20 Jan
2016
20 Jan
'16
2:25 a.m.
------------------------------
Message: 8
Date: Mon, 18 Jan 2016 15:39:38 -0500
From: "js at cimmeri.com<mailto:js at
cimmeri.com>" <js at cimmeri.com<mailto:js at cimmeri.com>>
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at
classiccmp.org<mailto:cctalk at classiccmp.org>>
Subject: Re: Preferred way of substituting TFT for CRT
Monitor?
Message-ID: <569D4D8A.4080505 at
cimmeri.com<mailto:569D4D8A.4080505 at cimmeri.com>>
Content-Type: text/plain; charset=ISO-8859-1;
format=flowed
. . .
You need a monitor (or converter) that supports 25khz.
Here's the extent of my own research:
25khz 640x400 SOG monitors
LCD
- NEC LCD1510+ (not tested)
- NEC LCD1810 (LA-1831JMW-1)
Mac + PC -- fair performance, poor scaling.
HP 300/98543 -- works, but banded background cannot
be completely
faded to black (I got rid of my 1810's for
this reason).
- Viewsonic Vp150
HP300/98543 -- works well, great background, colors
only fair.
- Viewsonic VP181
HP 300/98543 -- not perfect but can be adjusted ok.
banded background *can* be faded to black.
- J.
------------------------------
ah, this seems to become difficult...
Thanks for the data and recommendations. I will have a look at low H-freq. monitors on
ebay, maybe I have to revert to an old, heavy and large CRT. I see that many Viewsonic
TFT monitors start at 24kHz.
I also found
http://www.ebay.de/itm/Gonbes-GBS-8200-CGA-15kHz-EGA-25kHz-Arcade-JAMMA-PCB…
The technical data
(http://www.extremehardware.webspace.virginmedia.com/ebay_images/GBS-8200.pdf) says:
CGA / EGA - Auto Scan:
14.5 kHz - 16.5 kHz
23.5 kHz - 25.5 kHz <<<< this may fit the HP card?
3 0.5 kHz - 32.5 kHz
Martin
------------------------------
Message: 9
Date: Mon, 18 Jan 2016 21:07:27 +0000
> From: tony duell <ard at p850ug1.demon.co.uk<mailto:ard at
p850ug1.demon.co.uk> To: "General Discussion: On-Topic and Off-Topic
Posts"
<cctalk at
classiccmp.org<mailto:cctalk at classiccmp.org>>
Subject: RE: Preferred way of substituting TFT for CRT
Monitor?
Message-ID:
> <A8192EF71C5C4946A240D25EDC8F9448027E4311 at
EXMBX15.thus.cor<mailto:A8192EF71C5C4946A240D25EDC8F9448027E4311 at
EXMBX15.thus.corp Content-Type: text/plain; charset="us-ascii"
> indeed this machine has a 98204B video board
(intended to work with a 35721
monitor,
> which I don't have). I have not yet found
the specs for its composite signal.
It is normal composite video voltage levels with
faster-than-normal horizontal scan rate.
If you have a frequency counter (or something that can
be used as one, then put the 98204B
text board in the topmost position of the 9817,
leaving out the graphics board
(the machine ill run without it) and take the top
casing off the 9817. Take care to avoid the
live mains and worse on the PSU board, power it up,
and check the HS and VS pins of the 6845
(the only 40 pin IC on the board)
Most, if not all, cheap composite video converters
assume US or European TV rates and are
not going to lock to this thing. If anybody knows of
an interface that will work,
I'd be interested to know about it too (I have a
9817 with the 98204B card, fortunately
I do have the right montor for it).
-tony
------------------------------
Tony,
thank you for your explanations. As I understand, the unusual low horizontal frequency is
the main problem.
I saw that the card has a switch to toggle 50/60Hz vertical frequency (EU/US, original
setting was at 60 Hz), but this did not help.
I will see whether I can use my oscilloscope to catch the frequencies as I could not find
a technical description of the 98204B.
... and I thought today such a simple problem could be easily solved with modern
technology...
Martin
20 Jan
20 Jan
7:22 a.m.
... and I thought today such a simple problem could be
easily solved with mo$
It could. But in the current race to the bottom, nobody makes a
monitor that does that, because investing the same resources in
building for the majority market is perceived as having greater ROI.
I've noticed it myself. I'm looking for a flatscreen that can sync to
something my SS20 can put out - I have an Asus that syncs to it just
fine, but it's not made any longer, and more modern monitors are, it
appears, significantly less functional.
As I've put it on a few occasions, monitor technology has imrpoved to
the point where it can't do what any CRT from two decades ago could.
(That's a slight exaggeration, admitted, but not much of one.)
/~\ The ASCII Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
7:52 a.m.
I've noticed it myself. I'm looking for a
flatscreen that can sync to
something my SS20 can put out - I have an Asus that syncs to it just
fine, but it's not made any longer, and more modern monitors are, it
appears, significantly less functional.
Will the Samsung/Dell monitor with the 13w3 work? I had one on the SWS
Sparcstation 5 front end to Cray J932SE. I think I have one at home, can
get model #.
--
Ethan O'Toole
8:12 a.m.
I've
noticed it myself. I'm looking for a flatscreen that can sync
to something my SS20 can put out - I have an Asus that syncs to it
just fine, but it's not made any longer, and more modern monitors
are, it appears, significantly less functional.
Will the Samsung/Dell monitor with
the 13w3 work? I had one on the SWS Sparcstation 5 front end to Cray
J932SE. I
think I have one at home, can get model #.
If its native resolution is something near the above range - on the
order of two million pixels - then I'd be very interested. If you had
it running at such a resolution I'd be even more interested.
Silly me. I should have known a crowd this awesome would include
someone who'd know of an example of what I'm looking for!
/~\ The ASCII Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents-montreal.org
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
3259
days inactive
3259
days old
3 comments
3 participants
participants (3)
-
ethan＠757.org -
Martin.Hepperle＠dlr.de -
mouse＠Rodents-Montreal.ORG