Good capture of a classic computer usually means an external scaler — a RetroTINK or a Framemeister sitting in the signal chain. Those are excellent devices. But for documenting Atari ST video I wanted something a scaler doesn’t really give you: the exact original pixel grid, reconstructed deliberately, with every scaling step under my control.
It turns out you can do that with just a capture card and some careful post-processing. This is the workflow I settled on, using an Atari Mega ST as the example — its native resolution is 320×200, but the same approach works for other classic machines.
For the card itself, see my notes on the Micomsoft SC-512N1-L/DVI.
The idea: do the scaler’s job in software
A scaler does three things: it samples the analogue signal, works out the active image area, and scales that cleanly to a modern resolution. Split those apart and you can do each one deliberately — the capture card samples, and software handles the framing and scaling, using only integer operations so the source pixels are never resampled or blurred.
The output is native-resolution, free of the softness and ringing an analogue chain introduces, and sized for a modern platform (1080p50 or 1080p60).
Hardware
- Atari Mega ST
- Atari ST RGB SCART cable (Retro Computer Shack)
- ArcadeForge Sync Strike — extracts clean sync from the ST’s RGB output
- Micomsoft SC-512N1-L/DVI capture card — samples low-resolution analogue video without forcing its own scaling or filtering
Software
Both free and well established:
- AmaRecTV Live — captures uncompressed video
- VirtualDub — does the deliberate, step-by-step scaling
The workflow
Raw analogue RGB to clean native-resolution output:
- Capture uncompressed in AmaRecTV at 288p50, 720 pixels per line sampled.
- Upscale to 1280×288 with Lanczos3 — more horizontal precision before cropping.
- Crop to 960×200 — isolates the active Atari ST display area.
- Divide width by 3 with Nearest Neighbour — restores the original 320×200 grid.
- Multiply width and height by 5 with Nearest Neighbour — 1600×1000, perfect integer scaling.
- Frame into 1920×1080 (1080p50) — no fractional scaling.
- Compress with H.264.
From step 4 on, everything is integer-only — no filtering or resampling touches the source pixels. Oversampling horizontally during capture (step 1) is what makes it possible to recover exact pixel boundaries later.
Example captures
Three clips produced with this workflow, embedded from unlisted uploads.
Atari ST GEM desktop
Good for judging line sharpness, font clarity, and pixel alignment.
Loom (Lucasfilm Games)
Dithered gradients and fine detail that benefit from clean sampling.
Xenon 2 (Bitmap Brothers)
High-contrast pixel art, fast scrolling, steady 50Hz motion — a good stress test.
Is it worth it over a scaler?
For live use or a multi-system setup, no — a scaler is the right tool. But if you’re capturing for archival or documentation, this gets you native-resolution ST video that’s sharp, accurate, and faithful to the hardware, with nothing in the chain making decisions you can’t see.
