It really depends on how the files were transferred over to AIX in the first place.
If it is the porting project I think it is, I’m familiar with the database conversion but I wasn’t involved with any of the non-database data.
I suspect that FTP was probably used to transfer the datasets to AIX. You need to find out whether an EBCDIC -> ASCII translation was performed at the same time. If you’re lucky, someone from the project team is still around and can help you out. If you are really, really lucky, the process was documented and you can look it up yourself.
The FTP ASCII translation works great if you are only dealing with alphanumeric data but the wheels fall off when packed or binary fields are present. As FTP has no understanding of the data structure, it simply converts as if the field is an alpha and turns each byte into its ASCII equivalent - not very useful. It might be possible to do a reverse conversion but I’m not sure how the FTP ASCII conversion handles non printing characters…
If it was a binary transfer then your packed and binary fields will be fine but you are going to need to translate the alphanumerics. If we are looking at fixed length records, it might be as simple as reading into a redefined binary variable, setting up your own translation table and doing a series of EXAMINE TRANSLATE USINGs. You’d probably need to define the workfile in your program as UNFORMATTED.
Try and have a look at the actual data with some sort of hex viewer to get an idea of what you are dealing with.
Of course in an ideal world, the best method is to convert all the packed & binary fields to alphanumeric before the transfer. Back in the real world where the migration budget isn’t infinite, pragmatic decisions are often made to not bother converting the myriad of files that are unlikely to ever be read again and to deal with the situation if/when it ever arises in the future (using someone else’s budget of course).