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I'm Kitao Nakamura, the developer of the PC Engine emulator "Ootake."

This article is a follow‑up to my previous piece,
“Thinking Seriously About Pixel Aspect Ratios in Games.”

Last time, I focused mainly on the theory.
This time, I actually visited several game centers (arcades that still have CRT cabinets)
to see how each place is adjusting their screens in practice.

Within the range of locations I was able to visit:

Shops that opened in or after the 2000s generally used what I'll call the "MAME style,"
stretching the image to fill the entire 4:3 screen.

Long‑running arcades from the 1990s tended to favor "aspect‑ratio‑conscious"
adjustments, leaving black borders at the edges.

Let's take a closer look at how each of these approaches actually sets up the image.


The "Fill‑the‑4:3‑Screen" MAME Style Used
in Game Centers Opened After 2000

Since the year 2000—and especially by around 2005, when YouTube and Nico Nico Douga had just begun—videos of games played on MAME (an emulator for arcade PCBs) started circulating widely online. Because there are far more MAME‑captured videos than recordings from actual arcade boards, the MAME look gradually became the "standard" aspect ratio that many people came to assume was correct. The MAME style of screen adjustment ignores the black‑border information output by the original hardware and simply stretches the image to fill the entire 4:3 screen. At first glance, this full‑screen presentation feels pleasant because it uses every inch of the display. However, many games end up with distorted character proportions, meaning players are seeing something different from what the graphic designers originally intended. ↓When the aspect ratio is off, the difference in how the game feels    to play is far from small. In this scene, even the sense of being trapped    inside the frame dragon changes noticeably. Source：『Gradius: Origin Collection』（© Konami Digital Entertainment） ↓The "Covered Core"(the Stage 7 boss), with its cute, rice‑ball‑like appearance.    When the image is stretched to fill the entire 4:3 screen, only the vertical cover    becomes elongated, which looks unnatural.    While playing, the difference in how naturally it rotates becomes quite    noticeable. Source：『Gradius: Origin Collection』（© Konami Digital Entertainment） MAME‑style adjustments do have some advantages. - Staff can simply stretch the image to the edges of the screen without thinking too much about it, which reduces their workload. - Newer staff members can also learn this method quickly. For arcade operators, this contributes to lowering operational costs. But with this approach, the artwork that designers carefully crafted ends up being distorted. In the next section, I'll examine the black borders at the edges of the screen, which serve as a guiding aid for the designers' intentions.

Black Borders: The Unsung Heroes That Keep Characters From Distorting

Even in shops that adjust most of their cabinets using the MAME style, there were a few exceptional cases where certain games were set up with proper black‑border adjustments. ↓One of those exceptions was this cabinet running Star Force.    If you stretch this game to fill the entire 3:4 (vertical) screen, the image    becomes obviously too tall, and the staff likely noticed this.    So instead of forcing the upper black border to disappear, they adjusted it    to the correct aspect ratio—making the test grid pattern a perfect square. Source：『Star Force』 (©Tehkan)　Click the image to view a larger version. I've seen people on social media and message boards insist, quite firmly, that "there were never any black borders — filling the entire 4:3 screen was the correct look." However, as the photos above show, multiple arcades did in fact use black borders. Because the area from the edge of the CRT to the bezel appears as one continuous shade of black, players using arcade cabinets would almost never notice whether black borders were present or not. That's why many people simply don't remember them and confidently claim, "There were no black borders." (But in this situation, asserting that one remembers the absence of black borders is, realistically, a very difficult claim to support. As you can see, black borders did in fact exist. In the 1980s in particular, CRT performance was far inferior to what we have today, and the edges of the screen were prone to distortion. For that reason, most arcade PCBs avoided using the outermost areas of the display and left them as black borders. - Technically, the hardware could output 320 horizontal dots → but because the edges distorted, only 288 dots were used as the actual display area. - Technically, it could output 240 vertical dots → but due to edge distortion, only 224 dots were used. This is why so many 1980s arcade games list resolutions such as 320×224, 288×224, or 256×224 in their specifications In cafés and candy shops, frequent screen adjustments weren't practical, so it's reasonable to assume they avoided stretching the image all the way to the edges and instead left some black borders intact. (because the visible display area of a CRT can shift significantly during transport or over time) In the next chapter, I'll examine why instruction manuals for arcade PCBs rarely included detailed, step‑by‑step guidance on how to fine‑tune CRT adjustments.

