Saturn rings

After some initial issues Rhea has been upgraded to V1.5 and works pretty stable now. As in boots everything I throw at it. Which brings me to subject at hand: Many of the existing images of Saturn CD-ROMs are pretty poor.

I’m going to have to put a line somewhere because I don’t want users to complain about the device not working properly when the problem is with the dump itself. Only certain formats will be supported, and as always I urge you to make your own dumps. It’s not that complicated, Saturn discs can be read on a normal PC drive – no special hardware needed.

Supported formats:

CDI – Preferred. Needs to be either RAW or (optional) RAW+SUB format. CDIs include pregaps (index 0 parts of the tracks) by default which is good.

MDS/MDF – I’ve just added preliminary support for this format. The only few images I have are in RAW+SUB format, but just RAW should be fine as well.

BIN – Only for single track images, needs RAW sectors. Since I haven’t seen a single track game yet I don’t think this one will be of much use – perhaps for homebrew.

I’m looking at CCD/IMG format now, I might add some limited support for that as well since it’s popular. Please note that having the dump in supported format doesn’t yet mean it will definitelly work – the file format is one thing, and the quality of what’s actually inside is another.

Not supported:

CUE – Anything that depends on CUE will not work. I’m not even talking about ISO+MP3 tracks, which are the worst, but the whole format in general. There are many ad-hoc extensions to the so-called standard CUE, and the tracks can be multiple files, single file, RAW or MODE1, even compressed via MP3 or FLAC, or converted to WAVE instead of raw audio data. Single file “pregaps” are just zero-filled space even for data tracks. And to add insult to injury the MSF address of each track is always +2 seconds, pregap or not, because it was more funny this way.

Some CUE based dumps can be converted to a more sane format and will work. I’ve tested it by mounting the image in Daemon Tools Lite and re-ripping it with DiscJuggler to CDI.  For some reason DJ doesn’t see WinCDEmu virtual drives, so that’s why DT. That’s just one possible option, and obviously if the dump was bad to begin with this will not produce a working image. But might be worth a try if your disc is damaged and unreadable and CUE is all you’ve got.

It’s always best to stick to properly made dumps, even if these need to be converted you know the data is good. I can’t guarantee correct operation otherwise.

Last thing – turns out the 21-pin Saturn drives come in at least 3 versions, with some rather important differences between them. While the idea is to be able to support all models, so far Rhea can only emulate 20-pin drives. That raises 2 questions:

Would any of you be interested in buying an earlier, 20-pin only model, or do you want to wait for a more final version. This will still take weeks at best mind you, assuming I can make a universal emulator at all.

There’s going to be some soldering involved – at least to connect 5V power supply (so 2 wires) since every drive has a different connector for that and it’s not economical to add all of these. Not to mention you’d be limited by the length of original wires. With the differences between 20- and 21-pin drives I will also need some form of easy configuration (auto-detection not really feasible), I was thinking solder pads that can be connected (or left open) via a small solder ball. Easy, but somewhat permanent. Proper jumpers are another option but this needs more space, PCB height, and I think would only be useful for people who have just 1 Rhea but several different Saturns. A hindrace and potential source of problems if the jumpers loose good contact due to age for everyone else.

What do you think?

66 thoughts on “Saturn rings

  1. I’m interested in buying a prototype, I have two Sega Starun 20 PIn and a lot of BIN+CUE images I’d want to convert and try.

  2. I say make an early 20 pin version. You will no doubt get takers for it. Is there an easy way to determine which drive the unit it has (20 or 21 pin) from markings/numbers/letters on the external casing, or is it necessary to open the saturn up?

    • Opening is the best option, as I’ve learned the so-called model 1 Saturns (with oval buttons and CD access LED) also came with 21-pin drives. Also, the case or internals might have been replaced so it’s best to check.

      • Stupid question: what am I looking for exactly? I opened up m Saturn, but I’m still not sure how to determine which model my drive is… My system is a NA launch model; MK-80000 Serial No. B5 001858

      • Count the “wires” in the flat cable (FCC) connecting the drive and motherboard. You should be able to do it without having to disconnect it.

  3. Would like to see a more flexible application. Even if there is soldering involved. Either way I am a buyer.

  4. Do you think it is possibel to use “DD” under linux to produce a proper image?
    For sure once your board is ready I’ll purchase one ^_^

    Offtopic: there is another machine that would greatly benefit yoru skills: the Gamecube.

    • dd won’t be enough I’m afraid. Even if it could dump the disc as one stream of RAW sectors, for both audio and data, there would be no TOC information to go with it.

      • On linux, mount the disc with gCDEmu and dump it using DiscJuggler. DJ works very well via wine.

  5. Not supporting bin/cue will possibly piss off a great many people – it took over a decade to re-rip everything from iso/mp3 into proper RAW bin/cue. I can understand the reasoning (did a lot of tests on the format myself, the number of variations are really quite silly). Support for at least single 2352 mode bin + cuesheet would be nice. All those iso+wav+wav etc rips could be disregarded….

