Re: My Apple IIGS is back

["Michael J. Mahon" <mjmahon@aol.com>]

limtc wrote:
> Actually the issues is a little more serious than this. I tested it on
> 2 TV for ROM 1:
> 
> - on one TV, it always shown in monochrome text (like ROM 3)
> - on another TV, it is like what I described (most of the time it
> shows NTSC artifacts)
> 
> Both works fine for ROM 3.

That result is completely consistent with the hypothesis that
the ROM 01 is "leaking" low levels of color burst that are enough
to keep the more sensitive monitor always in color mode.

The first thing I'd try is to use the longest video cable you
have between the ROM 01 and the more sensitive monitor.  If you
don't have a cable longer than 6 feet, try an *audio* cable.

The object is to increase the high-frequency attenuation of the
cable to reduce the level of the 3.58MHz burst somewhat, which
may be enough to fix the problem.

If it does not fix the problem, a simple circuit may need to
be constructed to remedy the problem...

> And for my ROM 1, after some use, the red color will kind of
> disappeared. And sometimes it will starts up without red colors.

That sounds like something different.

> On 4锟斤拷20锟斤拷, 锟斤拷锟斤拷3时43锟斤拷, "Michael J. Mahon" <mjma...@aol.com> wrote:
> 
> 
>>A very simple but possibly annoying workaround would be
>>to unplug the video from the monitor (or IIgs) for a few
>>seconds, then re-plug it.
>>
>>(BTW, if that doesn't return the monitor to monochrome mode,
>>then there may be some other problem.)
> 
> 


-- 

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

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