I knew nothing about Darksoft's cart until a quick Google a few minutes ago.
I've had a few back-and-forth emails overnight on the topic with my ex-colleague who was kind enough to review my schematic and do the PCB layout all that time ago. He has encouraged me to continue with the project despite the competition that has now surfaced. I still haven't made up my mind but I must admit, having not had much opportunity to work on retro-related hardware projects for quite some time, I've very tempted to ramp things up again. Having said that, the "no time and no money" issue is still a real factor in the equation.
What I will say though, is that my design actually had a couple of features not readily evident in the details that
neosd has released thus far. One of course is support for the AES out-of-the-box, though it's also fair to say that my product is all still vapore-ware at this point! There was another feature that I added that I won't disclose at this point, but it actually enhanced the capabilities of the Neo Geo somewhat and is therefore
very unlikely to be duplicated by someone else. Whether the enhancement is actually something anyone else would be interested I can't say, but it would only be of consequence to home brew developers specifically targeting my flash cartridge that wanted to take advantage of this feature. It goes without saying that I had a few ports in mind that would use this feature.
The flash cart itself started out as a spin-off from my motherboard project; something that I could (laughably now) produce sooner and for less outlay. I reasoned that it might be a means to fund the motherboard development, and also assist in the motherboard development itself.
Sadly (as far as this project is concerned), my circumstances changed rather dramatically over a short period of time and I found myself without the means or the time to continue. The current status is this; the MVS and AES adapter boards have been designed, manufactured, assembled and successfully tested. I have, for example, 'run' an AES cartridge in an MVS system (sans sprites of course) which has, as far as I know, never been done to this day (not that there's a lot of point to it without sprites). The flash cartridge (prototype) PCB has been designed and fully laid out - a cartridge would thus comprise two identical 'flash cartridge' PCBs and an adapter with fingerboards to plug into an AES/MVS. Note again; this is only the prototype. What needs doing is a
final review of the schematics and PCB, check again that the parts we have used are still available, and order a prototype PCB manufacture and assembly run (6-8 boards in total).
I had also planned a couple of different variants of the cart, including a low-cost 'home brew' version that was incapable of playing commercial titles but allowed home brew developers to test and even produce titles on cartridge.
As for the motherboard project; many years ago I got a rudimentary system implemented on a terASIC DE2 that booted the BIOS and played Joy Joy Kid - again sans sprites - but you could actually coin up and see the game running via the FIX layer graphics. I have a mostly-complete schematic which was ridiculously over-engineered on purpose; a massive FPGA and both MVS and AES cartridge slots. It was (is?) to be the basis of many future FPGA projects, and the carts slots make perfect I/O board connectors!!!