On 1 May 2017 at 15:38, Tom Brennan <[email protected]> wrote:
> Wow! All I can think of is some high voltage going on in there, like the > flyback transformer in an old tube TV. I never heard the one I worked on, > like you say probably because of all the machine noise in the tape room. I remember seeing an IBM article on how the 3290 was designed and built. A few years ago I had some reason to want to find it, and searched the IBM Systems Journal and Journal of R&D titles for the 1980s (when I know we got our first 3290), and was unable to find anything. I suppose it may have been a marketing glossy, but iirc it was far too detailed and technical for that. One piece of trivia I remember is that there are tiny spacers in the screen to keep the glass layers from bowing inwards under the vacuum; something that's needed only for a large and flat screen like this, and obviously not for other vacuum devices like CRTs which are made somewhat convex, or much smaller plasma displays. These spacers are visible, though not distracting. Maybe Dave could confirm my memory on this one by looking at the actual device for little short (iirc vertical) dark lines spaced evenly across the screen. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
