Re: RGB to VGA on a IIGS (again)

[nyder <nyder.23@gmail.com>]

Michael J. Mahon wrote:
> nyder wrote:
> > Intersil makes a bunch of different chips that are great for this.
> > I've been working on a converter for old computers (and other devices)
> > that takes the various res's and syncs it to a n RGB type monitor,
> > with an option to adjust the sync for multisync monitors.
> >
> > Then intersil came out with a chip that will do the same thing, but
> > convert it to Componet form, which I realised is probably better for
> > todays TV's.
>
> Although upsampling is necessary for VGA display, it may not be
> necessary for a well-designed 480i display mode.  Interfacing a IIgs
> to a 480i component input would only require a few video op-amps
> to matrix the RGB input into YCrCb.
>
> Certainly, the simpler analog approach should be tried first.
>

Cool, I figured the lowest mode was probably good for things, but I
wasn't able to test anything out.


> > I recently picked up an LCD screen for a Xbox 360 (I don't have one)
> > because it has componet vid in.  Granted it's only a 9.2" monitor, but
> > it gives me a componet viewing source to experiment on.
> >
> > I have a GS, but no monitor for it.  I did pick up some older mac
> > monitors, but i'm not sure they will work.  But very few of my old
> > computers actually have the monitors for them.
>
> Unfortunately, no Mac monitors will work with the IIgs.  The IIgs
> monitor is an analog RGB monitor with NTSC(-like) scan rates.
>
Okay, I wasn't sure about this.  I know some of the mac modes is
stupid crazy (in my opinion), but I hadn't taken the time to check the
specs of the GS's vid out.
I have about 4 various commodore monitors (15khz, rgb), plus just 1
multiscan (15kHz-35kHz, Sony cpd-1302)

One of the chips I got from Intersil will take any sync and supposedly
smooth it out so it works, but I haven't tested it yet.  I need to
learn how to use my Oscilloscope a bit better first, though maybe I
can just take the readings my with multimeter.  Not that it would help
on a Mac monitor, but it should help for older mac computers
connecting to some sort of rgb monitor.


> > anyways, i'm hoping to get back to my electronics work soon, so if you
> > let me know what the monitor is you want to hook your GS up to, i'll
> > see about making a device for you to test for me (and then keep a
> > working version for the testing, of course).
> >
> > Plus any input onto what sort of monitors people are trying to connect
> > their older computers too would be nice.  If everyone is going
> > componet then that makes things easier.
>
> Unfortunately, the future of the component interface is also in doubt.
> It is viewed as inconvenient by casual users and insecure by content
> providers.  However, it has a bit of "legacy" inertia, so it may remain
> common on new monitors for a few years.  Ultimately, it will be replaced
> by HDMI or one of its derivatives for a hard-wired interface, and by
> one of the contenders for the "standard" wireless HD interface.
>
>
Ya, I guess thats very much true.  But knowing the market, i'm not
going to hold my breath, plus i know I will be making devices to get
around it, since the market will want them.  (at least, unless they
figure out some good protection, which i'm not holding my breath on).

While I still have access to some decent rgb monitors (thanks to
commodore), even these are getting hard to find.  I love collecting
old computer/video equipment, but they have to work before I put them
in storage.  What I really want to do is run a "hands on" museum of
older computer & vid consoles.   Which is why I have to make sure
everything I collect works.

This is such a pain sometimes.  I mean, we have a million stupid ways
of doing crap, history has shown that not going with a standard
usually leads to a fragmented market, unless something becomes the
dominate force for whatever reason (like VCR vs Beta).

I can go pick up LCD's for $10 because they have stupid ass
propriatory interfaces, so they are basicly useless.  How many
different USB plug types do we need?  Firewire plug types?

oh, well, guess we all could bitch about the stupid corps forever.  If
they weren't so concerned about squeezing whatever they could from us,
we would of already had a standard done and the next gen (bluray, HD)
would already be a standard.
Of course, we would also have the fat internet bandwidth now if
companies kept their promises.

oops, I went into rant mode, guess I'm done here.  =)





> > On Jun 26, 12:46 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
> >
> >>mdj wrote:
>
> >>>I think this problem will plague us indefinitely until either somebody
> >>>designs a custom solution, or physical display resolution becomes so
> >>>damn high than the effects disappear into the 'noise'
> >>
> >>Right.  "Smart" upsampling to 1080p should do pretty well.  I haven't
> >>tried that yet...
>
> -michael
>
> NadaNet file server for Apple II computers!
> Home page:  http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it's seriously underused."