Re: Problem Using a Commodore 1084s Monitor on a IIgs

[heuser.marcus@freenet.de]

On Jan 21, 11:23 pm, Polymorph <polymorp...@hotmail.com> wrote:
> On Jan 22, 4:51 am, heuser.mar...@freenet.de wrote:
>
> > Via composite or via RGB?
>
> Via composite only.

So you know that the monitor generally works but it won't
help you with the RGB connector. I asked, because in
Germany a lot of DVD players are connected via RGB
(Euroscart) because of the much better picture quality.


> There is apparently many different connections available
> for the 1084 monitors and unfortunately mine does not have
> the SCART adapter. I wish it did as I already own a IIgs -->
> SCART adapter from Vintageware. The 1084 monitor I have
> only has the D-9 RGB connector + the usual composite sockets.

But the inner workings on the signals should be very similar
for the analog RGB input - maybe somebody can get you the
schematics of your exact monitor.

> > Pin 3 ("composite sync") of the GS video output jack must be
> > fed into the composite video input of the Euroscart connector
> > (pin 20).
>
> Well, as per the Apple II FAQ, I have the composite synch
> wired up to the composite synch of the D-9 connector (from
> memory I think its pin 7).

Here's another possibility (though unlikely:

A defective connector jack with a broken pin.
I once had trouble with this 19 year old monitor and had to
resolder the composite connector pins because the solder
point on the printed board was defective.


> > I would try to connect pin 3 of the GS output to the composite
> > input of your monitor.
>
> Yep, did that. That is as per the Apple II FAQ.

So pin 7 on the monitor is not only the sync signal but also
a full composite input? This is the way the Euroscart models
work internally.

> Any comments on the usage of a 75 Ohm resistor between composite synch
> and ground?

Not necessary with the Euroscart models so I can't really
comment on that.

> I think I will try this anyway, as Jeff Blakeney has a
> pretty good rep around the traps and I'm sure he wouldn't have said
> that if it were'nt necessary for him.   :-)

I don't know if this works but I don't see that it could break
anything.

bye
Marcus