Does anyone either have a link to or know of somewhere where I can get the DBD file specs for INFORMIX 3.3?

I have all the dbd and dat files which were backed up nightly ... I need to recover the data from an old Xenix box circa 86 and move into another RDB but the going is slow ... the data is stored in fixed format so I could manually determine the field sizes but that would take some time considering there are several hundred fields across many tables and DB's ... so far I have figured out how to recover the Table and Field names out of the dbd files but still struggling with deciphering the Field details.

I have the Informix Manual which describes the data types just not sure how they coded these types in the dbd file. Any Help would be appreciated.