21 Jan
2018
21 Jan
'18
10:08 a.m.
On 1/21/18 12:04 PM, Paul Koning via cctalk wrote:
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
On Jan 20, 2018, at 11:06 PM, Ethan Dicks via
cctalk <cctalk at classiccmp.org> wrote:
On Sat, Jan 20, 2018 at 8:32 PM, Paul Anderson <useddec at gmail.com> wrote:
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 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.