I've always been intrigued by the hard drive mods for the Dreamcast but didn't try them. Mostly because it seemed like a lot of wires to run to the outside of the console and working PATA drives are just going to become harder to find. I looked into using a SATA adapter and found many people have added SATA drives successfully. Many posts recommended adapters with a JM20330 and I already had one of those so I decided to give it a go. It didn't work, so I ordered an adapter others had tried and had success with. When I got it, it was a lot cheaper made than my first adapter but I was able to get it to work. One thing that bothered me though was it seemed too fragile an install to me. So I decided to build a PCB to make a more secure install. Here is the circuit: I designed the circuit to be a bit of a Frankenstein of the two adapters I had to get the best of both of them. I had to change the voltage regulators because the originals used are not easy to source. All the parts besides the JM20330 can be sourced new. The JM20330 is still relatively easy to find NOS. Once I had a working board I tried to find a ESATA panel mount that would fit well in the case but unfortunately I couldn't find one I liked. So I decided to make one but as I don't have a 3D printer I just used two PCBs. So here's my ESATA adapter: Dreamcast SATA adapter: https://oshpark.com/shared_projects/frOjkyfx ESATA mount: https://oshpark.com/shared_projects/fhvrxwMw FFC to ESATA board: https://oshpark.com/shared_projects/eoyYflEJ (optional) FFC to SATA board: https://oshpark.com/shared_projects/Jnlmuhcg
How do you like how the HD works with the Dreamcast? As in the mod works/the software is well made/games work as they should. Is it pretty easy, like the original Xbox, to get games/homebrew running? I am familiar with PS2 games not liking the HD as well. Is there some playing with settings to make games work? Love your work!
It is nice when people share their PCB designs. It is a boon for someone like me who has tried and failed miserably with schematic/PCB design software.
So far it has worked quite well for me. The loads times are pretty quick. This adapter is basically a G1-ATA with a SATA adapter and so is meant to be used with Dreamshell and should have the same compatibility. Dreamshell does not have 100% compatibility but it is quite good and you can find a list of the supported games at http://www.dc-swat.ru/forum/thread-2145.html I don't own an Xbox so can't compare to that, but it is a little more difficult than on a PS2 as you need either to use a Dreamshell boot disc or install a flash chip to write the Dreamshell loader to and then you no longer need the boot disc. You can find good tutorials on installing Dreamshell on youtube. I'm not familiar with the PS2 not liking some HDs but so far I have only tried one HDD and one SSD and it works with both of those. I had some trouble with one ESATA enclosure before I got the circuit finished but since then it works with both my ESATA enclosures with both my drives in any combination. That doesn't mean I can promise it will work with all drives though. Yes, some games require specific settings to load but once you know what they are you can save them so you don't have to mess with them again. The compatibility list has the settings for each supported game. Thanks. I wanted to share the whole design so anyone can suggest improvements or extend it by themselves.
Again, a very nice design, thanks for sharing. I've been working on a similar design using the JM20330 on the underside of the motherboard. The design is similar to Dreamcastfix board but with extra features. I have a couple of questions - Does the DMA speed need to be adjustable via jumpers or can it be left at 150 MB/s (110)? The dreamcast already has series resistors for the Data lines and pull up/ down resistors for DMARQ, INTRQ and IORDY, maybe these could be omitted from the design to reduced board space? Why did u use the 5V rail for 3.3V and 1.8V instead of just tap the 3.3V rail? Thanks.
I thought about making a board for the bottom of the motherboard as well but I found it more of a hassle to develop for vs the drive. I thought I might return to the idea but now I'm worried it would interfere with citrus's HDMI board. I'm not sure so I decided it would be better to make it easily adjustable and then it would be easy to do more extensive tests. Since PATA drives usually ran at either 100 or 133MB/s I figured it likely wouldn't matter over 133. I don't actually know the Dreamcast interface speed limit. If you can point to them specifically on a schematic I will look into it. But it wouldn't save as much space as you might expect, the space by R3 could save a bit but not much. The rest could save space but not board price so the significant savings would be component cost and just assembly time. The only spot I know for 3.3 is pin 1 of the connector with the mobo which is a tight spot. If I used it, it would be the single hardest solder point of the installation and with it being so important I really didn't like that. As it is now the two hardest points by the electrolytic capacitors are actually optional as one is only an anchor and the other an alt GND. Also due to the cutouts there really isn't much space to route it out of that area without making the board a bit longer and adding some more cutouts to route around the components on the right side of the board(from the perspective of the picture above). So it seemed like the 5V rail would be better. If you know of a better spot though I would look into it.
Thank you for the quick and concise reply. Yes the underside of the mobo is harder to design for and there's only 5mm clearance between the bottom shielding. I needed access to the clock lines for overclock options. Your design is really good. I may leave it set at 150 MB/s and see what happens. Regarding the series resistors and pull up/down resistors here's the ROM schematic (it's VA0 but VA1 is virtually the same regarding address/ data lines) https://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:dreamcast_rom_flash_and_io.pdf Regarding 5V/ 3.3V, I wasn't sure how much the 3.3V rail could handle so I may have to redesign to use 5V if it can't handle the extra juice (jm20330 + msata). I received an ide - msata adapter in the post (cheap Chinese brand) to study and use for formatting and transferring files. They haven't even bothered with 1.8V or analog voltage! The JM20330 1.8V pins can handle a maximum of 3V but it's shocking design practice.
@J Incredible work, my congratulations! Question could it be a photo closer to the chip? or what model is to look for it? regards
It will probably work just fine for you. Thanks, I'll look into it. Yeah, I haven't looked into the exact limits of the Dreamcast PSU but I didn't like the idea of powering a hard drive from it. It's one of the major reasons I went with just an ESATA port. Yes some adapters are definitely sketchier than others. Thanks. The chip is a JM20330 TQFP. The list of parts can be found on the oshpark links. If you still would like another pic I can see what I can do, I use a phone so the camera is only so good.
