Fantastic Dizzy (Master System) crashing on real hardware (Mega Drive + Everdrive)

Hi,

I own two Mega Drives model 1 (PAL and NTSC-J) and an Everdrive, which allows playing Master System ROMs. This works perfectly fine for the most part, but there's one game that gives me a headache - Fantastic Dizzy. The SMS version seems to be badly programmed in general as it often crashes in emulators as well (sometimes even killing the whole emu). However, I can't get it to work on the console at all. I'm not sure if there's a problem with this game, or with the hardware I'm using, or both.

Basically, after the Codemasters intro screen, the graphics are displayed incorrectly, ie. the sprites are shifted down way lower than they're supposed to. The title screen crashes after few seconds (the sprites disappear altogether, and that's it), but if I skip it I can get to the gameplay, but it doesn't help much - the sprites are shifted down here as well, and the game either crashes instantenously or after a short while of playing.

There doesn't seem to be a big difference when running this game on a NTSC-J or PAL machine; maybe on PAL it crashes a little bit later, but it's uplayable either way. I've tried changing Everdrive settings (SMS BIOSes, etc.), to no avail.

Any ideas? Is the Everdrive to blame? Does this game run only on a real Master System? Or it's just a piece of crap? (that's most likely :tongue: )

I've only played the game on emulator, but in multiple playthroughs I don't recall it crashing. Are you using the original cartridge or just ROM dumps? If it's crashing on everything you have, I would think it's either a bad dump or really picky about having authentic Master System timing. If on cartridge, maybe the connectors are coming loose at some point...?

I know that the game can easily crash in emulator while using fastforward/speedup, it sometimes hangs for me (after starting the gameplay) when alt-tabbing outside emulator, opening menus in emulator window or just at pure random - I don't know what that's about. I played the game on Fusion emu on PC, and on Picodrive on PSP, with similar results. A few times the whole emu crashed and I had to reboot the PSP - I don't know what that's about.

Anyway - I don't own the original cartridge (nor a Power Base Converter required to play SMS carts on Mega Drive), I run the game from a flashcart, and the ROM comes from a No-Intro collection. I've tried a ROM from another source, but with the same result.

To be honest, as much as I like Fantastic Dizzy I don't really think this version is worth the effort, but still - it'd be nice to beat on the real hardware. In all fairness though, maybe I shouldn't have called this game "badly programmed" just because it crashes in scenarios it wasn't designed for. With that said, it's one of the very few examples of a game (or even the only I can recall) that crashes when using fastforward, which is something I can't wrap my head around. I don't know if my problems running this game on console from a flashcart and emulation issues are in any way related.

//edit: just out of pure curiousity I've downloaded two emus that claim a very high degree of accuracy, Regen and blastem. In Regen, the game seems to crash frequently when opening any of the menus in emulator window (I suppose it's because the emulation pauses for a brief moment and the game doesn't recover from that, for whatever reason), and using fastforward/turbo is an instant crash. In blastem however... the game doesn't work at all. Form what I've found Codemasters SMS games use a non-standard mapper which is causing issues. https://www.retrodev.com/blastem/trac/ticket/28


//edit 2: Retroarch seems to handle this game just fine, no crashes whatsoever. Could be because this emu is presumably the most maintained as of late.

Ah, you're right, my old copy of Fusion did produce some glitches when I tried Fantastic Dizzy in it again. Lately I've been playing Sega Master System games in BizHawk, with the... SMSHawk core, it says. I played all the way through Fantastic Dizzy on it without issue, and it seems to have no problem with fast-forward, either. You have to supply your own BIOS, though, and I don't know if that ever affects it. And this latest version of BizHawk I downloaded likes to play the sound too high on everything until I make an arbitrary sound setting change...

The one glitch I remembered doing on emulators for a long time was loading the Game Gear ROM in Master System mode (or was it the other way around?), which made it run with all-black sprites on a dark blue background. I guess that's the difference in color palettes between the two systems!

After some more digging, it seems like the custom mapper from Codemasters games is indeed the culprit. These games seem to have emulation issues in general (in some emulators), and some people report that even the real cartridges don't work on all console revisions! I've read conflicting info whether MD1 should be able to run these games. Apparently Codemasters developed their games without a licence and any support from Sega and have basically reverse engineered the console by themselves, and they've ended up using a screen mode that isn't supported by all hardware versions. Neat. Since the MD lacks support for the SG1000 video mode, I'd hazard a guess that the "Codemasters" screen mode support isn't there either. (not that these two are in any way related, but it shows that some SMS features were omitted in the MD)

I've checked a few other Codemasters SMS games on my console, and their compatibility seem to be hit and miss:
- Micro Machines: sprites are shifted lower than they should be; main menu background is cut off from the top and bottom; the image flickers and glitches when scrolling.
- Cosmic Spacehead: sprites are shifted lower than they should be; scrolling the screen on point-n-click sections leaves a garbled mess; the background in platforming sections is completely glitched.
- Dinobasher: this one seems to work almost fine. I remember though that this game can sometimes stay on black screen when falling down pits with hidden "bonus" levels - this could be because the game was unreleased, thus presumably unfinished. Maybe it would happen on emulators too.

At this point, it seems like running affected games on a Mega Drive is highly unlikely (even from a real cart via Power Base Converter), without patching the ROMs at least. What a bummer. Oh well - not a huge loss, NES versions of these games are better anyway, I've just wanted to try them out of pure curiousity on console. They're not worth spending the money on a Master System I reckon.