There’s been quite a lot of XaviX progress over the past month, including preliminary sound and a donation drive that allowed a whole bunch of e-kara cartridges to be acquired and dumped by both Sean and Team Europe.
The e-kara is an interesting little unit, with sequenced versions of songs contained in cartridges. It’s simple, and while there were only around 9 cartridges released in the US, and 7 in Europe (with a lot of repeated) it looks to have been a very popular system in Japan, with over 100 cartridges.
It also presents to us one of those interesting cases where world events caused a change in the software released for it. In most cases if a song appears in multiple cartridges it always uses the same background, however if you look at the US Starter cartridge, which is presumably the first US release, from the year 2000 you’ll see that Britney Spears “Stronger” contains a picture of the World Trade Center.
By the time Volume 8 had been released, in 2002, that image was clearly deemed unsuitable, as the background was changed. The same changed background is used in the UK/EU Volume 3, also from 2002.
Interestingly the ‘Germany’ Starter pack, which contains the same songs as the US starter pack, but is from 2002, chose to use a different image again, so clearly Takara took some time to choose what they deemed was a suitable replacement. What’s also interesting about this starter pack is it’s the only cartridge we’ve seen specifically with a ‘GER’ code, so there might be a UK/EU sampler out there too that isn’t yet dumped. It’s possible the only change there will be the image used if that sampler was released slightly earlier, otherwise there doesn’t seem to be any reason to have a specific region here (unless the content of one of the other songs was deemed inappropriate and censored, I’ll have to check)
Emulation of the e-kara cartridges, while still preliminary, proved very useful in pointing me at a bug in my XaviX emulation that was causing some other stuff to fail during boot, of note, Star Wars. It also allowed Lord of the Rings to start playing music without crashing / filling the screen with garbage. I noticed this bug because while most e-kara cartridges ran though the songs just fine, a single Japanese one was just crashing, despite the code being nearly identical. This highlighted an error in the way data was being fetched in certain cases.
The e-kara cartridges also told me a bit about the timer hardware the XaviX has, because the UK and US/Japan cartridges use different timing methods to accomplish the same thing. While my timing is currently entirely incorrect, this at least has given me something to go on when I look at correcting it.
Neither Lord of the Rings or Star Wars gets past the ‘Swing Sword’ / ‘Swing Lightsaber’ screen, because those input devices aren’t yet mapped (it’s some kind of sensor array detecting the shiny surface of the controller to get a 3d space position and orientation, I not only need to get my head around how the game is reading the inputs, but how I’m going to map any conventional device to give it a signal that might make it somewhat usable on a PC)
Dirt Rebel MX also saw big improvements due to Lord of the Rings pointing me in the direction of some bugs with the new Super XaviX opcodes I’d implemented, with the road now being correctly rendered. It also told me that there were errors with the implementation of the math unit, which I then fixed. This also required raster interrupts, which I’d implemented for Snowboarder. The game is basically playable apart from the EEPROM saves not working correctly, looking at those is slowly becoming a top priority.
I also spent some time looking at the background tilemap on Monster Truck, it uses an ‘indirect’ mode that so far nothing else does, where tile attributes (colour / flip) are stored right before the graphic data. I think I’ve got it figured out now, as all backgrounds render correctly. I also added preliminary analog steering controls (implementation needs to be improved still)
After trying to work out x-coordinate handling for a while, I settled on a kludge that seems to work in all cases, meaning sprites wrap more correctly on many games, which is very noticeable in-game on Snowboarder, with the playfield looking more correct. The Nostalgia packs also benefited significantly from this.
Play TV Rescue Heroes now boots too. This one was aimed at kids, so not much of a game. Strangely it’s the only XaviX product I’ve seen that fails to display either the XaviX logo or an SSD copyright anywhere; this might have been an oversight on the part of the developer as it looks very much like it was a license requirement. Some of the controls still need mapping. This also needed some sprite mode fixes as it uses a sprite mode nothing else does.
Some addressing fixes when executing code from upper banks, and a cheap semi-random implementation of the ball controller allow both Football and Madden Football to get ingame without crashing, although without a more accurate emulation of the ball they’re not especially playable.
Wild Adventure Mini-Golf can now be convinced to go ingame, although still lacks proper controls, so all shots have no power.
Some tile addressing fixes solved a video problem in Ping Pong aka Table Tennis. Again no controls yet, but it’s closer to having them than it was.
