[comp.sys.atari.st] Standing Waves

fred@pnet01.cts.com (Fred Brooks) (05/23/88)

tran@orion.arc.nasa.gov (Andy-Cuong Tran) writes:
>I have a 1040ST.  I notice that whenever I LOAD up a file from the internal
>disk drive or from a ramdisk, diagonal standing waves would appear on my
>Atari SC1224 RGB monitor for a few seconds and then disappear.  Is this the
>norm?  Can this be fixed?  I also notice that certain program causes other
>interference to appear on my monitor.  Whenever I use Dcformat, for example,
>to format diskettes, horizontal standing waves would be visible on the screen
>during the process but would disappear afterwords.  Any comments on the 
>subject matter will be gratefully accepted.  Thank you.


I believe it's caused by the IPL being set to 7 for long periods of time
and not being in sync with H blanking. It looks like something in the video
is not being updated during this time causing the lines. This is just a
guess.

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