Thursday, June 2, 2016

More HDMI-ifying your Consoles, the UperGrafx for the NEC Turbo/PC Engine Systems

Today I found out about an upcoming Japanese product called the UperGrafx. The UperGrafx, as its name suggests, is intended to be used with a NEC PC Engine. What it does is it upscales the native PC Engine graphics (typically 256, 320 or 512 horizontal pixels by 224 or 239 lines) to the 720p resolution (1280x720). It plugs into the back of the PC Engine, Core Grafx or Core Grafx II, where there is a 69-pin expansion connector. It has also been confirmed to work with the US TurboGrafx-16 expansion connector. It won't work with a PC Engine Shuttle or any of the handhelds, Duos or the SuperGrafx.

Although the Expansion Connector supplies the analog RGB signals, it also supplies a lot more video information. The UperGrafx takes this information and builds a digital picture, then upscales it for the 720p resolution. The UperGrafx works similarly to the NESRGB and HiDef NES Mod.  

The PC Engine has sixteen sixteen color palette entries available for backgrounds and sixteen sixteen color palette entries for sprites. The first color entry of all background palettes is set to the universal background color and the first color entry of all sprite palettes is set to transparency. This gives a maximum of 482 colors on the screen at once. The Expansion Connector is constantly outputting these palette indexes on a separate video data bus that usually goes to the Color Encoder chip. Unlike the NES it also has a special signal to distinguish sprite palette indexes from background palette indexes, so you can still view the native video signal. The PC Engine displays 9-bit RGB for 512 colors maximum. The UperGrafx must be able to snoop on the color values stored for each palette index like the NES mods. The full CPU address and data bus is available on the Expansion Connector, so the color values for the palettes have been available. The result, when combined with the dot clock and sync signals, can give a truly digital representation of the screen image. Even better than the NES is the fact that there is no need to guestimate a composite to RGB palette.

There is a minijack next to the DVI port, which would suggest that audio is passed through from the Expansion Connector. The Expansion Connector supports stereo audio. The audio is output through the DVI connector, which is something of a pseudo-standard. Essentially the audio must be converted from analog to digital inside the UperGrafx.

Finally, the unit acts similarly to a Hudson Tennokoe 2 Backup Unit or a NEC Backup Booster. It allows you to save games to battery backed RAM instead of using passwords for those games that supported it. Unlike the original devices, there will be a USB port which you can use to transfer saves to and from the UperGrafx. The original devices came with 2KB of RAM, I do not know how much RAM will be available for the UperGrafx, but it is likely to have more RAM than the old devices.

The greatest benefit to the UperGrafx is that you are getting a pure digital video signal. There is no analog to digital conversion or degradation. There is nothing like jailbars induced by analog noise. When I had an RGB-modded PC Engine Duo last year, I could observe alternating bands of light and dark areas in the green background of Bonk's Adventure through RGB but not through composite. This cannot happen on the UperGrafx.

The second greatest benefit to the UperGrafx is that you do not need to mod your system to get perfect quality video out of it. The original PC Engine and TurboGrafx 16 only support RF output and the Core Grafx only handle composite video. No NEC console handles RGB without a mod, and there are more than one school of thought about what the perfect RGB mod should be. The unit I was using last year had a mod from doujindance, who has an excellent reputation for modding within the PC Engine/Turbo community. However, given the banding in his RGB mod, there is room for improvement.

There are some downsides. First, there is no passthrough for the expansion connector, so you cannot connect a CD-ROM unit. Second, you need a DVI to HDMI cable if your TV or monitor does not have a DVI input, but they are pretty cheap ($5-10). Third, it only upscales to 720p, not the more common 1080p of higher end displays. Fourth, it attaches to the back of the console like an "L", sticking straight up into the air, and there is nothing but friction keeping it attached to the console (not unlike attachments for the ZX Spectrum). Finally, it always displays "UperGrafx" in the borders of the frame, which some people may not appreciate.

So, for the suggested retail price of ¥40,000/$368, why should anyone buy this unit over a Framemeister? The Framemeister costs just as much and can work with almost any system. Also, if you buy this modern version of the Turbo Booster http://db-electronics.ca/product/dbgrafx-booster-ttp/ for $65, you can get the highest quality analog signals (RGB + CSync, S-Video and Composite) at a fraction of the cost.

You can see Jason of game-tech.us test the device and give his initial thoughts here : https://www.youtube.com/watch?v=b4baUgr0Ym0

A pure video of the DVI output for the device is available here : https://www.youtube.com/watch?v=LN3L1mLRWhs

Here is more information and pictures about the device, translated from Japanese : https://translate.google.com/translate?hl=en&sl=ja&u=http://www.gdm.or.jp/crew/2016/0423/159899&prev=search

The guy who supplied Jason with the device says that the lag on the device is between 0 and 1 frame. By comparison, kevtris' Hi-Def NES gives lag in the 2-4ms range. One frame is 16ms. The Framemeister gives lag in the 16-24ms range, depending on the settings used. But both the Hi-Def NES and the Framemeister support 1080p. The UperGrafx and the AVS only support 720p. What processing speed advantage given by the pure digital signal may be taken away by the upscaling done by non-true 720p displays (I am not even sure if there is a such thing as a true 1280x720p display). Lag comes from many sources and is quite insidious. Given the large number of shmups for the Turbo/PC Engine where timing is critical, maintaining a latency of well under one frame per second is essential if you want to buy this device over a Framemeister.

3 comments:

Leon Kiriliuk said...

If you truly want lag free experience for your shmups, playing on a CRT is your only option. Acquiring a PVM/BVM or modding a CRT for RGB will always give you 0 lag.

Raifield said...

@Leon

I was just about to post that! Though finding CRTs are getting increasingly difficult/expensive. I was lucky enough to snag a 36" CRT television from a relative, which I imagine my NES really appreciates, if it could feel.

Bustagi said...

CRT ALL THE WAY!!

the modder voultar hes really helped a lot of people breathe life into their old tvs with his rgb mods & technical knowledge. go find his threads! hes really made it possible for gamers to find good use in their old tvs. glad I didn't throw all mine out!