Tony Duell ard at
Fri Feb 3 12:41:57 CST 2006

> > All you really had to do to fry the MDA on a PC was to program the
> > horizontal frequency a few KHz too high.
> I thought what killed it was setting the horizontal frequency to zero.

No, the horizontal drive in the 5151 monitor is at least AC coupled (by 
the line driver transformer if nothing else), so a constant high or low 
on the horizotnal pin of the DE9 connecotr does no damage at all.


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