OPAQue

oPAQue (also called PAQ) is a compressed archive utility for DOS, and its associated file format. It was developed by Dmitry Dvoinikov, and distributed as freeware. It was originally named PAK.

Disambiguation
Not to be confused with other formats named PAQ or PAK.

Identification
More research needed.

IDArc interprets the first 8 bytes of a file as four 16-bit little-endian integers, adds them together, and identifies it as oPAQue if the low 16 bits of the sum equals.

oPAQue files have been observed to start with, which is consistent with that algorithm (sums to  ).

But this website reports, which does not quite work -- it sums to.

Software

 * [ oPAQue v1.0]

Links

 * 2003 archive of oPAQue website
 * Web page at tpi.osdn.jp