2 Nov
2006
2 Nov
'06
3:07 p.m.
On 11/3/06, Chris M <chrism3667 at yahoo.com> wrote:
Naturally. I was simply thinking that the OP needed _some_ color
monitor and might have access to a multisync that could scan to lower
rates than VGA.
--- Ethan Dicks <ethan.dicks at gmail.com>
wrote:
I did miss the part about a "modern monitor". Sorry about that.
You _would_ need some sort of scan doubler to get around that issue.
Internal scan doublers were common with Amigas since the custom
chipset was very NTSC or PAL-centric, not VGA-centric. The A3000 had
one built-in, and there were several options for the video slot on an
A2000. ISTR the price in the day for a scan doubler card was at least
$150 - they entirely buffered a frame in local RAM and squirted it out
at 31.5KHz on a VGA connector. Effective, but complicated.
So... start with a multisync that can handle the
requisite sync frequency from your RBGI-equipped CPU.
Something like an old NEC-3D
can sync down to the NTSC range (~15KHz horizontal).
that's the whole problem though. Those monitors are
difficult to find. What I wouldn't do for one of the
early 19" NEC multisyncs... In essence, the intensity is "ignored"
already with
the T2K. It displays 8 simultaneous colors from a
palette of 16. Whether the native palette causes the
intensity to default to high or low, I don't know.
Ah... didn't know the T2K was only 8 colors.
just work out
the necessary resistance to drop
TTL levels down to the high end of what the VGA
monitor is expecting (0.7VDC == max intensity?)
Sounding more and more feasible. Problem is the sync
issues need to be worked out first. > If you want to be able to tweak the color
balance,
> one could just use 3 variable resistors that can span the range near
> the value you would have used for each fixed resistor...
Ok, we're on the same page then. Sounds like it
just
might work. I had this whole problem so complicated in
my head until today. Uy
I did just remember there is one "exception" to the simple case I
outlined... brown. We had a discussion here some months ago about how
one of the IBM color monitors "knew" brown was funny and had some
compensation circuit. I'll just restate that my suggestion is an
approximation, and you might or might not be satisfied with the
results - presuming you can locate an older multisync monitor in the
first place. The general solution (using a 2006-era monitor) is
likely to be an expensive route.
-ethan