Re: help, RGB

[madsci@tribeca.ios.com (Erick Dietrich)]

In article <51nc0f$aep@darla.visi.com>, nathan@visi.com (Nathan Mates) wrote:

> In article <Pine.SUN.3.91.960916191758.10195B-100000@lo-pan>,
> Cyrus Roton  <croton@ridgecrest.ca.us> wrote:
> >There used to be a device, called "Mappler", which converted Apple analog 
> >RGB (15-pin) to IBM digital RGB (9-pin). There seems to be plenty of 
> >cards to output Apple RGB and plenty of IBM type monitors at low prices. 
> >But how to interface the two???  Does anyone have info on this subject?
> 
>    An Apple II is not a Macintosh, especially when it comes to RGB
> video out. Sure, the connectors are the same size, and both say
> they're for Apple analog RGB monitors. But, the GS and most Apple II
> RGB cards put out a horizontal sync signal of 15Khz. Pretty much all
> modern Mac and PC RGB monitors require at least a 30Khz horizontal
> sync signal.

Just for the record, I was told by several techies that a multisync
monitor will not work from a IIgs RGB port.  However, I have tried a NEC
MultiSync 3D and 2A model monitors, as well as  my father's brand new HP
multisync and they have all worked.  

You might be able to find an older NEC MultiSync.  I think I saw Alltech
was selling them.  Funny, they're one of the places I called, and they
said it couldn't be done!

My current setup connects my IIgs to a VGA switchbox with a regular IIgs
RGB video cable with one of those adapters that comes with new Apple
multisync monitors, the one thats the opposite of the Mac-to-VGA adapter. 
My Quadra is connected to the other side of the switch, and my MultiSync
3D can be shared on the fly.  The only problem is that the IIgs screen is
off center a bit.

The video quality is very good, better than with my IIgs RGB monitor.  And
I only have one monitor on my desk.

I recently got an Apple IIe RGB card, the Aux slot one.  I don't have the
connector for it, the one that would take the header and give me a real
video port.  Does anyone have one?  

Also, will that card, or an Apple IIc's RGB port work with the IIgs's monitor?

>    Also, I think that only the CGA/EGA monitors on PCs had 9-pin
> digital connectors. SVGA is definitely 15-pin analog. (But, that's a
> different 15-pin setup: 3 rows of pins vs 2 for Apples)

Right.

>    Thus, a straightforward Mac RGB -> [S]VGA converter won't work
> when connected to an Apple II.

You might have some luck with a more expensive (around $40) adapter that
has a bunch of switches.  Then again, you might burn something out. 
Proceed with caution.

BTW- Does anyone know anything about connecting ANY Apple II to a
Commodore 2002 monitor?  Its got composite inputs, and a 9 pin male RGB
port.  Switch on the back allows you to set it to Digital Positive,
Digital Negative and Analog signals.  I've used it as an EGA and a Tandy
16 Color monitor in Digital mode.

-Erick