LDArc and LDIFF

File Format
Name	LDArc and LDIFF
Ontology	Electronic File Formats Archiving LDArc and LDIFF
Extension(s)	.lzd
Released	≤1989

LDIFF (or LDiff) is a differential compression utility for DOS, designed for binary files. It was developed by Kazuhiko Miki (also known for LArc). Its native file format is .LZD.

Identification

LZD files created by LDIFF v1.20 have "-LD6-" at offset 2. The format has some similarity to LHA, but is not compatible with it.

Version 2.00 uses a different LZD format, which has not been investigated. It also seems to be able to create self-running patches in COM format.

Software

• LDIFF v1.20 · source code
• LDIFF v2.00 (Japanese): FreeWare Collection 2 / フリーウェアコレクション2 → FreeSoftwareCollection2pd199x-jp.img → ms_dos/ldiff/ (or at DiscMaster)