So I created a patch that works around the copy-protection that is used in the Sega Genesis version of Puggsy. Since there isn't an entry for the game in our games list, and it's a bit of an overlooked gem, I decided to put in a short blurb about the game below.
Puggsy is a sidescrolling puzzle-platformer game with some neat physics elements developed by Traveller's Tales (yes, the same people behind Sonic 3D Blast, Mickey Mania, Crash: Wrath of Cortex and every LEGO related game since 2005) and published by the now defunct Psygnosis. It was released back in 1993 for the Sega Genesis/Mega Drive and Amiga, and later for the Sega/Mega-CD in 1994. The game sees you play as the titular Puggsy, an orange alien that vaguely resembles a space hopper toy, who got stranded on a planet foreign to him after the raccoon natives of the planet stole his spaceship.
With that introduction out of the way, all three versions of the game are virtually identical in gameplay, level design and general presentation. The only major differences between them are sound design and the Genesis version's rather clever copy-protection. As stated on the TCRF.net page on the game
, Traveller's Tales put in a rather simple yet ingenious anti-piracy measure that specifically targeted cartridge copiers from the time since they all used SRAM.
The copy-protection worked like this: the game tries to create SRAM and makes six different checks throughout the game to see if SRAM was created. If the game finds SRAM, it trips the anti-piracy measure displaying a message stating that you cannot play any further and that you should buy an actual copy of the game instead. Since the game strictly used passwords, and there wasn't a volatile RAM chip inside the retail carts of Puggsy, the copy-protection wouldn't have any means to trip under normal circumstances.
Despite the fact that Tt only intended this copy-protection to deter cartridge copiers that were around in the early to mid nineties, this method has proven itself to be future-proof as all flash cartridges and console emulators will blindly make SRAM data from any game that requests for it to be made. Even modern Sega emulators that aim to be hardware accurate like Kega Fusion, Genesis Plus GX, Exodus and BlastEm! are not safe since it cannot account for a piece of software requesting the usage of hardware it shouldn't have access to under normal circumstances.
Luckily, AndLabs, a member of RHDN, TCRF and Sonic-Retro had found the exact hex values of the Puggsy ROM where the SRAM checks are made and showed how to render them mute.
Despite the fact that he made this find five years ago, no one had bothered to make a patch out of this fix. Not until today, that is. Below are the links to patches for the US and EU versions of the ROM, in XDELTA format.
I want to again stress that AndLabs did all the heavy lifting to make this patch possible, and if it wasn't for him finding the hex values and posting them online I would not have been able to make and release these patches. The one thing I will make note of is that he believes that he found all of the hex values where SRAM checks are made, and as far as I could find looking into it myself I couldn't find any concrete evidence to the contrary. If you happen to find yourself getting the Tt sarcastic message of death please let me know. Anyways, enjoy!
UPDATE 16/9/17: So I found that both the US and EU versions of the game have the same three hexadecimal sequences for the anti-piracy checks. While the location of the last sequence differs between regions, the first two are located on the same addresses on both ROMs. I updated the EU version of the patch with the second address, with a new download link for it.