Design work started on the cart PCB. Most of the schematic has been drawn up. The card edge connector is missing, but I think Brian or Gerry may come through with that soon. Then, I think Gerry will lay out the PCB based on the schematic and etch a prototype. This will allow me to perfect my VHDL code that will run on the cart.
I’m feeling real good about this. I gave Gerry an early untested version of the VHDL and said that I think there’s about a 15% chance that it will just work on the first try.
Once the prototype works, then we can fab a real board based on the same design.
Last night I cut up a couple PCI slots to make NGP cart sockets. The process of making multiple at a time is a bit easier than making one, because I can mark a couple at a time. After one is made, it’s much easier to use that as a guide to make others.
The drawback is that the faster you go, the less careful you get. At one point, I ended up hitting my finger with the Dremel cutting wheel. Actually, I think I got quite lucky that it wasn’t worse. It’s not really even noticeable today, except for a line of burnt flesh.
So, I’m ready with some sockets for when PCBs arrive. Did I mention that I ordered some PCBs? Yeah, Turfmasta helped me by drawing up some plans based on my breadboard design. We’re going to get this NGP linker working and also make the design compatible with his NeoSavemasta SRAM card. This means that the linker hardware will be dual-purpose (and probably have other uses soon-after).
I’ve been working on the theoretical side of the Flash Cart, too. I can’t do much in practice, because I don’t have any hardware for that yet, but I’m working out a design and all that.
Well, there wasn’t much for new development over the weekend. I don’t have any new pictures or videos to show off, because the things I did weren’t very showy.
On the USB Pocket Linker front, I wrestled with optimizing the cartridge dump/backup process. I put a little work into making the command-line application a bit more usable. Then I came up with a way to transfer bulk data (as opposed to a byte at a time). I believe that my final test had me back up an entire 32mbit cart in 138 seconds. That’s not blazing speed, but it’s definitely fast enough. This isn’t something people will do super often, and a couple minutes is no big deal, in my opinion.
Writing an entire 32mbit cart will be a whole different issue. To create a bulk transfer write process, the linker itself will need to be much smarter. The flash chip that we chose to base our new pocket flash cart around supports a bypass write mode. This will help with the bulk transfer, but I don’t know what we’re looking at for speed. At the moment, I don’t have a writable cart, so I can’t really test write speed. When I get a cart, if it’s under say 10 minutes to write the cart, that will be just fine, and I won’t worry about optimizing. I don’t know how realistic that is, though. We’ll just have to wait and see.
The other thing I worked on a bit was a plan of attack for the pocket flash cartridge’s logic. I know what it needs to do, but I hadn’t planned out a process for it. I started that, and it is currently a fairly simple design. I will need to learn more about how I can actually implement the design and then adapt the design to the implementation. Gerry promised to review this rudimentary design with some of his brilliant peers and see how they reacted. Hopefully it’s positive.
As for Gerry’s work, I know he’s been mapping out a PCB for the pocket flash cart. He has a design ready, but it isn’t quite all planned out. He’s also been analyzing some of the logic signals on the cart edge connector. I’m going to want that data so I can tweak my piece of the puzzle accordingly.
Both of us get a bit of time here and there. The project may move a bit more slowly for a while as real life takes its toll on fun. Stay tuned, but don’t hold your breath.