Hello there. I thought I'd make a quick guide for getting the best picture out of your J-PC's using OSSC, which I still consider the best upscaler for computer use -- much thanks to its compatibility with "weird" formats like 400p @ 24kHz of the PC-98 (Update: and its bargain price point, compared to the 4k scalers that are starting to appear on the market). Whenever the topic of upscaling comes up, at least in my circles, allegations about OSSC being "a pain" or "impossible to set up" inevitably start flying; I gather most of this comes from people with little experience in actually using one, as even something as "obscure" as PC-98 works pretty much out of the box. This guide is mainly needed to fix a single quirk affecting vintage computer sources, which I see many people struggle with. After we're done, I hope you'll agree there's nothing difficult or tedious about this wonderful scaler, and you should've bought one years ago :^)

Let's start with a typical user experience. You got yourself a shiny new PC-98, and want to hook it up to OSSC; so you plug in a passive RGB (two rows of pins) -> VGA (three rows) adapter

, and run a standard VGA cable from it to the scaler's AV3 port. Then you go in the menus to set 400p scaling to line3x mode, for those blissfully crisp pixels. And voilà -- everything is perfect. Didn't even need a guide to get there. (If things didn't go as smoothly, check out the Addendum.) However, after a while, you start to notice a small but annoying noise in the signal. It's pretty hard to capture in pictures or video, but you spot it easily on PC-98's signature dithered graphics. And the more you get attuned to it, the more you see it all over the place. Before long, you really want to get rid of it...

Our problem is caused by the AV3 ("VGA") port lacking a low-pass filter, which is a component for cleaning up less than ideal signals from old devices. We work around this by rerouting the RGB signals to the AV2 ("Component") port (where the LPF does its magic), while leaving the HV ("Sync") signals plugged into AV3. There are many ways to accomplish this, but the one I tend to recommend is getting two VGA to BNC breakout cables, three BNC female to RCA male adapters (for the RGB wires), and two female to female BNC adapters (to connect the sync wires). As an alternative to buying anything, experienced users can peel some cables they have lying around, and solder in the right connectors to achieve the same result. Update: You can also buy a sync-combining VGA->SCART adapter that accomplishes the same thing using the AV1 port, which might just be the most noob-friendly option. That said, setting up the breakout cables is also very simple: One end goes to your computer, and the adapters go in as you'd expect. The three RGB wires then plug into the AV2 ("Component") port in the back of OSSC; the sync wires connect together; and the last HD15 ("VGA") connector goes into the AV3 port on the side. Here's a few pictures showing the required equipment, and how to connect everything:


All set? Good job. Now all that's left is to flick on the power, and go in the menus to make OSSC aware of our rerouting setup. The setting we want is under Compatibility: AV3 use alt. RGB. Set it to AV2. And there we go -- you should now be greeted with pretty much the best quality image from an old Japanese PC that modern technology allows ← written before 4k, 8k and 16k scalers took over. Let's take a moment to feast on some screenshots, just because we can:

(I guess the crispness of the pixels doesn't show that well when zoomed in. But if you look at the blue OSD, which looks a bit soft here, and imagine it looks 100% crisp IRL, you can see the upscaled picture looks just about as good.)

That's really all there is to it. OSSC offers a ton of advanced settings for the pixel peepers out there, but I've never felt the need to improve on J-PC picture quality beyond this point. Based on my experience with game consoles, you can squeeze an extra 5% more crispness by dialing in what are known as "optimal timings" for your system (and whatever other settings need to be correct for them to work without issues). But whether or not that is worth your time is a whole another matter. My goal here has been to show that you can skip that stuff entirely, and still get a fantastic picture quality. If you like the results, I hope you'll join me in spreading the word, as surprisingly many people seem to be unaware of this.

Finally, I have one recommendation for improved usability: Make profiles that work with as many systems as possible, to minimize the times you need to touch the remote. I've been asked to upload mine, so I'll grant that wish here. Just remember these are tailored for my specific system, and as such may introduce problems with your displays etc. I use the default profile to play everything from 8-bit NES to PS2 and DC on the console side, and from MSX to X68000 and Windows XP on the computer side. IIRC there's a couple systems that need custom profiles (separate from the default one), but I forget which ones they are. I'll probably reupload the profiles every once in a while, when I make changes to them. You should be able to load them on this site, to explore and modify the settings using a computer.

[That's all for now, folks. I'll be adding more sections, and expanding on the current ones, when I think of more stuff to write about.]


I thought it might be wise to compile a list of miscellaneous caveats, or things to look out for, which may possibly be wrong in your setup, and cause things not to function. As we've seen, setting up OSSC is pretty straightforward, but there are many factors at play here, so problems may arise from unexpected sources. Let's go through as many of those as I can think of:



Did you enjoy this guide? Be sure to check out my other ones too, by jumping on the main page. If you'd like to support my work, also check out my cheeky Patreon, which will get rolling after I finish my Dumping Guide. Thx & TTYL!