More Sega Channel prototypes dumped.

Discussion in 'General Sega Discussion' started by Kiddo Cabbusses, Jul 20, 2011.

  1. doc eggfan

    doc eggfan

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    Had another go at trying to dump from my tototek flasher and no luck. Anyone willing to take these off my hands to do some dumping?
     
  2. Since it's safe to say there's data in the cart of some kind at least, I guess that begs the question "What causes the ROM dumping process to fail?"

    Do you think it's anything troubleshoot-able?
     
  3. doc eggfan

    doc eggfan

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    It's more that my equipment is not designed for dumping, only specific for flashing the tototek cart. Either I need to get some proper dumping equipment, or just send it to someone who has the right equipment.
     
  4. ICEknight

    ICEknight

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    Perhaps somebody at the MESS forums can properly dump it chip-by-chip?

    I'm actually in talks with Sunbeam about chip-dumping a few Mega Drive cartridges of mine, so he may be able to do this one too.
     
  5. I would hope we could dump it in a less-risky manner. I've suggested a retrode a few times before. Do we have anyone with one o them?

    I suppose if push comes to shove, I can purchase one myself just for this.
     
  6. Meat Miracle

    Meat Miracle

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    Contact Retrojunkie. He has a Willem programmer, which can be used for roms, he already released a lot of stuff found in old PCs and some devkits and such. More importantly he lives in Australia so postage should be cheap and safe.
     
  7. ICEknight

    ICEknight

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    I do have one, but I don't think it will work for this device. The Retrode seems to have been designed for working with the cartdrige types that were already fully documented at the time, so it won't even work with an original Turrican cartridge for example.


    Also, I've been assured by Sunbeam that his ways of dumping the chips one by one* are not risky, or else I wouldn't be sending my stuff when I get ahold of it. I believe he's already done many of the "split" games you can see in the MESS list without problems, and I'm sure they'd love to investigate the new ROMs.


    *Then again, he's probably using the same device that Meat Miracle mentioned.
     
  8. Rika Chou

    Rika Chou

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    Just thought I would mention that the US sega channel is undumpable with the CD transfer cable and my "mega beckup" dumper, so the normal cart dumping methods might not work with this.

    Anyway this looks very interesting, thanks for sharing. :)
     
  9. doc eggfan

    doc eggfan

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    [youtube]http://www.youtube.com/watch?v=EnHJwdO6W6s[/youtube]

    Proper video capture this time. Captured every screen I've managed to see. Near the end, you can see where I've hit the menu button and reset, but the first 2 screens are bypassed and it remains on the sonic and tails loading animation.[/quote]
     
  10. Now that we got the better video capture, I think it's kinda odd that Sonic's sprite in the Channel select menu has such a thick outline. It's almost like he's Sonic Shuffle cel-shaded.

    Also geez WTF, cropped crouch sprite? I'm HOPING that's a ROM corruption issue of some kind and not Sega making a really dumb screwup.

    EDIT: BTW, comparisons between that initial channel select and the strange menu shots that look like magazine scans show similarities, mostly in the fonts and background.

    [​IMG]

    [​IMG]

    If the menus aren't already in the ROM it might be a trivial matter to reconstruct them with these references.

    Although one notable difference is how the SEGA logo in the background is rendered... but it's tough to tell whether that'd be an actual change, or it's just a matter of magazine mockupery.

    The Sega background is also very similar to the one in Game no Kanzume, btw.

    EDIT AGAIN:

    ... By the way, the copyright is 1993/1994?

    When exactly did Sega Channel get released in Japan?
     
  11. Moonlit

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    Hello chaps and chapesses. I don't know if you guys specifically want to reproduce the service or are just looking for dumps, but I know a few people have expressed a wish for some sort of revival or emulation of Sega Channel. I've been considering potential methods of reproducing at least a facade of the Channel for a few days now, and while it's not within my ability (or necessarily even the realms of likelihood) to reproduce an RF signal which the original modem cart would accept and be able to make use of, I think it might be possible to construct something resembling a functioning example.

    Here's my reasoning: we can't make the original Channel carts do anything because they lack the menu structure and game data, but we do have examples of that data in the demo cartridges, albeit pre-release versions in all the dumps I'm aware of. So what if we could patch this data on the fly? What if we took those demo carts, either intact or, in an extreme case where somebody is seriously badass at ROM hacking perhaps with bits of the Japanese variants (how come they get the cooler Sonic intro?), and when the cart pulls the menu data we replace it with something else? This does mean producing a custom cart (any possibility of some kind of passthrough/Lock-On which could use intro data from the official Channel cart?) but it's as good as any shot we've got, in my opinion, lacking anything else to work with.

    I've done some brief experiments under emulation in Exodus, tweaking RAM and ROM values, and it is possible and indeed trivial to edit menu page titles, menu items and news scroller text. How far it's possible to modify these without jumping around to custom locations in memory I don't know, nor do I know whether the structures in the demos are of a fixed length, it may or may not be possible to create an arbitrary menu structure. I tried "patching" the ROM in Exodus' ROM editor to jump back to the start of the ROM, essentially causing a reset, but I was only able to trigger it when the menu data was read into RAM by setting a breakpoint at that point, then adding a JMP instead of letting it continue pulling the data to populate the menu. Now, this isn't to say it's not possible to jump back to the start of ROM - or SRAM, where a game might be downloaded to - after the fake loading screens, it's moreso that I'm barely a beginner when it comes to assembly and low level hacking like this. I don't know whether the demo sets anything up to say which game has been chosen, but if I had to guess I'd say they were likely quite lazy when hacking out these demos, so that may have to be added.

