Re: Which Macs work with the AppleColor IIgs monitor?

[Paul Pietromonaco <paulp@netmanage.com>]

Sheldon Simms wrote:
> 
> In article <57anrb$qm8@darla.visi.com>, nathan@visi.com (Nathan Mates) wrote:
> 
> > In article <ZFJXptH.rocketusa@delphi.com>,
> > Darren Johnson  26 yo  32 MPG  <rocketusa@delphi.com> wrote:
> > >I'm thinking of getting a Mac, but would like to save on the monitor.
> > >I remember a thread a few mos. ago where some reported that dome Macs
> > >and not others worked with the AppleColor IIgs monitor. Anyone recall which.
> >
> >    I didn't think that any Macs could use the GS's monitor. The basic
> > problem is that the GS's monitor wants a 15Khz Horizontal Sync pulse,
> > while Macs want to put out at least a 30Khz pulse.
> 
> The only way a Mac can use the IIgs monitor is to generate interlaced
> output at the proper frequency. I have heard that some very old Mac cards
> could be programmed to do this, and AV Macs might possibly be programmed to
> do it, but Nathan is correct. In general, no Mac can use the IIgs monitor.
> 
> You wouldn't want to do it anyway. The dot-pitch of the IIgs monitor is
> lousy and Mac programs would look lousy on it. One of the reasons 640 mode
> dithering works on the IIgs is the poor output resolution of the IIgs monitor.
> If you use a second sight card this becomes immediately apparent since all
> sorts of colors that looked solid on the IIgs monitor suddenly become
> blocky checkerboards on the VGA monitor. Anyway, Mac programs designed for
> a high resolution monitor wouldn't look very good on the IIgs monitor.
> 
> You can get a pretty decent 14" SVGA monitor brand new for $250 and down
> that will work on current Mac models and whose output will be acceptable.
> 
> -Sheldon
> 
> --
> W. Sheldon Simms III - sheldon@atlcom.net


Hi everyone,
     Just to be thorough, I thought I'd relay my experiences using a IIgs monitor 
with a Macintosh.  You have to have the Macintosh Hi-Resolution Display video card 
- it's the card that Apple released after the original Macintosh II video card, 
and later replaced by the 4*8 and 8*24 boards.  It's a NU-BUS card *only* - so this 
means you basically have to use Macintosh II family machines.
     I found out about it when I first got my Macintosh IIcx.  I didn't get a monitor
with it, and I was desparate to see if it worked.  So, noticing that my IIgs monitor
had the same connector, I went for it.  It _did_ synchronize, and as Sheldon and Nathan 
surmised, the picture _was_ interlaced.  It defaults to the 512 by 384 (can't remember 
the exact numbers) display mode but you _can_ switch to the 640 by 480 display mode via 
the Monitors Control Panel.  The bad thing about this, however, is that the edges are 
then off your screen. (Later research in the Macintosh Tech notes indicated that, 
according to Apple, this was the only card that ever supported the IIgs monitor.)
     So, how did it look?  Terrible.  All fuzzy, and interlaced and, basically, yucky.
I immediately put the monitor back on my IIgs, and it looked great.  It's stayed there
ever since.
     Virtually yours,
     Paul

P.S.  As a side note, I've experimented with both the Macintosh II video card,
and the Macintosh Hi-Res Display card.   Besides supporting the Apple IIgs monitor,
the Mac Hi-Res Display card is also the first Macintosh video card that directly supports
SVGA monitors.  I discovered this when I was trying to connect a Macintosh II at work 
to an SVGA monitor.  I had to try about three different monitors before I could get one
to sync with it.  All of the monitors worked fine with the Hi-Res display card, and should
work with every Macintosh video card made ever since by Apple.  (Exceptions probably exist
- but that's the official party line, anyway).  So, if you find a used Macintosh II 
video card, and are thinking about adding that second monitor, be sure you try the 
combination first.  
 
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                               -paulp@netmanage.com

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