Plutiedev's blog


Stop being obsessed with "authenticity"

Published on 2019-oct-03

Rant time.

Something that annoys me is how people seem obsessed with looking "authentic" and how they think you absolutely need to provide unique box designs for every region (and of course both "old" and "new" designs for each, since the designs changed halfway through the console's lifetime). Does anybody realize how much of an inventory hell is this?

Worse yet, there's the trademark infringement issue — they just look too close to the official Sega designs, and Sega definitely has trademark on those again nowadays (both because of Sonic Mania and because of the Minis, not to mention all the Mega Drive merchandise). No, using "16 BIT CARTRIDGE" doesn't change the fact the design is still too close, if anything it only makes it look like a cheap bootleg.

Also, it's not like we're selling these games at local stores that you walked in and looked at the shelf for a game to rent or buy, but rather at on-line stores that sell globally, if not outright a Kickstarter campaign. That also kills the "authenticity" aspect really hard. On top of that, our new games look nothing like the ones from back in the day, as our culture has changed a lot since then.

Can we just admit that this isn't the '90s and acknowledge we're doing a whole new thing?

So what then?

I'd honestly prefer if we just dropped the Sega-like designs and let the game artwork fill the whole box. When we aren't pretending to be a Sega knock-off the boxes will look a lot better and feel less "bootleg", and you avoid risking the anger of a lawyer who may be in bad mood that day. Also, it means you just need a single box design and won't need to worry if you sell too much or too little of a given edition.

Acknowledging that we're a global market (if niche) also means no region lockout. Thankfully I haven't really seen trouble over this yet, but it means you should always consider "universal" shells when possible (those that fit in both Western and Japanese consoles). This way nobody has to worry about whether a game will work in their console or not, and again the inventory benefit of not having to worry about multiple editions.

Also don't forget to check out commercial homebrew guidelines in this site! There's some useful advice there, coming mostly from previous experiences. Learn from our past mistakes and you'll make everybody's lives easier.

Arkagis Revolution's weird revision scheme

Published on 2019-sep-10

The two Arkagis Revolution trial versions so far are revisions XZ and YX. If you paid attention, at Joypad the title screen said revision XY and at Gamescom it said XW. What's going on with these revision names?

It has in part to do with the Mega Drive ROM header format. The serial number field has a revision number going from 00 to 99. The problem is that this field is intended for released versions (00 being the first release), and these trial versions are pre-release (something Sega had never accounted for). I could have just started counting from there, but then the first proper release wouldn't be 00, which doesn't feel right.

Instead of doing that, I improvised a pre-release versioning scheme, using the letters X, Y, Z and W. This gives me up to 16 pre-release revisions (XX, XY, XZ, XW, YX, YY, YZ, YW, ZX, ZY, ZZ, ZW, WX, WY, WZ, WW). Feel free to copy it, I hope we never need to go beyond that! When the game finally launches for real, I'll switch back to the normal revision scheme (00, 01, 02, etc.).

You may also have noticed that I didn't mention which revision was XX. That was a privately distributed revision, and as such you're not going to have seen it in any form.

Dumping games in the early '90s

Published on 2019-feb-14

(more like mid-early '90s)

Story time: some years ago, I downloaded a Mayhem in Monsterland dump. Whoever uploaded it clearly had just done LOAD "*",8,1 and called it a day because it wasn't even remotely a good dump (nor even just a crack dump): a quick look at the directory showed there was another game inside as well as a letter. The letter is what I want to talk about.

Here are the relevant parts of it (to screen readers users: I've transcribed the relevant part below)

Transcribing the part I want to talk about because the font is awful:

deadbone/breeze design: Yo bevan! I hope that you've still got your 64 left so that you can read this! hehe… OK, many thank for your send… Yes, you read right on the boot-text but I don't have a SNES, at least not yet… I wrote it there because that I've got some friends that have got wildcards and also because that Trasher will buy one soon. We're also able to get the latest SNES games as Surfer (the leader of Active) works as a game-reviewer for one of the absolute biggest newspapers in Sweden.

Therefore he gets all the new games for SNES/Sega (and more systems) directly from the importer to review them, and I don't think you have to guess long to understand that he of course makes backup copies of it all to himself!! He already supplied some Sega first-releases to Censor and Auartex! I'm thinking of buying a 24M wildcard & SNES myself as you see that I can get all the new games for it, but we'll see… I'm not such a big arcade freak, and most console games are in that range, so… But it would be cool anyway! I've heard rumors that backup systems for consoles will get illegal here in Sweden in the beginning of 94 so I have to think fast if I want one while it's legal to buy…

I saw some demo names on the list of your SNES stuff. I've never seen any console demos so could you please send some over, but wait until I've spent some HD disks over to you of course! I'll copy some SNES stuff for you as fast I can… but as I've got quite limited spare time it could take a while.

As you can see, Censor and Auartex (is that meant to be Avartex? going by the letter's spelling…) would get dumps of Mega Drive and SNES games directly from a game reviewer. Seeing as some Censor releases have been found to be prototypes, I thought I may as well bring this up.

For those curious (hello demoscene fellas!), here's the full letter: screenshot dump of letter

Off-line modes in modem software

Published on 2019-jan-19

A bunch of the Mega Modem stuff is designed around some on-line service that of course is long gone by now. But some of them actually feature some form of off-line mode as unlikely as it sounds.