    CloneCD is also important, as the highest quality rips (trurip) as of now are in CloneCD format (ccd/img/sub).

    Speaking of subcodes, I’m assuming you generate those? If present, can they be used from the image itself? It would only help with the one or two CD+G discs that exist, so they’d be a cute little extra detail.

    The real knockout would be support for the format used by the developer tools CD emulator system, dsk/rti (similar to clonecd/bin raw images, but includes 98 byte subs+two sync bytes directly after an audio sector). Nah, just kidding.

    • Proper CUE dumps with RAW tracks can be converted and will work. Direct support is unlikely though. Also, these omit subs anyway🙂

      I spoof subs now, I could add proper support for images that have it but other than my own CDIs it’s just CCD, and currently my code is not capable of reading subs from a separate file. Could be added though. What games use +G?

      As for low-level dump, as long as it’s not pure EFM stream it won’t be able to cover all tricks in the book. But pure EFM would require a lot more CPU processing when it’s used… Assuming we had a way to dump it, and then get comparable results – and we don’t.

      • Let’s leave cue support for later firmwares then. Almost all the proper Saturn dumps out there are bin/cue, so IMO it would be extremely important. (and someone would end up making pre-converted torrents of full games packs if cue is not supported…)

        Very few if any tools actually dump the subcode, many just generate them. Trurip dumps have real subcode + ccd image, though!

        No games used CD+G, other than one or two audio cds. There was a Rock Paintings cd+g demo famous in the Sega CD era, I have a copy of that, tested it on the Saturn before.

        One CD+G related bug (at least I think it is), is that burned discs sometimes trigger the cd+g sequence in the CD player, that removes the nebula background and moves the VU Meters out to the side. I think this is because the system thinks there is +G info there, though there aren’t, possibly the laser making a mistake due to how very fickle subcode data is.
        I have not tested that bug with images that have real Subcode dumps, only bin/cues… Something for the todo list.

      • I’m still on the fence on the CUE issue. While yes, supporting some of the possible combinations is doable there is very little reason to do so, other than lazy users not wanting to convert the images to sane format.
        Please understand that having the CUE burned on to a real disc fixes most of what’s wrong with it. Because burning software and/or burner HW will do that. In emulators you have all the power of your PC CPU to deal with it. Not in Rhea. You either use a good file format or suffer issues.

        As for the CD+G bug, I’ve seen that happen using Rhea. Happens randomly during audio playback in BIOS and I’m pretty sure my bitstream output for R+ subs is clean.

  6. I’ve just check my saturn, its a 21 pin model so i will wait for the final version.

    Am i right to assume that all saturn models with Round power and reset buttons are all 21 pin?

    • Oval models can be 20pin or 21pin depending on when they are made.
      Round buttons are all 21pin, but there are different generations of those as well.

      If you want a 100% 20pin model, import a HST-3200 japanese machine, they all use VA0 boards, and they made over a million of them.

    • I did make a video of Rhea V1.5 booting and running Guardian Heroes US version – but that video is private. Long story short, that room is one big mess right now and I don’t want to show it🙂

    • More or less. I had some science done to it, now it’s pretty ugly with wires all over and one more chip added. Hence V1.5, not the original V1. But it works great🙂

      • And this is the most important thing🙂
        Anyway, I just checked my two PAL Sega Saturn and they are 20 pin.I’m wondering if your Rhea 1.5 can be adapted to a 20 pin Saturn with a bit of hackery.

      • With enough soldering the 1st and 2nd gen of 21-pin drives would work. Not the latest 3rd gen one though.
        In general – if you have only 21-pin models it’d be best to wait for the improved Rhea version.

      • OK, thanks.I presume pinout is very similar between 20 and 21 pin version.
        Anyway, if final version will take long to come out, I could choose also this possibility, for me it’s the same.

        How can I recognize 3rd generation of 21 pin Saturn?

      • >How can I recognize 3rd generation of 21 pin Saturn?

        Motherboard revision is VA10 or higher, and the drive has a white stripe on the edge. These last version drives come in flavors of JVC (common) and two different Sanyo (rare).

        Drives in Skeleton Saturns are all guaranteed to be such.

  7. Is there away to tell which pin connector your Saturn is without physically opening it up and looking?

    • The only sure way is to open it up. Especially for JP region saturns. However, if it’s a model with round (not oval) buttons and no CD access LED then it’s likely to be 21-pin one.

    • Provided that the case of the machine was never swapped, you can tell the board version from the serial number of the machine (NOT model number). There are many guides for that, and also a list of which board versions have which drives – do a search on the sega-16 forums.

      Opening them up is the 100% sure way, of course.

  8. I’d be interested in an early 20 pin model if any of my Saturns support it. I’ve got 2 white model 2 Japanese Saturns. I’ve also got a black model US Saturn that doesn’t read discs, I wonder if this new device would resurrect it. I’m not 100% sure the laser is the problem on that one, because it doesn’t even show the boot animation and goes straight to the CD screen.

