indridi@rhi.hi.is (Indridi Bjornsson) (03/02/90)
Hi there.
A friend of mine, who is working in a powerstation
has a problem with his computer. Currently he is using
Ericson computer (with Display monitor unit 3111 and
Monochrome graphics board 1070) and wants to get a new
computer. The thing is that no monitor he has tried other
than the old one seems to work properly. They are all
"wavie" ( i.e. the picture seems to float on the display).
It would not be so bad if one could buy them to day, but
you can't.
My friend has a theory: The vertical tracing on the
Ericson display is 50Hz, but all the others aren't.
So, I wonder are there anybody out there who have had
similar problem (and found a solution) or have a clue on
how to solve it or do you know of other terminals that
have 50Hz vertical tracing.
---
Indridi Bjornsson
Ljosheimum 18A, 4h. Internet: indridi@rhi.hi.is
104 Reykjavik. UUCP: ..!mcvax!hafro!rhi!indridi
ICELAND University of Iceland.
------------------------------------------------------------------------------jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (03/03/90)
In article <1553@krafla.rhi.hi.is> indridi@rhi.hi.is (Indridi Bjornsson) writes: > A friend of mine, who is working in a powerstation >has a problem with his computer. Currently he is using >Ericson computer (with Display monitor unit 3111 and >Monochrome graphics board 1070) and wants to get a new >computer. The thing is that no monitor he has tried other >than the old one seems to work properly. They are all >"wavie" ( i.e. the picture seems to float on the display). >It would not be so bad if one could buy them to day, but >you can't. > My friend has a theory: The vertical tracing on the >Ericson display is 50Hz, but all the others aren't. > > So, I wonder are there anybody out there who have had >similar problem (and found a solution) or have a clue on >how to solve it or do you know of other terminals that >have 50Hz vertical tracing. My monitor is sitting on my desk which is apparently about 1 meter from the conduit in the wall where the electrical power comes into our building. Sometimes the picture moves and flickers in a wavy motion. I believe that the magnetic fields around the electrical conduit are causing my problem. Different video modes operate at different vertical sweep rates, some of which will cause beat interference patters with the 50 Hz (60 Hz in North Amer) power line frequency when there are magnetic fields in the vicinity of the monitor. Probably some monitors are more sensitive than others to magnetic fields. Maybe you should arrange to test a variety of different monitors in your power station, to see if any are satisfactory. Also, the physical position of the monitor in relation to magnetic fields would make a difference. Perhaps it is possible to move it to a better location. -- John Dudeck "You want to read the code closely..." jdudeck@Polyslo.CalPoly.Edu -- C. Staley, in OS course, teaching ESL: 62013975 Tel: 805-545-9549 Tanenbaum's MINIX operating system.