　
Aspect Ratio Adjustment: The Unspoken Rule That Circles Stay Circles
and Squares Stay Squares

CRT televisions used a test pattern called a monoscope pattern to adjust the aspect ratio (the vertical‑to‑horizontal proportions). Broadcast stations also displayed these test patterns during early‑morning off‑air hours. ↓An example of a classic monoscope pattern, composed of elements such as    perfect circles and square grid cells. By carefully watching the screen and turning the adjustment knobs until the circles appeared perfectly round and the grid cells perfectly square, you could set the display to the correct aspect ratio. There were arcade PCBs at the time that displayed circular or grid‑based adjustment patterns during startup, and many games offered a crosshatch grid in their test mode for screen calibration. ↓"Strikers 1945 II" by Psikyo    A message instructs the operator to adjust the screen until the circle appears    perfectly round. Source：『Strikers 1945 II』 (© Psikyo) ↓Grid pattern from "Xevious".    There likely wasn’t enough memory available to display a circle.    When this grid is adjusted so that each cell is a perfect square, in‑game    graphics appear undistorted — the PCB’s output was square‑pixel to begin with. Source：『Windows 95/98 version of Xevious (publisher: MediaKite)』（© Bandai Namco Entertainment Inc.） Aside from Psikyo's games, which use a circular pattern for alignment, it seems that no arcade PCB manuals provided detailed instructions on how to adjust the aspect ratio. In the materials I've reviewed, I haven't found any manuals that give concrete directions such as "match this to a perfect square" or "stretch the image to the screen edges." After searching through various sources, I finally found one example that comes close: a Sony CRT television manual that includes a relevant description. ↓Instruction manual for Sony's "WEGA" CRT televisions    The section on vertical and horizontal size controls explicitly shows a diagram    instructing the user to correct an ellipse into a perfect circle. Source：『WEGA Instruction Manual』 (© SONY) From what I've seen, instruction manuals for other televisions simply state "correct any distortion," without explaining the specific method of adjustment. The phrase "correct distortion" also includes correcting vertical‑to‑horizontal stretching—that is, adjusting the aspect ratio. Because ensuring that circles appear as circles and squares as squares has long been an unspoken standard practice in television imaging, manufacturers likely felt no need to spell out the procedure in detail. As I wrote in the previous article, there is one exception: the grid pattern on Capcom's CPS hardware. Even if you adjust it so that each cell appears perfectly square, the aspect ratio still does not match. I plan to cover the details of this in a separate article at a later time.

To Preserve the Appeal of These Classics for Future Generations

Both then and now, the way arcade cabinets are adjusted varies from place to place, and each game center sets its own standards at its discretion. For example, with the original "Ghosts'n Goblins", I sometimes see machines in modern arcades where Arthur has become noticeably wider than intended. The Arthur I remember from table‑type cabinets and candy shops back in the day was definitely slimmer. When I come across a distorted "Gradius II" or "Ghosts'n Goblins", I can’t help feeling that it's a shame—the designs lose their intended form. I also suspect that revenue might even improve if the aspect ratio were adjusted correctly; a properly proportioned demo screen would likely encourage more people to drop in a 100‑yen coin. Many modern re‑releases on contemporary game consoles also seem to rely too heavily on MAME as a reference. YouTube is filled with arcade‑game footage that has been stretched to fill a 4:3 frame. For works that designers crafted with such care, this is far from an ideal situation. If the gaming world approached aspect‑ratio decisions with the same seriousness seen in television, film, or manga, I believe the culture of games could become something even more beautiful than it is today. There was, however, one encouraging sign. Among owners of original PCBs—particularly for titles like the Gradius series—most did not stretch the image to fill the entire 4:3 frame. Instead, they played using what appears to be the aspect ratio intended by the designers. - You can find examples of this by searching video sites for terms such as   "GradiusII PCB." 　YouTube検索：「GradiusII PCB」　YouTube検索：「グラディウスII　基板」 Although this article contains several remarks about the 4:3 display behavior seen in MAME, none of them are meant as criticism of MAME itself. MAME is, needless to say, an outstanding emulator. The aspect‑ratio issue has been discussed repeatedly—especially overseas—so I look forward to seeing how it may continue to improve in the future. There was a time when "video games" were often looked down upon, and even today that sentiment lingers in some places. But I believe games are a wonderful cultural medium—one that deserves to be preserved and passed down properly, just like film or manga. I intend to continue examining this aspect‑ratio issue with sincerity. If I can gather more conclusive evidence and broader support, I would be glad to share the findings with developers and arcade operators as well.

2026.3.21 Written by Kitao Nakamura.


The previous article
Please also see "Thinking Seriously About Pixel Aspect Ratios in Games."
In that article, I discuss the evidence showing that many arcade PCBs output square‑pixel signals,
as well as methods for calculating pixel aspect ratios.


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