The Arcade Hacker blog posts some fantastic news on reverse engineering the security in the Sega System 16 / 18 / 24 / X.

Dear all, after some lengthy testing we are happy to release full details on the security programing of the Hitachi FD1089 / FD1094 cpus used in Sega’s System 16 / 18 / 24 / X motherboards.

This guide is the result of several years of work by a small group of arcade enthusiasts to unravel the secrets of the security implementation found in one of the most loved and popular arcade game platforms. Thanks to this work it is now possible to fully preserve most Sega 16 bit systems enabled with security as fully working unmodified originals.

The work involves an Arduino Mega with a large shield to tie the pins to the Hitachi chip.

Having inserted the module in the socket we can proceed to program the security keys by typing w and pressing enter. Make sure you replace the module battery if necessary before attempting a key load, a new battery will last at least 20-30 years so don’t expect to have to repeat this often. Once the process finishes you can disconnect the Arduino module from your computer and remove the cpu module.

Read more