Kyuusaku
B. Jenet's Firstmate
- Joined
- Mar 26, 2003
- Posts
- 419
I'm thinking of working on a fully-digital Neo Geo HDMI A/V upgrade board. Back when I first mentioned the feasibility of this project I didn't have a HDTV, now I have a few, and a better handle on the digital signal processing for the job.
Since that post I've been working here and there on a complete Neo Geo clone, but I've had to step back since developing accurate CPU cores is very tedious, plus I haven't had the funds to prototype the ridiculously expensive hardware. This project should be a lot easier to pull-off while at the same time is probably as desirable if not more so to the community.
The mod would output 720p60 and only 720p60. The actual game would occupy a 960 x 672 window within the 1280 x 720. There wouldn't be any plans to implement full-screen scaling via interpolation since it's lossy and would require significantly more hardware. 720p doesn't always look so hot on today's 1080p TVs, but it will scale perfectly on new 4K TVs (720p x 3 = 2160p). Likewise I couldn't go down to 480p because the standard 480p format doesn't have square pixels and would require interpolation.
The 720p output would use industry standard frame timing and a literal 60 Hz frame rate, so there would be no question about its compatibility with displays. To achieve this timing the Neo Geo's clock will need to be dynamically controlled to keep synchronization with the HDTV frame, and unfortunately it isn't economically feasible to do this in a way which keeps analog video working. HDTVs are ubiquitous now, so hopefully that isn't a dealbreaker...
Digital audio over HDMI is also the plan, but I'm not sure whether it will fit into my target device, so it might come at an increased cost. This is "special" because the YM2610's SSG component (the beep-boop YM2149/AY-3-8910 sound chip) natively only provides an analog output, so it will be emulated.
The install will require soldering many wires (40+ with audio), but the points are all through-hole leads (on AES consoles), so it's quite easy if you work carefully.
My question to you is: what could I sell this for and how many do you think I could sell? 500, 1000? Is the lack of analog video a dealbreaker for you? Is the Neo Geo still valuable enough to warrant expensive video mods?
To get ready for the project I will need to buy equipment I can't afford for prototyping, so I need to know if this is a non-starter. It seems to me like the market has been losing enthusiasm for the Neo Geo as it ages, but I could be wrong about that.
Since that post I've been working here and there on a complete Neo Geo clone, but I've had to step back since developing accurate CPU cores is very tedious, plus I haven't had the funds to prototype the ridiculously expensive hardware. This project should be a lot easier to pull-off while at the same time is probably as desirable if not more so to the community.
The mod would output 720p60 and only 720p60. The actual game would occupy a 960 x 672 window within the 1280 x 720. There wouldn't be any plans to implement full-screen scaling via interpolation since it's lossy and would require significantly more hardware. 720p doesn't always look so hot on today's 1080p TVs, but it will scale perfectly on new 4K TVs (720p x 3 = 2160p). Likewise I couldn't go down to 480p because the standard 480p format doesn't have square pixels and would require interpolation.
The 720p output would use industry standard frame timing and a literal 60 Hz frame rate, so there would be no question about its compatibility with displays. To achieve this timing the Neo Geo's clock will need to be dynamically controlled to keep synchronization with the HDTV frame, and unfortunately it isn't economically feasible to do this in a way which keeps analog video working. HDTVs are ubiquitous now, so hopefully that isn't a dealbreaker...
Digital audio over HDMI is also the plan, but I'm not sure whether it will fit into my target device, so it might come at an increased cost. This is "special" because the YM2610's SSG component (the beep-boop YM2149/AY-3-8910 sound chip) natively only provides an analog output, so it will be emulated.
The install will require soldering many wires (40+ with audio), but the points are all through-hole leads (on AES consoles), so it's quite easy if you work carefully.
My question to you is: what could I sell this for and how many do you think I could sell? 500, 1000? Is the lack of analog video a dealbreaker for you? Is the Neo Geo still valuable enough to warrant expensive video mods?
To get ready for the project I will need to buy equipment I can't afford for prototyping, so I need to know if this is a non-starter. It seems to me like the market has been losing enthusiasm for the Neo Geo as it ages, but I could be wrong about that.