The raster effects, math fixes and Super XaviX opcode fixes also helped with XaviXport Tennis. This is also the only game to be using some kind of Super XaviX bitmap mode, it uses it for the title screen and for some reason the bitmap is larger than the display. Either the game is meant to be in a higher resolution mode at this point, or it’s meant to scale down the bitmap, I need to figure out which. I know it’s in an Interlace mode, which would explain the vertical resolution, I probably have to skip lines, but the horizontal resolution difference is a mystery right now. Like the others, no controls yet, but the improvement in attract mode is significant, with the math fixes meaning the demo now plays properly.
Dragon Quest now boots to what seems to be a calibration screen due to the same fixes as Lord of the Rings and Star Wars
That just about covers improvements to the various XaviX based games, things like Card Night and Bass Fishing are pretty much how they were before (although the addressing bug that I fixed for e-kara etc. means Bass Fishing is now more stable and both have music that seems to play at 100x the expected speed) I’ll talk a little more about some e-kara stuff now.
While all of the regular Japanese e-kara carts (EC series, GC series) have the same basic presentation as the US / UK ones (see shots)..
..there were also some different cartridges for Japan (for example the MC and SC series) These had increasingly fancy menus, showing the full cartridge titles and custom menu presentation. There were also several other series of cartridges, some even designed for different hardware, or multiple types of hardware, but we don’t have any dumps of those.
That brings us on to some less positive news. While we can potentially dump and document all the released e-kara cartridges, and those for similar systems, assuming we can get hold of them there are some things that have likely already been lost to time. It seems that between 2003 and 2009 Takara sold an e-kara WEB unit. We picked up one of these and it’s a device, with an e-kara cartridge that connects to a PC. On the PC you downloaded (or it was supplied with, but we don’t have) a piece of software that connects to a web service in order to download songs and transfer them onto the e-kara WEB cartridge. Presumably copying them to Flash ROM as there doesn’t appear to be a battery. It looks like many hundreds of songs were released this way, but it also looks very much like the service no longer exists, so no songs can be downloaded.
The cartridge we picked up is apparently empty, most of the ROM is blank, and it shows no songs on either an e-kara unit, or under emulation.
Now, assuming it is a flash mechanism, it’s possible there are cartridges out there where people have downloaded songs onto them, which could be dumped to preserve that data, but unless somebody knows what they have we can’t just start buying up random e-kara Web cartridges in the hope that they contain something. The sheer number of songs, and limited capacity of the cartridges also surely means some things are going to be lost even in the best case of people donating old cartridges to us. I could be wrong about the service no longer being available, but the website listed on the title screen no longer resolves, and I can’t find any software to attempt to connect.
The Internet Archive has various snapshots of the Takara sites right up to 2009, including the e-kara Web one, but there appear to be no downloads, presumably because you had to download through the software.
Sean even kindly scanned the e-kara Web manual, but it doesn’t seem to contain anything to help us here.
e-kara WEB manual 1
e-kara WEB manual 2
e-kara WEB manual 3
e-kara WEB manual 4
e-kara WEB manual 5
e-kara WEB manual 6
e-kara WEB manual 7
e-kara WEB manual 8
So it’s most likely we’re going to have to accept that a lot of content for this system has been lost, because it was download only, and that’s only going to become a bigger problem in the future with so many products switching to that model; it’s one of the biggest dangers to keeping our digital history alive, things are lost with the flip of a switch that could happen at any moment.
On a more positive note, we did pick up a few other XaviX things, and they’ve turned out to be easy enough looking cases for Sean (they have pads near the ROM to solder onto for dumping) so hopefully he’ll find time to dump them and we’ll have a little more evidence contributing to improving the emulation, so far everything that’s been dumped has helped tell us something about the platform.
— some videos of recent progress related to the article
https://www.youtube.com/watch?v=hSbDMOa7N7s Monster Truck
https://www.youtube.com/watch?v=3JulMHjbpIQ Namco Nostalgia 1
https://www.youtube.com/watch?v=Aj8Fyxmbbko e-kara (cartridge ‘SC0005-SAI’)
https://www.youtube.com/watch?v=rA_eWOeL9QE XaviX Tennis
https://www.youtube.com/watch?v=5jmR1fPWLao Dirt Rebel MX
https://www.youtube.com/watch?v=X43j8QJJR2U Lord of the Rings
https://www.youtube.com/watch?v=VMAf1H8uoZ4 Star Wars