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My name is Kitao Nakamura, the developer of the PC Engine emulator "Ootake."

This article will inevitably end up praising Ootake a bit,
but it's not driven by some shallow "look how amazing my implementation is" kind of motive
(though I certainly don't mind if people appreciate it).

If someone wants to enjoy PC Engine titles today but can't play them on original hardware,
I genuinely believe that Ootake offers the closest experience
without compromising the quality of the games.

I've always been concerned that playing in a low-accuracy environment can diminish
the strengths of these works.

By writing about the inner workings of Ootake like this, I hope it will help raise
the overall level of the emulator scene, even if only a little.

I plan to cover several topics over the coming installments.
This time, the focus is on color reproduction.

In developing Ootake, I connected real PC Engine hardware to both CRT televisions
and modern LCD monitors, studied the output until I practically wore holes in my eyes,
and implemented the color reproduction based on
what I understood to be the original developers' intentions.

As far as I know, Ootake is the only emulator whose default settings are based directly on
how colors actually appear through the real hardware's composite and RF output.

Including commercial re-release hardware and software, most other PC Engine emulators are
built on the assumption of displaying output from a PC Engine modified for RGB.

As a result, their colors differ significantly from what you see through
the real hardware's composite or RF output.

So, which one represents the original, intended look?


RGB Mods and Expansion-Bus RGB Output Use Uncorrected Signals

By modifying a real PC Engine to tap the RGB signals directly from its internal chips and adding an RGB output port, you can connect it to any display that accepts RGB input. However, when you use this kind of modification, the resulting image ends up showing colors that differ quite a lot from the PC Engine's original appearance. ↓Ootake's default display. It closely matches the familiar look of real hardware's    video output. — There were also many televisions of that era that had somewhat paler     colors than this, due to considerable unit‑to‑unit variation. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Default Source: "Fantasy Zone" (© SEGA, © NEC AVENUE） ↓Displayed with Ootake set to approximate a modified RGB‑output unit.    The red tones become stronger, giving the image a more primary‑color look.    Because the contrast is too high, the overall color balance appears overly    harsh and garish.    In the PCE version of "Fantasy Zone", this difference becomes critical. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Gamma 0.94 , Brightness +30 , Non-Scanlined Source: "Fantasy Zone" (© SEGA, © NEC AVENUE） ↓Ootake’s default display. It has a familiar vibe, close to the video output of    real hardware.    Lilia in the Ys II opening. Even the “shadowed skin tones” in the darker areas    still remain recognizably skin-colored. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Default Source: "Ys I・II " (© Falcom  © Konami Digital Entertainment） ↓Ootake set to a configuration similar to many other emulators.    Reds appear more intense.    Unlike real hardware, the shadowed areas sink too dark, causing skin tones    and hair colors to look dull. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Gamma 0.94 , Brightness +30 , Non-Scanlined Source: "Ys I・II " (© Falcom  © Konami Digital Entertainment） Because RGB output looks sharp and clean, many people have assumed it to be "correct" without noticing the color differences. The same applies to modifications that extract RGB signals from the rear expansion bus; without proper adjustment, the resulting colors will differ from the PC Engine's original appearance On real PC Engine hardware, the video is originally displayed through the following process: Internal RGB signals → Converted into TV‑compatible video signals (colors are altered in this step) → Composite/RF output However, on an RGB‑modded unit: Internal RGB signals → Output directly as RGB with their original, unadjusted color values Because the RGB output bypasses the color‑adjustment stage, what you see is the raw RGB signal rather than the PC Engine's intended color appearance. The first PC Engine emulator ever created, "VPCE" — developed by a programmer in Germany — was implemented based on the color output of an RGB‑modded PC Engine. For roughly sixteen years after Ootake's release, nearly all subsequent emulators and commercial re‑release hardware also followed this RGB‑modded color baseline. About sixteen years after Ootake introduced a color reproduction closer to real hardware, users of the FPGA‑based MiSTer platform began noticing the differences from actual PC Engine units and implemented settings that move the colors closer to real‑hardware accuracy. In the next chapter, we will explore why, for so many years, most emulators continued to use colors that differed from those of real Japanese PC Engine hardware.

