Saturn CD Block ROM dumped

For prototypes, drag soldering works wonderfully. For full-scale production, I will probably job it out to the same assembly house that I use for the Drag'n'Derps. I always do programming and test every unit myself.

 

OK, we both use the same magic ^^
But I personally don't have enough guts (and cash) to start full-scale production ... I suppose I should first sell few "half proto, half production" carts and see the worth of my project before producing in large quantities

 

jhl, I did not realize the issues with prepayment, etc.

Take your time , I guess I'm that way because of how other drive emulators have been marketed. There is a small window of opportunity to get them, then there gone.

I just want to make sure that I'll get one. Looks like thats a strong possibility. Thanks for all you hard work, brains and dedication to this project.

 

@jhl
I just realized you were working on a card for the mpeg slot to boot games off sd cards.
VERY INTERESTING!

I got two questions:
- Would this work with an AR? (for region-free/backup/ram)
- Do you have an idea of the price you could ask? Just a ballpark estimate would be fine.

I've not buy a Rhea yet because the euro conversion makes it very expensive for me and now I might even delay that further!

Thank you!

BTW, congratulations on getting your PhD!

 

Well, the menu software already has region-free mode... and since it has access to the USB drive you could use it for backup to USB too. But yeah, I think those would still work if you still wanted them.
RAM works fine, I played a bit of Metal Slug with it the other day.

That's actually a really hard question, especially since the final form hasn't been locked down yet. It'll depend on quantity, as well as whether I end up making injection moulded plastic shells (rather than distributing a bare PCB). Ballpark? I don't think I can say more than "<=100USD" at this point.

 

I'm not sure if plastic shells would work. There is only very thin space available around the cart connector and the EMI shielding. If you make the shell too thick, it would scrape against the metal, and if you make it too thin, it would be fragile. I imagine that's why the MPEG cards came with a metal cover, and making those for your cart would surely end up prohibitively expensive.

However, you may want to design your card in a way so you can re-purpose the cover of a video cd card... I have two dead ones who'd be perfect donors.

 

I've been keeping an eye out for news on your MPEG card slot project. I hope when you get to the point of production that there will be a thread that I won't miss. I really like the project idea and what it could be.

 

I'd think the card slot door would need a mold to cover it up, since the door is being removed?

There are Saturns that don't have the MPEG slot?

 

Will be buying this for sure! Will it work along side a modchip? I assume it shouldn't be an issue.

 

Or you can leave it off, or cut a hole in a spare door, or etc etc.

Hi-Saturns, for one. Also the wacky karaoke one, though it has a footprint on the PCB for the MPEG connector so you could probably add one...

Your assumption is spot on

 

Hi-Saturns definitely have MPEG slots, I have one. They are all normal Saturns with a custom boot rom only, but they were sold with an MPEG card bundled, so most of them have the slot occupied by a card (you can just pull them out and replace them).

The only Saturn I know of that doesn't have the MPEG slot is the SKC-1000C. The non-C variant, SKC-1000, still has it - but you have to disassemble the entire thing to reach it, which is incredibly difficult (15+ boards stacked in various ways), and I'm not even sure if there's space for the card to fit anyway. Even the SGX has a slot on the back for inserting the card. The Hi-Saturn Navi has it too. And every other type of Saturn is a stock unit with at most a custom cover and/or boot rom.

So yeah, this should fit inside every type of Saturn. Except the SKC-1000 karaoke commander, there you have to use a Rhea or a modchip to run backups.

A question, will your card be able to fit with a card inserted, behind the battery door? As in will everything fit in there behind the door, or will the card stand out so much that you have to remove the door? It's a minor concern considering how much functionality your card will add, but I so hate it when I end up with consoles with missing doors.

 

Yes, absolutely: everything will be within the footprint of the standard MPEG card.

 

Update time!

I finally found myself with some spare time and energy this weekend. I ended up knocking up most of a firmware update system; the idea is it'll be possible to update firmware via the Saturn, with a backup method via USB. That way, you won't (in general) need to faff about with USB drivers and software and the like. I still need to actually test the thing, but it's all written.

The next thing I'd like to knock off is Redbook audio. That'll need a small mod to my test board and will probably involve some heavy lifting to get the timing flawless, but I reckon that'd be manageable in another afternoon or two.

At that point, I think it'll be feature complete! I can spin the board and work towards getting some beta units together.

I was tidying up my unusably messy desk today and found a notebook with some notes from the project - from over a year ago. I'm astonished at how time has been flying; my days are certainly getting shorter. I'm going to try and put time into this thing regularly again so I can finish it before I go grey

 

Exciting news!

One would think that redbook audio would be easy - just a matter of streaming continuous data (at a fixed, properly timed speed). Or am I missing something?

 

It's that simple, and that hard.

The audio stream doesn't go through the CDB CPU and its buffers. It goes from dedicated lines on the MPEG card through the ASIC and thence to the SCSP. So I have to implement the physical layer first; it's not documented, though it *should* be straightforward (apart from a bit of juju in the ASIC).
Then of course building a streaming system with good jitter and gapless performance characteristics is simple in theory and with lots of finicky trickery necessary in practice.

 

Thanks for the update, jhl. What will game compatibility be like? Are you aiming for 100% game compatibility?

 

Why would anyone aim for less?

Imagine missing out on some of the classics
http://sega-addicts.com/2012/05/05/the-sega-addicts-top-10-worst-sega-saturn-games/

 

@jhl, Any rough idea when your device would be ready? I'm really interested in it and I don't wanna miss it!

 

Going way back to the original post here about the SH1 ROM being dumped, I've got a Sophia devkit here, any interest in getting the ROM for that dumped too? I know the SH1 ROM is different, because this system happily boots CDR backups without any fuss.

 

My original idea was that once a unit is finished to the point that it is safe to ship and can dump the rom, we'd send one over to Retrojunkie to dump the early CDB roms from his Sophias. Since those units are now in your hands, I suppose we can still do it, if/once jhl is up to it.