FXPF

File Format
Name	FXPF
Ontology	Electronic File Formats Archiving FXPF
Extension(s)	special
Released	≤1993

FXPF is the signature of what is presumably a Microsoft binary patch file format. It was used in some MS-DOS 6.x upgrade ("Step-Up") packages.

Identifiers

The last character of the original filename extension is replaced by an uncommon character such as "#", "^", or "@".

Identification

Files begin with ASCII "FXPF", possibly always followed by bytes 0x00 0x00.

Sample files

• DOS62.ZIP - MS-DOS 6.2 Step-Up
• 622_STEP.ARJ - MS-DOS 6.22 Step-Up