1200bps modem noises

Mega Anser

Mega Anser was a piece of home banking software. Of course, the service is not available anymore, but what many people don't know is that it still works without the modem (in part because it's one of the few things that doesn't work without a standard controller, it needs the Ten Key Pad).

Screenshot of Mega Anser showing the bill for a payment in simulation mode. The transfer is 15,000 yen and the tax is 206 yen. Because you get taxed even during a simulation.

If you try to use Mega Anser without a modem connected, it'll go into "practice mode" (練習用). In practice mode, Mega Anser will give you a few bank accounts with 1,000,000 yen each and you can do everything you would normally do with a real bank. You can also set up the password, change the modem settings, etc. Occasionally it'll even pretend that there was a connection error.

Sansan

Sansan, SanSan, San San, whatever. サンサン

This game was used to connect to the Sansan service to let you play Go with other people on-line. Of course, the service is gone now, so people assume that it's unplayable anymore. What most people don't know is that it has a local multiplayer mode! (or something that can be used like one — no AI players, sorry).

Screenshot of Sansan's local multiplayer mode. The pieces spell "puru puru", because Sik doesn't know how to play Go.

Sansan will refuse to go anywhere without having initialized memory, so if this is the first time you're playing it you need to do this:

Once memory is working you can access local multiplayer as follows:

Note that both players share the same controller (taking turns, of course).

Old Mega Drive things

Published on 2019-jan-17

I was reading a thread about SNES gurus on the NesDev forum and seeing people discuss about old timers got me thinking about how I've been around for much longer than it seems and how I seem to remember some stuff a lot of people have forgotten (granted, my memory is flaky so I also tend to screw up a lot).

Tripping into legacy cruft

You may be aware of the ROM padding article in this site, there's a reason behind it.

Some time ago last year I was talking to Drag00n (the Second Dimension guy) and he casually mentions that somebody reported some edge case bug with the SWITCH instruction that seemed to show up or go away depending on the surrounding code. Being the distraction machine I am, I end up interrupting whatever he was doing in order to figure out what was going on. Whatever.

Anyway, I convince him to load the ROM (expecting this to be a pain to figure out), and he says that Fusion just showed a blank screen and that the titlebar was garbled… and wait a minute, but the ROM header is right? And it was ASCII, so not an encoding issue. The game can't set the titlebar (Fusion takes it directly from the ROM header), so garbled text means that Fusion for some reason didn't load the ROM properly.

And then it hit me: Fusion ignores the file extension and tries to autodetect instead. If the ROM is not padded and the stars align just right, Fusion will misdetect it for being in SMD format (Super Magic Drive dump), which is split into blocks and interleaved and of course will result in a completely wrong ROM. This isn't unique to Fusion, I recall some flashcart loader having the same issue long ago. The easiest way to work around this is, of course, padding the ROM to a reasonable size.

I bet some of you are confused now: new people to the scene probably don't even know what SMD is, and older people will wonder why the heck would anybody use SMD these days. Thing is, Fusion had been around for long enough that SMD dumps were still relevant when it first came out, hence why those files are supported. Newer emulators indeed don't bother with it usually, but many people still use Fusion, so this issue still pops up every so often.

I only spotted this quickly because I had met this issue many years ago, otherwise it'd have been probably dismissed as something impossible to debug and just give up because any change would make it go away.

6MB ROM limit in Fusion

A much less known thing is that Fusion supports ROMs up to 6MB in size… from what I recall when talking with Steve Snake at least. He mentioned that for some reason emulators were supporting 6MB, but he had forgotten why. This was in the context of me using the Sega mapper to make a Sonic 3D hack larger than 4MB (since the ROM barely had any space left).

The only released game using the mapper was Super Street Fighter II, and that one is 5MB (and indeed, that's the maximum Regen supports). What's going on?

I'm going to take a wild guess here, but I think the issue may have been Sonic & Knuckles. See, the lock-on mechanism wasn't properly documented until recently, and while it's emulated nowadays, back then the common way to do lock-on was to literally append the locked-on ROM to Sonic & Knuckles. If you tried to do this with the largest games, the resulting file would be 6MB. Some emulators statically allocate the memory upfront and may blindly load the entire file as-is, so by making the limit 6MB they could ensure the merged ROMs worked (even if 2MB went ignored).

Other stuff

Part of the reason why I made this site is because there's some obscure stuff I know (like how the Mega Anser accessories work) that I don't want to get lost. Which is probably also why so far articles have been leaning towards the obscure stuff instead of the more basic things like sprites or scrolling (I really need to get more serious about that…).

Another example of stuff mostly forgotten is a few test ROMs from SOA's hardware R&D department (in large part because they aren't in no-intro…). A couple of them are for testing the Activator (and turns out there was an Activator command that had gone undocumented until not long ago), there's also a ROM for testing a "head mounted display" which presumably is the only trace left of the Sega VR (I can confirm there's something there, I need to finish looking into it), eventually I'll try to document both of those in this site. Game Toshokan has support for yet another peripheral in the modem port, albeit it's dummied out in the released version (as Game Toshokan shows an error message if there isn't a modem there, otherwise the code seems intact). Also buried in the Sega documentation is a mention of a "RAM disk", although sadly the only thing we have left from it is its peripheral ID (14 aka %1110).

There's probably more stuff to talk about, I'll try to get around it when I get time. A lot of stuff only comes back again after something unrelated happens to bring back the topic. You never know what may show up next!