ascii-converter | use Ascii converter that could convert | Computer Vision library

First, PIC X is not Unicode in COBOL.

Quoting myself from here...

It is common for mainframe data to include both text and binary data in a single record, for example a name, a currency amount, and a quantity:

Hopper Grace ar% .

...which would be...

x'C8969797859940404040C799818385404040404081996C004B'

...in hex. This is code page 37, commonly referred to as EBCDIC.

[...]Converting to code page 1250, commonly in use on Microsoft Windows, you would end up with...

x'486F707065722020202047726163652020202020617225002E'

...where the text data is translated but the packed data is destroyed. The packed data no longer has a valid sign in the last nibble (the lower half of the last byte), the currency amount itself has been changed as has the quantity (from decimal 75 to decimal 11,776 due to both code page conversion and mangling of a big endian number as a little endian number).

Likely your data was code page converted on transfer from the mainframe. If you know the original code page and the code page it was converted to, then you might be able to unscramble the packed data.

I say might because, if you're lucky, the hex values you have will have been mapped one-to-one with hex values in the original code page. Note that it is common for both EBCDIC x'15' and x'0D' to be mapped to ASCII x'0D'.