On Fri, May 20, 2022 at 9:23 AM William Levak <wlevak_at_sdf.org> wrote: > > > The original PET monitor was a standard white monochrome picture tube. it indeed was a "P4" B&W CRT, unfortunately, P4 phosphors were made in at least 5 different formulas, each having different "secondary" phosphorescence. The most common P4 in the '70s would glow a bit bluish at increased brightness levels. I have recently completed a home made vector monitor with a 11" standard P4 CRT from a 1971 BW TV, I use it with an Atari Asteroids arcade PCB. Most of the traces look white, but the shots look definitely blue as in that case the brightness is increased. > The exact shade of white depended on the manufacturer. Viewing pictures correct > on a current color monitor is subject to all the effects caused by viewing > an analog image on a digital monitor. Analog monochrome monitors have a > continuos layer of phosphor. Digital color monitors have triplets of color, > spaced regularly on the surface. A common effect is fringing (edges of > letters come out as a different color because the width of letters are not > integer multiples of the color triplets). Another effect causes the > letters to be irregular in shape. This comes from the fact that the image > must be scaled to fit a different resolution monitor. In the scaling > process causes some lines of image are dropped because of rounding > errors. correct. > > On Thu, 19 May 2022, Rhialto wrote: > > > Do we know which colour the original (pre-green) PET monitors had? From > > memory I'd call it blue-ish white. > > > > You can see it on various YouTP9y_7it3ZMube videos (such as > > https://www.youtube.com/watch?v=eP9y_7it3ZM at around 7:20), but I > > wouldn't trust the colour balance on youtube videos too much. > > > > At a guess it would be somewhere near r/g/b/ AA/AA/FF, but can we get > > more precise? > > > > -Olaf. > > -- > > ___ "Buying carbon credits is a bit like a serial killer paying someone else to > > \X/ have kids to make his activity cost neutral." -The BOFH falu.nl_at_rhialto > > > > wlevak_at_sdf.org > SDF Public Access UNIX System - http://sdf.org >Received on 2022-05-20 10:03:06
Archive generated by hypermail 2.3.0.