

Has anyone got an in-English simple explanation of input_map configuration entries? I'm dying to play tempest!