Binary II

File Format
Name	Binary II
Ontology	Electronic File Formats Archiving Binary II
Extension(s)	.bny, .bqy
Wikidata ID	Q105854138

Binary II (or Binary ][) is a file format used for storage and transmission of Apple II files which encodes the file attributes (from any of the various Apple II or III filesystems, such as DOS 3.3 and ProDOS) in a header, allowing the file to be reconstituted at the other end of a transmission with all the directory information intact.

The usual file extension was .bny (which sometimes got pronounced as "bunny"), while versions compressed with Squeeze were commonly found with .bqy extensions.

Identification

A Binary II file starts with bytes 0x0a 'G' 'L', and the byte at offset 18 is 0x02.

Specifications

• Apple II File Type Notes $E0/8000: (text) · (HTML) · (PDF - archived)
• ARCHIVE FORMATS AND DATA, by Raymond Clay - "BINARY ][" section

Software

• NuLib, NuLib2, NufxLib
• NuLib v3.24 (DOS software)

Note: Many Binary II archives contain just a single file, which can be recovered in a crude way simply by deleting the first 128 bytes of the archive.

Sample files

• https://telparia.com/fileFormatSamples/archive/binary2/