What is it?
It's a program which reads in the headers found in SMS and GG roms, and does its best to interpret them. It can read the Sega, SDSC and Codemasters headers, and it checks the various checksums too.
Header Reader (191KB)
Includes Delphi 7 source and a lot of information on Sega rom headers.
Quite out of date.
Updated for all checksum ranges and header locations allowed by the US SMS BIOS, and source tidied up a bit more.
Updated for checksum range 1 (Chuck Rock 2), also cleaned the source a bit
Updated for SDSC tag 1.01