This tool is used to determine various CRC values for a binary file. These can be used to precisely identify a file with greater confidence. Where no applicable checksum exists in a Kickstart ROM image, I use the "CRC-32 2" value to identify it (this is the same CRC-32 value used by all "Zip" tool variants.) If no details exist in this column, that indicates that no sample is currently available for study, although the ROM is believed to exist. Here is the readme for GetCRC 1.19 (presented verbatim):
Short: V1.19 calculates different checksums Author: stoecker@epost.de (Dirk Stoecker) Uploader: stoecker@epost.de (Dirk Stoecker) Version: 1.19 Type: dev/c This program has 2 aims. First it allows to calculate different types of checksums including CRC and much other types and thus allows to identify a given checksum. Second its source code shows how to create these checksums, so they can be used in own projects. It is plain and portable ANSI-C code. The program is called like "GetCRC" and prints the resulting checksums of this file. Text modes aren't supported, but it always uses binary mode. The file must fit completely in memory. These are no restrictions to the algorithms, but are restrictions of using all of them in one program. When choosing own algorithms, I suggest usage of "CRC-32 2", which is one of the reliable standard algorithms. In the output the lines with (M/I) always have two numbers, where the first is Motorola byte ordering and the second Intel byte ordering. The Word and Longword checksums can't be calculated, if the file size isn't a multiple of 2 or 4. GetCRC calculates the checksum of the largest part, which is such an multiple and prints the additional bytes after the checksum. Depending on the checksum generator such bytes are either ignored, added to the higher bytes or added to the lower bytes of the result. Here is the list of currently supported checksums. It also includes a list, where these are used. Tell me other places, so I may update this list. Send me new algorithms, source comments, better or different calculation methods, ... CRC-16 1 : PCompress2, Arc, DMS, ProPack, LhA, Zoo, Shrink CRC-16 2 : CCITT, XModem, LU CRC-16 3 : Donald Kindred's CRC CRC-16 4 : old Zoom, CompDisk CRC-32 1 : Olaf Barthel's CRC, PCompress, Zoom 5, LhPak CRC-32 2 : Zip, GZip, LZX, RAR, Arj CRC-32 3 : Brik (Binary mode), Ace CRC-32 4 : GPatch (old) CRC-32 5 : BZip2 CRC-32 6 : BZip2 inverted CRC-32 7 : chksum utility CHS-16 1 : PowerPacker Passwords CHS-16 2 : BSD sum CHS-16 3 : SYSV sum CHS-32 1M (WRAP) : Olaf Barthel's CRC, Bootblock of OFS/FFS CHS-32 1I : CHS-32 2 : LightFileSystem EOR Byte : EOR Word (M/I) : EOR Long (M/I) : ByteKiller, RSI-Packer Sum Byte Signed : Sum Byte Unsigned : SQ Sum Word Si (M/I) : Sum Word Un (M/I) : Sum Long M : Root-, Bitmap-, File-, Datablock of OFS/FFS Sum Long I : MD4 : EDonkey, Samba MD5 : SHA1 : Normally the numbers are segadecimal (with the exception of CRC32-7, CHS16-2 and CHS16-3 which are decimal). GetCRC maybe used to calculate only one CRC and only print this one. This is done by passing a number as 3rd argument. Currently the long and word parts of Sum and EOR are not supported: CRC16-1, CRC16-2, CRC16-3, CRC16-4, CRC32-1, CRC32-2, CRC32-3, CRC32-4, CRC32-5, CRC32-6, CRC32-7 CHS16-1, CHS16-2, CHS16-3, CHS32-1M, CHS32-1I, CHS32-2, EOR-Byte, Sum-Byte, Sum-ByteU, MD4, MD5, SHA1 The result is the checksum printed to output with carriage return. This maybe used in scripts, with pipes and ... Use this tool as you want, but WITHOUT ANY WARRANTY! Contact me at: ********************************************************************* * snail-mail: * e-mail: * * Dirk Stoecker * stoecker@epost.de * * Geschwister-Scholl-Str. 10 * dirk@dstoecker.de * * 01877 Bischofswerda * world wide web: * * GERMANY * http://www.dstoecker.de/ * * phone: * pgp key: * * GERMANY +49 (0)3594/706666 * get from WWW pages or keyservers * ********************************************************************* Following is my PGP signature for the corresponding LhA-File. Use ' pgpv GetCRC.readme -o GetCRC.lha ' to check it. Key fingerprint: B9 F2 3A 1A 29 02 75 16 6A C6 5B 7D 5E F6 16 CF. All my releases after April 2001 have a PGP signature with this key. Be alarmed if signature is missing or wrong. -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 5.0i for non-commercial use MessageID: xpVg1/kW9E8rOFsJTqHiljkU5AM+IrZX iQCVAwUAPk+eQLOTsAT/iOY9AQGWFQP9HLGQ6e+d3eFPyBPE+EDZrWVjPDFeRUmo TrEb4FsBSdVp1o5YpUsgrrKTyprgNNorlDONMzggQkFYwXNeUkGVCFBPfNahbItc /HofKgrOHcNuWXf3P57Gf0VBgJtRNu4xutbN/bxkYTCUSRS4zd2fZF8F9bLQ6eOl dlHrkO9Tnfk= =GLTs -----END PGP SIGNATURE-----