SHA-0 was NSA's original Secure Hash Algorithm (SHA). Secure Hash Standard (SHS). (: And if you don't know what NSA is you are behind the times in cryptography. :)
SHA-0 was defined in FIPS PUB 180, 11 May 1993, it was replaced by SHA-1 is defined in FIPS PUB 180-1, 17 Apr 1995.
SHA produces a unique message digest given a stream of bits. The standard is actually defined in terms of bits, but most implementations only handle a stream of bytes. This implementation will take data in as either bits, bytes (8 bits), words (16 bits) or long words (32 bits) at a time. (I know that this may not agree with the underlying sizes on your machine, but I had to call it something.)
SHA Definition of a message Digest.
There is also a Unix Tar file of this code, and compressed version.
This page is http://www.cc.utah.edu/~nahaj/ada/sha/sha-0/ © Copyright 2000 by John Halleck, All Rights Reserved. This snapshot was last modified on August 23rd, 2000