Need a bit of help making a Mark III adapter

[hadess]

Hey!

I have a fully loaded Retrode 2, including the Master System adapter, but I've been buying a few Japanese Mark III/Master System games which I wanted to be able to dump.

There's a couple of threads already about various third-party adapters being tested, none working from what I can tell. So I thought I'd "make" my own. Here's my thinking, and do stop me if any of this sounds wrong.

1. Find the physical bits needed to connect everything. That was relatively easy. After spending a couple of hours (!) on electronics supply sites, the cheapest way to get a MegaDrive connector on one end, with a Mark III connector on the other is Raphnet's Mark III for Megadrive adapter:
http://www.raphnet-tech.com/products/brd_markIII_to_smd/index.php
and here are the schematics for it:
http://www.raphnet-tech.com/downloads/markIII_to_smd_schematic.png

2. Let's forget the above for a moment, and find out how the SMS adapter is pinned out. I found this:
http://consolingmyself.co.uk/post/18692678762/retrode-sms-gg-plug-in-adapter-pin-out
Is this still accurate? Let's assume it is and move on.

3. We need to find out what the differences are between the SMS and the Mark III pinouts. I found this on SMS Power:
http://www.smspower.org/Development/JapaneseSMSCartridge

And at this point I'm kind of stumped as to how to use all this information. I think I'm missing an "export SMS to Mark III diagram" somewhere. Ideally, it'd support Mark III and Japanese SMS games[1], but I already see some difference in wiring for some lines that the Retrode uses (though I could have had my numbers crossed).

Any ideas? Cheers

[1]: Bonus point if I can dump those 2 SG-1000 cartridges I have

[Aleron Ives]

I'm still hoping for a solution to this problem, too. My Japanese Phantasy Star cart sits alone, waiting to be dumped. Gotta have that superior Mark III music!

[RazorX2014]

i made this awhile back, it allows me to play sega cards on the master system model 2, play sega cards on the game gear with a master gear converter as well as dump sega cards on my retrode using a master system plugin.






although ive never tried im guessing it will also do SG-1000 cards too.

@hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

[hadess]

> @hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

Well, because it didn't work

I should probably have added this information in my first post, but I had been putting off posting for so long, that I didn't even think to try and explain why I went down this path.

I have 2 cartridges that work out of the box with the adapter on my Megadrive II PAL:
- Enduro Racer (Mark III)
- Alex Kidd In Miracle World (Mark III)

Those 3 games will not boot without stack init. A trick that's mentioned on the Raphnet page is to swap a working cartridge quickly with a non-working one, while powered off. Another way, which I wouldn't recommend but works is to start the Megadrive with the adapter but not the cartridge, insert the cartridge and press Reset. Anyhoo, the 3 games:
- Alex Kidd BMX Trial (Mark III)
- Space Harrier 3D (Mark III/SMS)
- Opa Opa (Mark III/SMS)

All 5 of those are detected as 4 megs "GenericRomInSegaSlot.dat" dumps. Dumping the ROMs ends up in garbage.

There's a few active components on the Mark III/SMD adapter, where the Retrode SMS adapter has none.

Hope that clears any doubts about the reason why I'm asking

(and if you want to share your pinout for the card reader, probably in a separate thread, it'd be appreciated!)

[RazorX2014]

> @hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

Well, because it didn't work

I should probably have added this information in my first post, but I had been putting off posting for so long, that I didn't even think to try and explain why I went down this path.

I have 2 cartridges that work out of the box with the adapter on my Megadrive II PAL:
- Enduro Racer (Mark III)
- Alex Kidd In Miracle World (Mark III)

Those 3 games will not boot without stack init. A trick that's mentioned on the Raphnet page is to swap a working cartridge quickly with a non-working one, while powered off. Another way, which I wouldn't recommend but works is to start the Megadrive with the adapter but not the cartridge, insert the cartridge and press Reset. Anyhoo, the 3 games:
- Alex Kidd BMX Trial (Mark III)
- Space Harrier 3D (Mark III/SMS)
- Opa Opa (Mark III/SMS)

All 5 of those are detected as 4 megs "GenericRomInSegaSlot.dat" dumps. Dumping the ROMs ends up in garbage.

There's a few active components on the Mark III/SMD adapter, where the Retrode SMS adapter has none.

Hope that clears any doubts about the reason why I'm asking

(and if you want to share your pinout for the card reader, probably in a separate thread, it'd be appreciated!)

i recreated the markiii to smd in eagle and stripped it down a touch, the resistors on it are just 0 ohm so i could just bridge the connections:





i will have to check it out sometime but currently i dont have any mark iii cartridges or console which sucks also i did have another thread for my sega card to master system adapter on here but i want to order some proper boards for it before i post everything and currently to get the sega card edge connector you have to remove it from a master system model 1 or something so that sucks.

