pfs:Write was a simple word processor created by Software Publishing Corporation (SPC) in the early days of desktop computing. It was intended for DOS systems, but Apple II versions were also released.
The last version, Professional Write 3.0 for DOS, was released in 1994. Professional Write Plus was developed for Windows 3.x in 1991.
First 4 bytes are hex values
42 00 06 00 or
42 00 0C 00 and have an EOF byte of