    But that's my basic concept anyway, what do you guys think, doable? It probably wouldn't involve the stock Channel cart, and will probably require a repro cart, which I understand is likely to cause division of interest and enthusiasm, but given that we don't really have anything else to rely on in trying to preserve this service, it seems like a reasonable potential option. The idea could possibly be adapted to load games from flash carts like the Everdrive or possibly even genuine multi-game carts, I haven't investigated this yet, but it seems viable to me.

    What say you? Good idea? Bad idea? Utterly unworkable? Too far from the genuine article?
     
  12. I want to wait until we learn all we can from a dump of the Japanese BIOs before I move on to something like that - it's possible we can unearth something in there that we couldn't from the US Sega Channel BIOs carts that'd be helpful.

    Anyway, I'd imagine it'd be simple enough to replicate the Sega Channel in regard to being a service and looking superficially similar, although I bet it'd be a lot easier to use a Wifi setup than the ol' RFs. The menus from the demo cart are very similar to what I remember from my personal Sega Channel experience, so it'll certainly tickle the nostalgia bone - the major missing pieces are some specific Sega Channel exclusive versions of games.
     
  13. Moonlit

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    Yeah, I hadn't specified what the intended method of actually loading games would be because that's really a minor detail in the scheme of things, whether it be wifi, ethernet, even bluetooth, perhaps SD cards, the important bit as I see it is making the menu system function.

    I agree that there's a chance there might be something useful in the Japanese cart, and here's hoping there's something in there, but I don't think there's any harm in looking at potential options whatever the case. I do think that whatever happens though, the old RF system used on the proper carts is probably going to be forever redundant though, I can't see there being a very high chance of happening to stumble across the protocol, though it'd be nice if some docs happened to surface to make it possible.

    As for the exclusive titles, there are a few which exist in modern compilations and on the Wii VC, no? That'd be a good start. Then again, if the main desire is to preserve the experience of using the service, not necessarily the exact contents, then just having the menu load more common games would be sufficient.
     
  14. doc eggfan

    doc eggfan

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    Big Thanks to Retrojunkie!

    [​IMG]

    BB40010501.bin (512 KB)
    https://mega.co.nz/#!dkIC2Y7b!d6uWWUll_GCNqHZubsskGAiXzwkokZBnnw0Ge36gShE

    [​IMG]

    BB40002456.bin (512 KB)
    https://mega.co.nz/#!pwRgCDpA!C6j0zTIixuRISEW8zx0Dt0koC0QWkoB1feiG2tk44zE

    [​IMG]

    [​IMG]
     
  15. Overlord

    Overlord

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    I just Trial'd him, anyway =P Least I can do for getting us these dumps.
     
  16. Awesome, doc eggfan and RetroJunkie! :D

    I'll be attempting to look into it (Poorly) shortly!

    EDIT: I attempted discussion on this on #tcrf but it seems people aren't certain that the dump is proper.

    If there's a more specific processed for this, it makes me wonder if the US BIOs were dumped properly considering....
     
  17. Meat Miracle

    Meat Miracle

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    That's *exactly* how it was dumped.
     
  18. In that case I assume that would probably be an unorthodox ROM format is throwing standard protocol off. Apologies for any unneeded concern. (This kind of confusion happened with Satellaview ROMs for a long while before there was enough research to actually tell what was a misdump or hacked ROM.)
     
  19. First up, I'd like to apologise for the confusion. It seems that the GQ-4X programmer isn't up to the task of reading μPD23C4000 correctly. It seems to get some of the data but there are definitely issues with the code (like the way the checksum is different on each dump...)

    When they first dumped I though, geez that was easy! As they reported the same 2.11 version I figured I'd compare the two and was waiting for "Documents are Identical" only to be presented with a "Calculating Differences"... that wasn't right! So I tried redumping them and had different checksums again and again and again... The GQ-4X reports it can do D27C4000s, which are pin compatible with the D23C4000 maskroms.

    Bad_Ad84 concurs with you Kiddo, and is willing to dump them through a programmer with a value 10x that of my GQ-4X. If Dr Eggfan has no objection, I'll post one or both of the chips over to Bad_Ad84 - He's a wizard at all types of chips, not just a hobbyist like myself. Still it's a lesson learnt for me as I've never come across 23C type chips before. Now I know they aren't quite right on the old GQ-4X programmer.

    In summary, throw out those ROM dumps, they are all bad (and varied) as the checksums will confirm.

    And again, sorry for the confusion!

    Edit: Here's some more high resolution photos of the carts:
    Photos of unit 1 [Serial: BB40002456]
    Photos of unit 2 [Serial: BB40010501]
     
  20. Hmm...

    No one wants to go back and check to see if we went through similar with the US BIOs ROMs, do we...?