Re: Preferred way of substituting TFT for CRT Monitor?

[Maciej W. Rozycki]

On Fri, 15 Jan 2016, martin.heppe...@dlr.de wrote:

> I have got a HP 9000/217 machine with a standard video card. This card 
> has a monochrome composite output (resolution is as low as about 
> 512x400, but I might replace it with a higher resolution card). A 
> small 9" HP monitor that I used for testing only shows me 2 or 3 bands 
> of the image and cannot capture the signal properly.
> 
> All I have are modern TFT monitors which usually have VGA and/or DVI 
> inputs, no separate R-G-B or monochrome jacks.
> 
> What is the preferred way to connect "old" composite video signals to 
> a modern TFT monitor without losing too much sharpness? I understand 
> that interpolation is an unavoidable problem.

 I don't know what the preferred way is, but as long as voltage levels 
are compatible (which I suppose could be tweaked with some circuitry 
anyway) you might be able to track down a standard VGA monitor that does 
sync on green and also has an option to switch to the greyscale mode.

 That's what I've been doing with a TURBOchannel MX monochrome graphics 
adapter which outputs an analogue composite 1V p-p signal (0.7V video, 
0.3V sync), 1280x1024@72Hz, on a TNC connector (the adapter is a pile of 
weirdness of its own BTW).  I have wired it via a TNC to BNC adapter and 
then a 5xBNC to DE-15 adapter (both off the shelf) to the green input of 
the monitor (obviously 4 of the 5 BNC inputs are loose), and in monitor 
configuration I chose the greyscale mode with input from the green line.  
It works just fine, and obviously there's no interpolation involved as 
the monitor simply applies the single signal to all the three colour 
components.

 It seems that with the switch to LCD panels sync on green support has 
become more common than it used to be with CRT displays; I don't know if 
this has to do with input circuitry commonly used with them or is it 
just that I've been lucky though.  If you were happy with a green rather 
than white image (which would certainly add spice to the vintage look of 
the system, as a green phosphor was not uncommon in the old days), then 
any sync-on-green display should do.

 HTH,

  Maciej

RE: Preferred way of substituting TFT for CRT Monitor?

[Martin.Hepperle]

Yesterday I checked the 9000/217 98204B combo with my oscilloscope and  I can 
confirm the 25kHz horz. frequency (1V down to 0.3V pulses every 40 us).
I cannot measure the pixel clock as my oscilloscope was too cheap (I had to 
compromise) and thus cannot sample at higher MHz rates. I only see that it goes 
from 1V to approx. 2.2V.
Just for my understanding: if I do the math: 512 pixels x 400 rows = 204'800 
pixels at 50 Hz I end up with 10.2 MHz and at 60 Hz = 12.3 MHz.
There is more "room" required for the retrace time, probably another 10% or so?
So I understand that the monitor must be capable of ~25 kHz and 10...14 MHz and 
that I better try before buy.

It is difficult to find specs for these HP 9000 video boards.
In case it is useful for someone ... my list below is still missing DIO-bus 
type (1 or 2) and signal frequencies.

98204B Video Board   medium resolution (512x390)monochrome for 
35721 monitor, DIO-1
98542A Monochrome Video Boardmedium resolution (512x400)monochrome
98543A Color Video Board medium resolution (512x400)16 colors
98544B Monochrome Video Boardhigh resolution (1024x768) monochrome
98545A Color Video Board high resolution (1024x768) 16 colors
98546A/B Monochrome Video Board  medium resolution (512x390)monochrome 
alpha/graphics, for 216/217 display compatibility
   (a pair of cards, compatible with 2136 and 217 displays (512x390, 25x80))
98547A Color Video Board high resolution (1024x768) 64 colors
98548A Monochrome Video Boardhigh resolution (1280x1024)high performance
98549A Color Video Board high resolution (1280x1024)high performance
98550A Color Video Board high resolution (1280x1024)high performance
98700A Graphics Display Station  high resolution (1024x768) 256 colors
98710A Graphics Accelerator  optional for 98700A
98720A High Performance Boardhigh resolution (1280x1024) nur HP-UX, 
requires 98724AA interface and 98784A monitor
98730A High Performance Boardhigh resolution (1280x1024) nur HP-UX
98722 memory upgrade optional for 98720A

Martin

Re: Preferred way of substituting TFT for CRT Monitor?

[r.stricklin]

The 98549A board is 1024x768, 6 planes (4 color, 2 overlay, at least under HP 
VUE -- perhaps there's a way it can make use of all 6 planes for color, but I 
don't know how). Otherwise, that matches what I've observed here.

ok
bear.