  9. I believe I have a 20pin Saturn (its chipped already so soldering is not a big deal) I’d have to check when I go back home this holiday season. I’d be in for an early run if so. As for re-ripping disks, a bit of a bummer, but probably a good time to do it again. Its been almost 6 years since a large re-dump, might be exciting again.

  10. I know everyone hates this kind of questions, but i just can’t resist. How much do you think this 20pin-only prototype going to cost? Is it going to be cheaper or more expensive than GDEMU?

  11. i will have to dig up my saturn and open it to see if its a 20 pin if its im in for an early production hope its a 20 pin

  12. I have a 20 pin system, so I’d be happy to buy a first run model without support for a 21 pin drive. I’d likely also pick up a 21-pin model down the road.

    I’d be careful about selecting the mode simply using solder pads. I know too many people who didn’t know what they were doing and completely destroyed Saturn mod chips, due to the need to short pins in certain configurations. I think you’d be opening yourself up to a bunch of complaints\returns from people who shouldn’t be anywhere near a soldering iron without proper instruction.

  13. My opinion:

    Wait until it’s as universal as can be (20/21 pins). Two wires to solder isn’t a big deal, every modchip also got this. Jumpers/switch are better than bridging solder pads.

    Can’t wait for this!

  14. Hello
    I wold be pleased to be one of the owner of the first gen Rhea.
    First, because i htink it encourgage you in your work🙂
    The best would be to bundle it with a GDEMU !

  15. My Saturn is a late model-1 (oval buttons) with a JVC 21-pin drive, so I’ll have to wait for a universal Rhea. As for the solder pads, that’s entirely fine – as mentioned by another commenter, the universal modchip has solder pads to select around that very issue. Of course it also has 4 ribbon cable mounts (2 in, 2 out for both 20 and 21 pin) so there’s that to consider too.

    Obviously you can request preference upon purchase and solder the pads for the client if they are unwilling to configure them themselves though.

  16. I’m ready for my gdemu equipped Dreamcast to have a companion sitting next to it on my shelf.

  17. My opinion:

    1) I would wait for an universal solution before buying, although I would buy a 20 pin if you’d say an universal solution is impossible. Depending on the country you live in, finding a Saturn of a specific model may be a pain.
    2) I don’t care about image format limitation. Since it supports at least one one image I can convert to, that’s enough.
    3) I’m OK if it requires soldering and due that I’m unable to put the original CD drive back easily.

  18. I have to say to release a limited 20 pin verison to test them out . And then release the final Version (ps. I know a 20 pin😉

  19. I’m down for a 20pin prototype! I have a few different Saturn models and around 100 games I can dump and test.

  20. I’m kind of bummed that you are only looking into supporting non-open file formats. I’m exclusively a Linux user and would rather limit my usage of closed source programs when backing up my games. Do you have a link to CDI or MDF documentation in case I need to write my own tool?

    • No docs other than what’s available to find on the net. Also, there aren’t really any “open” formats that are both good enough for raw dumps and small CPU friendly. Try to parse XMLs with just 1kB of free RAM for both file read buffer and the resulting data structures and see how that works out for you🙂

      If you’re serious about writing your own too, look into libmirage-3.0.2


      • Neat, this is sort of what I was looking for. It would be great to have a convenient way to handle CDI ripping/burning on Linux.

  21. At the moment I only have 3 Saturns with round buttons, so I guess they are all 21 pin. I haven’t opened and checked yet.

    I’m getting an oval button grey Japanese Saturn soon. What are the chances of that being 20 pin?

  22. Awesome progress in such a short time DK🙂
    As far as dumps go – most of mine are ccd/img/sub, but these can easily be converted into CDI so no worries there. I’m sure that once Rhea is available then it won’t be long before a new dump collection becomes available in all the usual places either.

    I think a universal device if possible is the best way to go as it would keep your costs down (I’m sure making 4 separate devices would be costly)
    If a universal device is made then connecting solder pads would be fine for most (people have to do this on some modchips anyway) and besides some soldering would be needed for power anyway.
    Jumpers are also good and cheap to replace if they develop wear🙂

    That being said – the progress on the 20 pin is awesome and these machines can be found really cheaply (especially with drive errors)
    I like many others would gladly buy another machine just to be able to use Rhea

  23. i open up my model 1 oval button saturn but its a 64pin ic with 21 pin cable so i will have to wait

  24. Can’t believe how simple it is to create a backup .cdi image with discjuggler. I always thought there was loads of esoteric stuff to learn in order to backup games. Just put in Pulirula, selected to make a disc image, selected output file destination and name and pressed start. Three minutes later, a .cdi image was born…

      • Indeed. Sadly, my disc 4 of Panzer Dragoon Saga has some inconsistencies copying in RAW, due to a scratch on the edge of the disc. It was not severe enough to halt the process, and hopefully it would still work with Rhea. My copy of Astal didn’t even get past 22% in RAW – very badly scratched. But copied fine in DAO/SAO…oh well…

  25. I have just checked my PAL Saturn and its a 20-pin model so i would like to try out this device please. Any ideas when they will be for sale?

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