Extremely CISC instructions

Tony Duell ard.p850ug1 at gmail.com
Wed Aug 25 22:41:13 CDT 2021

On Wed, Aug 25, 2021 at 7:47 PM Paul Koning <paulkoning at comcast.net> wrote:
> > On Aug 25, 2021, at 2:21 PM, Tony Duell via cctalk <cctalk at classiccmp.org> wrote:
> >
> > On Wed, Aug 25, 2021 at 7:17 PM Patrick Finnegan via cctalk
> > <cctalk at classiccmp.org> wrote:
> >>
> >> Landscape monitors work fine as portrait for me when I turn them on their
> >> side.
> >
> > You may have problems converging a colour CRT, particularly an in-line
> > gun type, if you do that. They are designed for the earth's magnetic
> > field to come in a particular direction.
> No they aren't.  If that were true they would mess up if you turn them (horizontally) 90 degrees, or move from Canada to Equador.

With a delta gun tube, you most definitely mess up the convergence if
you turn the monitor around. Colour TVs/monitors using such CRTs had
to be set up in the position they were to be used.

With an in-line gun tube, the thing that really matters is the
vertical component of the earth's magnetic field. This does not change
if you turn the set round. That was one great advantage of such CRTs .
If you tip it on its side then the horizontal  component becomes the
important one. Which firstly will be different to the vertical
component and secondly will change when you turn the monitor round.

And yes there were CRTs set up at the factory for the northern and
southern hemispheres. I remember Bang and Olufsen made a TV where the
CRT was effectively mounted upside-down (so that the EHT connector was
far enough from the cabinet to meet safety requirements) and the CRT
had to be the one for the 'wrong' hemisphere as a result.


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