New monitors on old machines

[Tony Duell]

> 
> --- Julian Wolfe <fireflyst at earthlink.net> wrote:
> 
> > No really, just buy a $100 scanconverter. It's not
> > worth the hassle.  What's
> > your time worth?
> 
>  There is the merit of learning how to do something.
> No, I for one can't blow a c-note everyday on whatever
> I feel like either.

I will agree with both of those comments.

> 
> > > Well, I wonder what the chances are that an LCD
> > monitor would 
> > > work with CGA inputs (dropped down to the proper
> > voltage 
> > > levels).  The question gets back to the sync
> > issue.  But it 
> > > would not surprise me if some of them might not
> > actually have 
> > > been designed to accept NTSC TV scan rates.

The Maplin catalogue (Maplin is a high-street electronics shop in the UK) 
lists a PAL decoder that takes in UK TV PAL video (if you see what I 
mean) and outputs analogue RGB and sync on a DE15 connector. The 
catalogue description claims that most LCD panels and projectors will 
sync to that. Not having got such a display I can't comment further.

>  If some of these things had a seperate "video" input,
> I can see them accepting 15.75khz. But if we're
> talking about the 15 pin connection, what would be the
> reason for constructing the thing to take it there?


I recently used an video projector. It had a RCA video input (which could 
take PAL, NTSC, SECAM (I think), etc). A S-video socket. And a DE15. The 
last was both for VGA inputs _and_ for aanlogue RGB at TV (15.x kHxx 
horizontal) rates.

It wouldn't suprise me if other devices were similar in this respect/

>  And it occurred to me, some of these modern
> multisyncs, though probably a long shot, might wind up
> being able to accept 26.4khz. There's nothing saying
> they'd automatically crap the bed as soon as it sees
> 31.499999999khz. But like I said, if any did, they'd
> probably be few and far between. And we are talking
> about a single that isn't too far off. I'm not privy
> to the way a thing "decides" if a signal is kosher or
> not (and of course it's ability to work with certain
> frequencies has to do with the tolerance of the
> individual components), but perhaps they could be
> tweaked to accept something a tad lower, but keep in
> mind the previous parenthetical info. Push it too hard
> and you might see a few sparks.


With a CRT monitor, where the horizontal deflection system is resonated 
at some harmonic of the expected hroizotnal scan frequency, then driving 
it at the wrong rate will cause damage.

But I don;t think that applies to an LCD or plasma panel. Most likely, if 
it can't make sense of what it's getting it'll display the 'no video' or 
'sync lost' or ... message and that'll be all.

-tony