David Haywood’s MAME(tm) WIP

This was labeled as ‘Unknown Sidam Blister’ it appears to be a unique 8080bw based Asteroids clone called ‘Astropal’

Doesn’t quite work yet, inputs need mapping. I’ve asked stephh if he wants to look at it. Nice find anyway :-)

For a long time two CPS2 sets, the CPS2 versions of MegaMan and RockMan, have been left without a decryption key and thus been non-functional. The CPS1 versions have been supported for many years, but finding the keys for the CPS2 versions was proving to be very difficult as the CPS2 and CPS1 sets were not identical underneath the encryption due to hardware differences between the platforms.

It had been assumed that the two versions were simply too different, to the point of giving up with the usual line of key finding attacks Nicola has used to find the keys for the other sets. However, after studying the sets myself I realised that a large amount of the code probably WAS the same, just offset in the rom. Many code functions were surrounded by similar data, and were of the same size in both versions. By assuming that these functions were the same, and realigning the code we ended up with a much closer match between the CPS1 and CPS2 sets, allowing the standard attack Nicola devised to work.

As a result, keys have now been found for the CPS2 versions of the game. This means every currently supported CPS2 set has been decrypted. The Megaman CPS2 set is actually a limited release ‘SAMPLE’ version, as the game was (to my knowledge) never fully released in the US. The main differences in the CPS2 versions are the use of Qsound hardware for the sound, and an Eeprom to save game settings (as opposed to dipswitches).

MegaMan

RockMan

As a bonus (thanks to Chris Hardy) 2 new Euro parent sets are now supported and decrypted too.

Dimahoo (Euro)

Street Fighter Alpha 3 (Euro)