Why So Many Emulators Continued Using Colors That Differ from
Real Japanese Hardware

Why were the first PC Engine emulators — "VPCE" and, a few months later, "Magic Engine" — implemented with colors that differed from real Japanese hardware? The reason is that in Europe, NEC's officially released PC Engine models were extremely rare. Most users imported Japanese PC Engine units and purchased them already modified with RGB output ports, making RGB‑modded consoles the de facto standard in that region. The creator of "VPCE" was from Germany, and the creator of "Magic Engine" was from France. It is highly likely that the hardware they owned were Japanese PC Engine units that had already been modified with RGB output. The reason is that NEC's officially released European PC Engine models operated at 50Hz, which caused Japanese games to run in slow motion. Both of these emulators were designed to run at 60Hz — the same refresh rate as Japanese PC Engine hardware — rather than 50Hz. In France in particular, consumer televisions commonly included RGB (SCART) inputs as a standard feature. Because of this, Japanese PC Engine units that had already been modified for RGB output were routinely sold in many game shops. It is also plausible that the German creator of "VPCE" took advantage of this French market and imported not only the console but even a compatible television. Since these RGB‑modified PC Engine units were effectively the mainstream option in Europe, it was only natural that early emulators ended up reproducing colors that differed from those of real Japanese hardware, which relied on composite or RF output. Several factors likely contributed to why this situation persisted for so many years, even among Japanese emulators, including commercial ones: - The developers' own PC Engine units may have been RGB‑modified consoles. - Many developers never directly compared the colors of real hardware with those of their emulators. - Because most emulators shared the same RGB‑based color tone, it was widely assumed to be correct without further verification. - Even with inaccurate colors, games remained fully playable; darker color reproduction rarely caused issues severe enough to hinder gameplay. As a result, many games end up being played with colors quite different from what their original designers intended, preventing the true appeal of their artwork from being fully appreciated. There are, in fact, several PC Engine titles that have been unfairly judged due to this lack of accurate color reproduction. In the next chapter, we will take a closer look at these misunderstandings and explain them in detail.

Fantasy Zone's Beautiful Real‑Hardware Colors, and
Gradius's Not‑So‑Dark Appearance

As shown in the images from the first chapter, the PC Engine version of Fantasy Zone can look noticeably harsher and more toxic in color when played with the default settings of emulators other than Ootake. Because of this, it is not uncommon to see reviews claiming that the PC Engine version has "bad colors." One review written in the early 2000s had a particularly strong influence. For a time, people hostile toward the PC Engine would repeatedly link to that article on a major Japanese anonymous online forum and use it to disparage the PCE version of Fantasy Zone. The problem was that the review relied on emulator screenshots that did not reproduce real‑hardware colors, declaring that "the colors are wrong," and then listened to heavily degraded emulator audio and concluded that "the sound is terrible." In reality, both judgments were based on inaccurate reproduction rather than the actual capabilities of the hardware. Looking back at reviews and user impressions from that era, there were no complaints about the colors at all. The screenshots printed in manuals and magazines consistently showed a clean and attractive-looking Fantasy Zone. As for the sound, it is true that people occasionally mentioned being disappointed that the whistle in Stage 1 was missing. However, many players also appreciated the strengths of the other stage themes, and at the time there were no widespread criticisms or reviews harshly attacking the audio. It is unfortunate that, years later, some people began repeating negative claims without verifying the facts, simply echoing what they saw online. This kind of uncritical bandwagon criticism can easily lead to unfair evaluations taking root. On the other hand, here is a review from 2020 of the PC Engine mini, published by GAME Watch. "PC Engine mini: Full Title Review – Fantasy Zone" (GAME Watch) In it, the reviewer writes: - "The colors are slightly different, but the screen layout is almost identical to the arcade version." - "It doesn't come across in screenshots, but the BGM feels a bit underwhelming." While reviewing Fantasy Zone as it appears on the PC Engine mini, the author also reflects on the original PCE version: "At the very least, to me at the time, the image on my home TV looked almost the same as the arcade version." The difference lies only in the color reproduction of the PC Engine mini, not in the reviewer's original memory. Their impression from back then was not mistaken at all. As for the sound, the PC Engine mini unfortunately has several inaccuracies in its audio reproduction—for example, the noise‑based drums can be overly sharp and distracting. In Fantasy Zone, these issues stand out even more, to the point that the mini fails to convey the simple, charming sound of the original PCE version. To help clear up these misunderstandings, I hope to share audio samples from Ootake or real hardware on X when the opportunity arises. Other titles that feel visually off unless played on real hardware or Ootake include games like "Gradius" and "Dungeon Explorer." On most general-purpose emulators, these games appear extremely dark, with colors that look dull and washed out. ↓Ootake default display. The overall look is close to the familiar video output    of real hardware.    Although darker than many other games, it is not excessively dark and    actually creates a nice atmosphere. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Default Source: "Gradius" (© Konami Digital Entertainment） ↓Ootake set to a configuration similar to many other emulators.    The overall image looks darker.    The player ship's gray, as well as ground enemies and items, all appear     somewhat dull. Note: Colors may appear different in some PC browsers.          For accurate color reproduction, please save the image and view it in Paint. Ootake setting: Gamma 0.94 , Brightness +30 , Non-Scanlined Source: "Gradius" (© Konami Digital Entertainment） In many other games as well — such as the Ys, Tengai Makyo, Valis, and Cosmic Fantasy series — comparing elements like skin tones and the smoothness of sky gradients reveals color differences that are too significant to ignore. In the next chapter, I will explain how Ootake reproduces the colors of the Japanese PC Engine — the colors originally intended by the designers.

