The last very awaited MAME was MAME v0.31. Why? Simply becausethere were no public betas before that. Why was this one of the greatestreleases ever? A huge surprise came in the form of the Atari System 1 games.Nobody expected to play Marble Madness, Toobin, etc because there wasthis dreaded Slapstic chip that encrypted everything. Enter Frank Palazzolo,chip bounty hunter. With a mission set, and with Aaron Giles, as his partnerhe uncovered the workings of this mysterious chip and granted you the giftof playing those great games. With this as a topic, we directed our attentionto Mr. Palazzolo to exchange a few questions about "The Dead of Slapstic".
|The Dead of Slapstic - September 12,1998 by JoseQ
1. Back to tradition, can you tell us a little bit about yourself, andwhat motivated you to get into emulation?
Well, I'm an Electrical Engineer working as a Programmer/Manager. I first heard aboutgame emulators in early 1997, thanks to the Emulation Repository WebSite. I've always loved the old games, and in some ways theyaffected my career aspirations as a kid. (I always wondered what was inside thosemagical machines.) I worked in an Arcade in high-school, never thinking that thesegames would be all but gone someday. Today, being able to breathe life into thisold technology is a lot of fun, a technical challenge, and it brings back a lot ofold memories.
2. What keeps you working hard on it? Does it seem as exciting as ever?
Yes, actually it does. This hobby is fun for me on all levels. There are thetechnical challenges, both in understanding the hardware and software, like theslapstic. Then, there are the preservationist and nostalgic aspects. I like to collect thesegames, but I realize that many of them will be all but gone if people weren't doingthis kind of thing. I'm glad my grand-kids are going to be able to see what thesegames were like 50 years from now. For me, it's like having dozens of irresistablepuzzles to work on, AND having a great motivation to work on them.
3. What are your current projects (drivers?), and aspirations?
I like to work on audio, older games, and games with unusual hardware.I tend to jump around a lot! :) I'm looking at a lot of audio-related stuff at the moment:Emulated speech in the Sega Vector games, analog sound circuit simulation, sound inGorf and the Astrocade Games, other security chips, etc. I'd also liketo work on some kind of simulation for the pre-CPU games, (There are a lot of them),in MAME, and add some obscure consoles to MESS. I just wish it was myfull-time job.
4. What initially motivated you to put the Slapstic into the "goal"box? Was it a particular game?
Well, it was curiousity for me, initially. I started off just investigating a little bitwith Empire Strikes Back, then got distracted. Later, Aaron Giles proposedthat he'd write the Atari System 1 drivers while I worked on the slapstic chips thatwent into those games. At the time, this was a great division of labor because Icould really concentrate on the hardware.
5. Were there any previous (hardware/software) attempts to beat theslapstic?
Yes. Cliff Koch actually made a "replacement chip" for collectors who wanted toconvert their Star Wars into an Empire Strikes Back. This acted pretty muchlike the slapstic chip used in ESB. Also, The Gauntlet I and II slapstics had beenfigured out enough to create the hacked ROMs for Gauntlet and Gauntlet II. Thisalleviated the need for those slapstics for collectors, and allowed MAME andNeill Cortlett's Gauntlet emulator to work for those games. Finally, I think therewas another unreleased emulator out there that had made progress onESB.I think most people were concentrating more on "how to beat it" ratherthan on "how they work". Subtle difference, but because MAME is meant asdocumentation, and we had multiple games to worry about, that's the approachwe took.
6. Had anyone in MAMEDEV attempted to break the slapstic, or emulateother games that were poised by this in some form or another?
Not really. There was some work done on ESB by Steve Baines, andAaron started on the System 1 stuff before I got involved, butthat was about it.
7. From what had been told, this dreaded chip was a major wall toemulator authors. What approach did you use to solve the puzzle?
It was a team approach. Aaron worked on the driver software, alongwith reverse-engineering the game code whenever necessary. I built upa special fixture for interrogating the chips, and wrote some code todo that with a 68HC11 board. Between the two of us, and a steadysupply of chips from others, it all came together. And now that it's in the MAMEcode, the info is available to any other emulators that want to use it.
8. So the 68HC11, I've had my share of experience programming witha development board with this microcontroller in it, and I can sayit's excellent. For our readers, can you tell us what it is, whatit can do and how can someone go about getting one?
Well, it's basically a single-board computer. It's CPU is a Motorola68HC11 chip, which you can program in assembly or C. Among otherfeatures, It has a serial port to connect to PC or Mac, and a bunch of pinsyou can control via software. If you write up the appropriate software forit, and build an adapter for the item you're testing, it can be very powerful.I've used it to read non-standard ROMS, slapstic cracking, etc.I got my original one long ago as a "leftover" from a school project.I recently bought another from Motorola, when they were running apromotional special through one of their a distributors. It shouldbe on their web site.
9. How did you get your hands on those Slapstic chips? Are Slapsticsdifferent each one from the other, or are they basically the samechip in all the games?
Several collectors on the MAME team sent me chips. Aaron even deliveredone in person, while on vacation. Are they all different? - good question.We didn't know the answer to this one at first. We newthat some games use the same exact chips, and we also new somecouldn't be interchanged. We eventually determined that they all dobasically the same thing...but they use different addresses as "keys"depending on the part number. Guessing, or scanning the chips is theonly way to get the keys.
10. How long since the development started until you got the firstslapstic game to work? How were the attempts? Did the game driversworked preliminary or was it an all or nothing deal?
I think it was a few months, give or take. Some of the drivers workedpreliminarily without any slapstic emulation, but they'd mess up sooner or later.As it turns out, the Gauntlet games only access the more advanced featuresof the chip on later levels, so they started to work right away. I rememberI thought we were done a little too early :)
11. What was the first game that made it through?
Well, even though the Gauntlet's were working ok, we knew that the othergames used "the rest" of the slapstic functionality right away, because theywere basically broken. I had been querying the Marble Madness slapstic, and thelatest code I sent to Aaron still wasn't working. Then, Aaron noticed a codesegment in the Marble Madness game code which hinted that maybe he shouldtry to tweak the slapstic code a bit (a one-line change). Marble Madnessworked flawlessly! Based on that, we knew how they all worked.
12. You must feel very proud to have "The cracking on the slapstic"on your back. What do you think were the major factors that helpedthis come true?
Well, working with the MAME team is excellent. The team has peopleof many different talents. It would have taken me forever to do whatAaron did, for example. And without the chips I couldn't have done anything.We had the software talent, hardware talent, and parts, and the emulatorframework.
13. Are there still things about the slapstic that remain uncovered?
Well, a bit. We've still got the bugs in the Gauntlet games to be fixed,and of course there's still the Empire Strikes Back, and some others.But, I believe it's only a matter of getting the right keys, not of understanding.
14. What is your next Mt. Everest? Is there something now as dreadedas the Slapstic was?
Nothing really stands out at the moment. A lot of the current "security-chip"and "encryption" challenges revolve around more modern games, which don'thold quite the same charm for me. (although I'm sure I'll end up involved if I can help.)Seems like you never know when the next Everest will show up, though.At least I usually don't dread it when it does :)
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