WindDrake

I can't edit posts that old, but thanks for the heads-up. Glad they fixed it. Still seems like a lot of money for a cart.

I didn't really plan to offer these other than as a gift to the community, hence the open sourcing. I had one spare cart, but somebody snapped it up before it was even assembled. I'd love to offer a run of them or something, but I don't have enough gaps in my schedule to pull it off. Sorry!

More progress on this today, now that the labels have finally come in. First up, here's a 1.0 board with the line swap fix. Pretty low-impact, and it's been fixed on the 1.1 board. Here's the labels, printed by fireandclarity on Etsy. Labelled cart. Real deal Vs. My RAM Cart At this point I'd consider the project complete.

Reminds me of Mercs/Shock Troopers, and the music is great. Just pre-ordered.

You should be able to drop in a BA6396, which is still available from shops on eBay. If pins 5 + 6 on the PCB aren't isolated from the rest, as grounding N/C pins is common, you'll have to lift or clip those leads on the BA6396, as they added external connections to the internal 5v regulator on this IC, and grounding those pins will short out the internal regulator.

Ramtron/Cypress never made a 512k/4mbit 5v Parallel FRAM, sadly. Biggest around seems to be the discontinued FM1808, which is 32k/256kbit (stock cart was 128k/1mbit). There's I2C FRAM that big, but they are $50+ and would need a whole memory manager sitting between the parallel and serial bus. Not really worth it.

The SegaCD/MegaCD goes looking at a specific address during bootup, and if it gets the correct byte back, it'll identify the cartridge and it's SRAM size. Not sure on the other questions - beyond the scope of this thread.

Battery-backed SRAM, actually. This is a open-source implementation of the Sega CD Back-up RAM Cart. You can move savegames from the internal memory of the SegaCD to the RAM Cart for long-term backup, and many games supported saving directly to the cart. In the case of Lunar Silver Star Story, it actually requires the cart to access Act 3, due to the savegame size being larger than the internal save RAM on the Sega CD.

Hey all! Boards came in today. Had a minor issue with the '138 decoder having A20/A22 swapped by accident,. It after a quick wire patch everything is working nicely! I've already corrected the PCB files (v1.1) on GitHub to fix this. This cart also doesn't have the Dark Wizard save glitch like the Castlemania Games Ultra cart. New cart label graphics will get uploaded to GitHub soon. I'm also working with the folks at RetroGameCases to offer the labels predone.

Hey all. I'm normally over on the arcade side (same username on KLOV & ArcadeControls) but I've finally got a console project. After seeing how much that Ultra CD RAM Cart costs or the price of an original cart, I started working out the schematic from my Sega RAM cart. Then I stumbled onto l_oliveira's work on a RAM Cart over on the NFGgames forum. With a couple days of schematic drawing and PCB layout behind me, here's what I've got so far. Should be finalizing this by the end of the weekend and ordering my PCB's on Sunday. I've got a label worked up as well, just need shells, assuming I don't just print them. This is all totally open-source, with all the files available at github.com/WindDrake/SegaCD_Ramcart