How to Reproduce the Colors of the Japanese PC Engine
— the Colors Intended by Its Original Designers

So then, how can we bring the colors closer to those of real hardware? Around five years ago, an overseas enthusiast succeeded in extracting and digitizing the correction values used when converting the PC Engine's internal RGB signals into composite or RF video output. Displaying an emulator's screen using raw RGB data alone is less accurate than applying these correction values. With the correction applied, the resulting image indeed becomes much closer to the look of a real Japanese PC Engine — as well as to Ootake's color reproduction. However, even with these correction values applied, the result still differs somewhat from "the final colors." This is because, on real hardware, the correction values are followed by an additional conversion into analog video signals. After that, the signal passes through the television's own brightness‑adjustment circuitry before finally appearing on the screen. In contrast, Ootake has focused on reproducing "the final colors" from the very beginning — ever since its earliest version released twenty years ago. More concretely, Ootake is built on the following principles: - Never place colors arbitrarily; always preserve the overall balance. - Ensure that color adjustments do not break games that are particularly sensitive to color tone, such as "Fantasy Zone", "Gradius", or "Dungeon Explorer". - Compare the output against real hardware as closely as possible, adjusting until the overall atmosphere feels right. - Televisions of that era had lower contrast than modern digital displays, partly to prevent dark scenes in movies or video content from becoming completely black. As a result, darker areas tended to appear somewhat brighter compared to today's TVs. - Because early televisions varied widely in their factory calibration, with significant unit‑to‑unit differences in color tone, it is impossible to define a single "correct" color. This is something that must be kept firmly in mind from the start. Based on these principles, the actual implementation followed the guidelines below: - Use sRGB as the foundation for the overall color balance. - Adjust the gamma curve to prevent dark areas from sinking too deeply, aiming for a look that is both close to real hardware and easy to view. - Do not rely on a single hardware‑and‑TV combination; instead, verify the results across multiple real setups. * I also frequently visited retro game shops to study the colors on their in‑store demo TVs. Through this kind of repeated trial and error, I gradually refined the implementation. The default settings used by most players are chosen with great care, so that the intentions of the original creators are faithfully conveyed to the player. Because televisions of that era varied so widely from unit to unit, Ootake also allows users to make their own adjustments — within a range that does not break the overall color balance — using the "Gamma" and "Brightness" menus.

　
To Preserve the Appeal of These Classics for Future Generations

If the person who wrote that heavily misunderstood review of the PCE version of "Fantasy Zone" had been using an emulator with accurate color and audio reproduction, the article likely would never have turned out the way it did. When PC Engine emulators first appeared, simply seeing those nostalgic games running on a PC screen was enough to excite and move me. However, as emulators became more widespread, I realized that low‑accuracy reproduction carried the risk of causing these games to be unfairly judged. That realization became the single biggest reason I decided to release Ootake. I wanted to make it available as an emulator that could faithfully convey the strengths of the original works. One thing I personally try to be very careful about is that digital measurements, if taken in the wrong way, can easily lead to incorrect implementations. For that reason, I believe the best approach is to verify reality through analog observation and use digital data only as supporting evidence. Since the ultimate goal is for the emulator's output to match that of real hardware, the most reliable method is simply to place the two screens side by side and compare them directly. If any differences appear, I revisit the data — and then confirm the results again through analog observation. Without this cycle of repetition, a highly accurate emulator cannot be achieved. It isn't an easy task, but with the hope that these classics will continue to be enjoyed in their true form, I will keep refining Ootake.

2026.2.6 Written by Kitao Nakamura.



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