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  • Joined: 11 Dec 2009
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  • Location: Canada
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Sega Saturn Memory Cartridge Interface
Post Posted: Sun Feb 06, 2011 11:45 pm
Hey Folks,

I'm going a little bit out of the 8-Bit domain here, but I was hoping some of you may have heard of or seen some specs on this particular interface that I have been looking at.

The interface in question is one for the Memory Cartridges used on the SEGA Saturn consoles. I took apart one of these "ACTION REPLAY PLUS 4M" cartridges and found
the circuit board shown in the pictures below.

Notice the TAB contacts at the top edge of the cartridge. Looks almost like some kind of adapter would connect to this for interfacing.

I then saw I picture that I found online where there was a Parallel interface connector plugged into the top of one of these cartridges.
Apparently there is a game development system made for the Saturn that interfaces special cartridges to an ISA card. See pictures below.

I'm wondering if anyone knows of any of the specs or pinouts for this particular cartridge edge in question. I guess it's for connecting a DB25 connector
for this particular Interfacing system.

Anyhow I'm hunting around looking for some specs for this particular memory cartridge. It would be interesting to interface to.

Any info would be appreciated.

Regards,
-Gerry
saturn13zt.jpg (76 KB)
saturn13zt.jpg

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  • Joined: 27 May 2008
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Post Posted: Mon Feb 07, 2011 10:05 am
You could take a look at http://segaxtreme.net/community/forum/12-saturn-dev/

I think there's some info on the PAR+ there, though I can't recall the names of the threads.
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  • Joined: 31 Jan 2011
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  • Location: Iowa, USA
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Sega Saturn USB DataLink
Post Posted: Mon Feb 07, 2011 9:34 pm
You may want to email the author of the Sega Saturn USB DataLink project. He provides modifying AR's without the connector $15. Though, I'd guess he'd be willing to give you some information, but that's just a gut feeling.

I don't have enough posts to post the link, but you should be able to find it using Google and searching Sega Saturn USB DataLink.
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  • Joined: 28 Sep 1999
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Post Posted: Mon Feb 07, 2011 10:25 pm
There's an official schematic for the Saturn somebody scanned detailing the cartridge connector. I'll see if I can dig it up for you.

The area at the top is for a DB25 connector to interface to an ISA Comms Link card. The Comms Link connector pinout/signaling is not compatible with the standard parallel port. I made an adapter to replace the Comms Link card with USB:

http://cgfm2.emuviews.com/elec/comms.php

That particular cartridge is a clone of the Datel Action Replay with enhancements by EMS to add 4MB RAM for games that use it. The PAL in the upper right controls the basic Action Replay hardware (Comms Link I/O, Flash), and the larger one on the left controls the DRAM and cartridge ID register.

What's missing is a 74HC245 below the connector on your board. Some people modify the boards to support the 1MB RAM and 4MB RAM IDs too, and some variants have a built-in switch.

Unless there's something I'm unclear on, adding the DB25 connector and 74HC245 should cost you much, much less than $15. :)

The Comms Link interface is used for running cheat-finding software on a PC by downloading system memory during a user-driven cheat search process using Datel's software. But it's just as useful for developing software and running tests.
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  • Joined: 31 Jan 2011
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Post Posted: Mon Feb 07, 2011 10:43 pm
Charles MacDonald wrote
Unless there's something I'm unclear on, adding the DB25 connector and 74HC245 should cost you much, much less than $15. :)
Yep, I assumed as much. Most likely it's to make a little extra cash from the labor of adding the DB25 to the cart.

--Edit--
BTW, I really should keep that link handy for when I get an AR card for my Saturn.
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  • Joined: 11 Dec 2009
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Post Posted: Thu Feb 10, 2011 2:38 am
Thanks for all the info guys!! Great info to check out.

Charles,
That USB interface you made is Awesome!

So you think I can use your interface with this "Cloned" Action Replay cart I have here?

Is the wiring between the Action Replay cart and the USB board of yours pretty straight forward?. Any particular pinouts I should be aware of?

I'm thinking I may build this over the March Break, looks like a really fun project! :)


-Gerry
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Post Posted: Thu Feb 10, 2011 5:43 pm
Here are the Saturn schematics, finally found the link:

http://www.4shared.com/file/l_gk5y3j/Saturn.html

Quote
So you think I can use your interface with this "Cloned" Action Replay cart I have here?


Assuming they didn't change the software that's in the Flash, absolutely. You could always desolder it and write something else in a pinch.

Quote
Is the wiring between the Action Replay cart and the USB board of yours pretty straight forward?. Any particular pinouts I should be aware of?


Are you going to skip soldering the DB25 connector and connect a ribbon cable directly to the solder tabs on the top of the board? If so I will make a proper pinout of the tabs for you as they relate to the USB board.

Otherwise if you add the DB25 then it's all very straightforward. The cable on the board has a 2x25-pin IDC header on one end and a DB25 IDC connector on the other.

Quote
I'm thinking I may build this over the March Break, looks like a really fun project! :)


If you use the PCB layout (I wouldn't) you may want to widen things a bit so the parts aren't so cramped together. I had to so another design could fit on the same PCB. Conversely I could make proper schematics for the board if that would help.

Feel free to e-mail me if you have any questions about building this thing. Before we go too off topic. ;D
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Post Posted: Sat Mar 12, 2011 8:49 pm
Hey Folks,

I just got the parts in from my last bulk order, and slapped on the DB25 connector along with the 74HC245. Now all I have to do is find the time to build the USB board.

Hopefully sooner than later.

Talk to you all later,
-Gerry

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Post Posted: Sat Jan 07, 2012 3:33 pm
losinggeneration wrote
I assumed as much. Most likely it's to make a little extra cash from the labor of adding the DB25 to the cart.


Exactly. That cost is mostly for my labor (soldering down the chip & connector, milling slots in both halves of the case for the connector to stick through, testing, shipping, ...ect).

It may be a moot point though, as it looks like the pcb has been revised yet again!

I opened up an ARP cart for modification recently. When I opened it up, to my surprise, they have changed the circuit board design radically. They completely got rid of the ability to add a communication connector. See here for a look at the difference (the new board rev is on the left).

This is very discouraging. I didn't think that they sold enough of these to warrant doing a pcb re-design, but I was wrong.
ARP_New_PCB.jpg (354.98 KB)
ARP_New_PCB.jpg

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Removal of port.
Post Posted: Tue Jun 14, 2016 12:38 pm
Hi guys sorry to drag this up but now these ports are no longer used can i remove it? The flash is done and i want to put the pcb in a skellington cart to match my saturn.

Thanks for your time.
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