Try http://geocities.com/satfiles2/html/conax_.html. I have tried to get advice of how to program my commercial card with this commercial card upgrade but have not had any joy. I think it may be due to not using a proper dos box to do the programming (Windows 2000).
If you get any joy with this, please post.
BTW, I have read some posts on the forum located at the above site who have re-programmed their cards with this upgrade and it works perfectly.
If anyone else has any ideas, a reply would be appreciated.