The Hall SC-VGA-2 video processor, the Atari ST and NeXTSTEP: more tales of the unscreenshotable
This is the Hall Research Technologies SC-VGA-2, sold as a VGA/HDTV Video Processor." In addition to slicing, dicing and pureeing, apparently, it will take any of a bundle of input formats and both rescale and resample them on the fly into the VGA or HDTV signal you desire, including 60Hz rates. This came from a seller specializing in teleprompter equipment and Hall still sellsan HDMI versionwith additional resolutions ... for around US$500. However, this or the slightly newerSC-VGA-2AandSC-VGA-2Bare all relatively common devices and found substantially cheaper used. Let's try it out and show some sample output, including those delicious NeXTSTEP system messages and some ST grabs.
Cameron Kaiser
With the obscurity of some of the hardware Cameron Kaiser details on his website, I'm not surprised he has some seriously unique needs when it comes to taking screengrabs. He couldn't very well not take the device apart, and inside it appears to be a system with two small processors, at least one of which is an Intel 8051 8bit microcontroller. Kaiser goes into his usual great detail explaining and showing how the device works.
If you've got unique screengrabbing needs, this might be of interest to you.