Atari ST colour modes (Low-Res and Medium-Res) run at a horizontal scan frequency of 15kHz, a frequency almost no modern VGA monitor supports, since anything made in the last two decades expects at least 30kHz. High-Res monochrome runs at roughly 35kHz and gets along fine with most displays, but colour gaming is a different story entirely. A few older premium panels are the notable exceptions, and the NEC MultiSync LCD1970NXp is the best known of them.
Panel Technology Matters More Than You'd Think
- MVA/PVA panels, the surprise winners. Their flexible crystal alignment tolerates unusual 15kHz signals far better than standard panels. The classic example is the NEC MultiSync LCD1970NXp, a 19-inch premium panel from around 2005 that genuinely handles 15kHz. Most LCDs only accept analogue VGA from 31kHz up, but this one is one of the rare exceptions, letting you connect an Amiga 500/1200, Atari ST or arcade board directly over a VGA cable without an upscaler. Its high-quality panel also gives wide 176-degree viewing angles and a strong 800:1 contrast, and it handles Medium-Res colour reliably once you fine-tune the H.Size setting. It's the monitor that runs my MiST and MiSTer.
- IPS panels, a mixed bag. Some work (a widescreen Lenovo ThinkVision LT1952p reportedly fills the screen beautifully via an ST2VGA adapter), others don't, and there's no way to tell without testing.
- VA panels, a genuine hidden gem. The Dell SE2722HX 27 (identical to the SE2722H) officially lists its horizontal range as starting at 30kHz, but its video scaler actually handles unlisted 15kHz support, something the community discovered through testing. Because it has a VGA input, it takes the raw RGB signal of old computers and upscales it to its native Full-HD 1920×1080, letting you connect an Amiga, Atari ST or arcade board directly without an OSSC or RetroTINK. Its VA panel gives a strong 3000:1 contrast for deep blacks, and it separates PAL and NTSC signals cleanly for smooth scrolling. It drives my Atari Mega ST 4 "Low" at 15kHz. The trade-offs: no built-in speakers, you have to switch the OSD aspect ratio to 4:3 (it's a 16:9 widescreen panel), and a heavily upscaled analogue signal can show faint vertical jailbars, which most retro fans accept given the price.
- The universal fix, an Open Source Scan Converter (OSSC) upsamples the 15kHz signal for any HDMI monitor, at the cost of extra hardware and money.
If you're chasing 15kHz authenticity, buy the specific panel model people have already confirmed working in the forums, don't trust a spec sheet that just says "supports VGA."