On 1/21/18 12:04 PM, Paul Koning via cctalk wrote: > >> On Jan 20, 2018, at 11:06 PM, Ethan Dicks via cctalk <cctalk@classiccmp.org> >> wrote: >> >> On Sat, Jan 20, 2018 at 8:32 PM, Paul Anderson <used...@gmail.com> wrote: >>> I think just the VR12, VR14, and the VR17. >> OK. I've never had any of those. I'm more wondering what modern >> tubes might work. > Remember that the GT40 is a vector drawing display, not a raster scan. So > you need a tube and associated deflection machinery that can handle high > frequency X and Y deflection waveforms accurately. This is not easy, > especially with magnetic deflection. I don't know what DEC used; CDC did it > both ways with the 6000 series consoles. The original ones had "dual radar > tubes" with electrostatic deflection, hairy circuits with 3cx100a5 final > amplifier tubes. The next generation, in the 170 series, had a single large > tube with magnetic deflection but still random access vector drawing. How > they did that with magnetic deflection is not clear to me, it sounds hard. > > paul > > I'm sure it has been mentioned in past discussions on this topic, but a monochrome atari video game monitor would likely be relatively easy to use as a GT40 display.
--tom