[RazorX2014]

ive also just done this:







this will probs be the best route to go down as it will most likely also work on a master system if your bios supports it.
as for the retrode i cant remember if its setup to recognize mark iii roms so it will most likely show up as a .sms

[skaman]

I've built a working Mark III to Retrode plugin.  I'm using a slightly modified Eagle autorouted layout PCB with the Mark III connector sold by Tototek.

I'm able to dump the two Mark III carts that I have -  Phantasy Star and R-Type.  Using the BETA SMS/GG v0.24 firmware, I'm also able to read the Phantasy Star save.

I'll post more details soon...

Here are some pictures:






I still need to cut a case for it...

[Aleron Ives]

Awesome! I've been waiting for somebody to work on the Mark III. My Phantasy Star cart is also eager to be dumped.

[skaman]

Here's a few pics with a handcut shell.




One nice thing with the Mark III Plugin is that the Card Catcher works with it.  I've tested a Sega MyCard and a Sega Card.

[hadess]

Just needs a nice sticker now

(I've made such a sticker for the SMS/GG combo, after cutting up a Megadrive case as well, I'll post it once I've actually printed it out for testing)

[hadess]

I've just received skaman's prototype. The only problem I had was that I needed to power cycle the Retrode to make it read new carts.

I successfully dumped, without any tweaking necessary (ROM size, or otherwise), and compared them to ROM dumps on the net:
Alex Kidd BMX Trial
Alex Kidd no Miracle World
Enduro Racer
Opa Opa
Space Harrier 3D

Out of curiosity, I also tested with an SG-1000/SC-3000 cartridge (yes, cartridge, not card) of "Champion Golf" but ended up with a "GenericRomInSegaSlot".

Thanks skaman!

[skaman]

I'm glad it works for you!

How does the SG-1000/SC-3000 data look if you set forceSystem to sms?

GenericRomInSegaSlot will have the data in alternating bytes.  The data should be contiguous in sms mode.

Do the SG-1000/SC-3000 carts have headers?

I'll have to read up on the SG-1000/SC-3000 carts.

Another item for the growing to-do list.

[skaman]

If anyone is interested in a Mark III Plug-in, I have some extra PCBs and I can also assemble a small number with cart connector (NO SHELL).

Contact me by PM.

[Bock]

SG-1000/SC-3000 roms have no header.

There are also board variations that present the data in different way (with slightly adjusted code):

Code Select Expand

# smspage /8 /crc "Sega Flipper.sg"
[Sega Flipper.sg]
Size: 16384 bytes (2 pages), CRC:8EFC77BC
0 ; f3 31 64 c0 ed 56 cd a4 3c 21 00 c0 01 00 04 36 ; Sum:0ADB77, CRC:76994E5B
1 ; 03 00 03 01 03 02 02 03 03 03 03 03 02 03 02 03 ; Sum:0E3874, CRC:BAECDD57

# smspage /8 /crc "Sega Flipper [40k map].sg"
[Sega Flipper [40k map].sg]
Size: 40960 bytes (5 pages), CRC:FD76AD99
0 ; f3 31 64 c0 ed 56 cd a4 9c 21 00 c0 01 00 04 36 ; Sum:0AE177, CRC:9923C1F3
  Same pages: 00-03
1 ; f3 31 64 c0 ed 56 cd a4 9c 21 00 c0 01 00 04 36 ; Sum:0AE177, CRC:9923C1F3
  Same pages: 00-03
2 ; f3 31 64 c0 ed 56 cd a4 9c 21 00 c0 01 00 04 36 ; Sum:0AE177, CRC:9923C1F3
  Same pages: 00-03
3 ; f3 31 64 c0 ed 56 cd a4 9c 21 00 c0 01 00 04 36 ; Sum:0AE177, CRC:9923C1F3
  Same pages: 00-03
4 ; 03 00 03 01 03 02 02 03 03 03 03 03 02 03 02 03 ; Sum:0E7339, CRC:6EE6531C

Notice that second version, there's technically also 16 KB of data but in the memory map exposed by the circuitry, the first 8 kb are mirrored 4 times. Some games access the mirrored regions.

They are fairly unusual, and due to compatibility reasons we decided to release rom dumps in this same format (with the duplicated 8 kb, so the .sg files are 40 KB there).

If you have any technical questions on Sega 8-bit stuff don't hesitate to post on that smspower thread (where we are), we'll happily help you.

[Aleron Ives]

I also got to put skaman's adapter through its paces today. The Retrode couldn't see the Mark III cart with my old firmware, so I updated to v0.22, and then it worked. My checksum for Phantasy Star matches the no-intro database, so I've applied the SMS Power English patch and am finally ready to experience the game with the proper soundtrack. Thanks skaman!

I'm also happy to report that firmware v0.22 is not generating USB errors in the Windows event log, so it appears that whatever USB problem was in the v0.18 firmware series is fixed now. My 3- and 6-button Genesis controllers are still working with the new firmware, so I'm not going to go back to v0.17g this time.