On Jan 21, 2016, at 8:51 AM,   
wrote:

> Yesterday I checked the 9000/217 98204B combo with my oscilloscope and  I can 
> confirm the 25kHz horz. frequency (1V down to 0.3V pulses every 40 us).
> I cannot measure the pixel clock as my oscilloscope was too cheap (I had to 
> compromise) and thus cannot sample at higher MHz rates. I only see that it 
> goes from 1V to approx. 2.2V.
> Just for my understanding: if I do the math: 512 pixels x 400 rows = 204'800 
> pixels at 50 Hz I end up with 10.2 MHz and at 60 Hz = 12.3 MHz.
> There is more "room" required for the retrace time, probably another 10% or 
> so?
> So I understand that the monitor must be capable of ~25 kHz and 10...14 MHz 
> and that I better try before buy.
> 
> It is difficult to find specs for these HP 9000 video boards.
> In case it is useful for someone ... my list below is still missing DIO-bus 
> type (1 or 2) and signal frequencies.
> 
> 98204B Video Board   medium resolution (512x390)monochrome 
> for 35721 monitor, DIO-1
> 98542A Monochrome Video Boardmedium resolution (512x400)monochrome
> 98543A Color Video Board medium resolution (512x400)16 colors
> 98544B Monochrome Video Boardhigh resolution (1024x768) monochrome
> 98545A Color Video Board high resolution (1024x768) 16 colors
> 98546A/B Monochrome Video Board  medium resolution (512x390)monochrome 
> alpha/graphics, for 216/217 display compatibility
>   (a pair of cards, compatible with 2136 and 217 displays (512x390, 
> 25x80))
> 98547A Color Video Board high resolution (1024x768) 64 colors
> 98548A Monochrome Video Boardhigh resolution (1280x1024)high 
> performance
> 98549A Color Video Board high resolution (1280x1024)high 
> performance
> 98550A Color Video Board high resolution (1280x1024)high 
> performance
> 98700A Graphics Display Station  high resolution (1024x768) 256 colors
> 98710A Graphics Accelerator  optional for 98700A
> 98720A High Performance Boardhigh resolution (1280x1024) nur HP-UX, 
> requires 98724AA interface and 98784A monitor
> 98730A High Performance Boardhigh resolution (1280x1024) nur HP-UX
> 98722 memory upgrade optional for 98720A
> 
> Martin
> 
> 


-- 
until further notice

RE: Preferred way of substituting TFT for CRT Monitor?

[tony duell]

> Just for my understanding: if I do the math: 512 pixels x 400 rows = 204'800 
> pixels
>  at 50 Hz I end up with 10.2 MHz and at 60 Hz = 12.3 MHz.
> There is more "room" required for the retrace time, probably another 10% or 
> so?

To avoid the inaccuracies from the unknown vertical retrace time (and unused 
lines, etc)
I would say that 512 pixels per line and 25kHz line time -> a pixel rate of at 
least 12.8MHz.
It will be higher than that due to the horizontal retrace time, of course

> So I understand that the monitor must be capable of ~25 kHz and 10...14 MHz 
> and that 
> I better try before buy.

Yes.

> It is difficult to find specs for these HP 9000 video boards.

I have no idea as to the resolution, but there is an HP98204A that outputs TV 
rate
(US or European I think) video.

-tony

Re: Preferred way of substituting TFT for CRT Monitor?

[Mouse]

> ... 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.)

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Re: Preferred way of substituting TFT for CRT Monitor?

[Mouse]

>> 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 don't know.  None of the monitors I've tried had 13W3.  (Complicating
the picture a little - I didn't mention it in my mini-rant because I
didn't want to make it even longer than it already was - is that I'm
trying to run at 1920x1080, 1600x1200, 1920x1200, or some such
resolution.  The cg14 can do 1920x1080 and 1600x1200 and I've learned
enough about how the resolution-setting words work that I should be
able to do 1920x1200.  The Asus at home - a VH236H - is 1920x1080.  I
don't like that it has HDMI, but I'm willing to accept that to get a
decently large resolution.)

> 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!

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Re: Preferred way of substituting TFT for CRT Monitor?

[ethan]

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

Re: Preferred way of substituting TFT for CRT Monitor?

[Martin.Hepperle]

> --

> Message: 8

> Date: Mon, 18 Jan 2016 15:39:38 -0500

> From: "j...@cimmeri.com<mailto:j...@cimmeri.com>" 
> <j...@cimmeri.com<mailto:j...@cimmeri.com>>

> To: General Discussion: On-Topic and Off-Topic Posts

><cctalk@classiccmp.org<mailto:cctalk@classiccmp.org>>

> Subject: Re: Preferred way of substituting TFT for CRT Monitor?

> Message-ID: 
> <569d4d8a.4080...@cimmeri.com<mailto:569d4d8a.4080...@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-to-VGA-Video-Konverter-/111506569501



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 +

> From: tony duell <a...@p850ug1.demon.co.uk<mailto:a...@p850ug1.demon.co.uk>>

> To: "General Discussion: On-Topic and Off-Topic Posts"

><cctalk@classiccmp.org<mailto:cctalk@classiccmp.org>>

> Subject: RE: Preferred way of substituting TFT for CRT Monitor?

> Message-ID:

>
> <a8192ef71c5c4946a240d25edc8f9448027e4...@exmbx15.thus.cor<mailto:a8192ef71c5c4946a240d25edc8f9448027e4...@exmbx15.thus.corp>

> p<mailto:a8192ef71c5c4946a240d25edc8f9448027e4...@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

RE: Preferred way of substituting TFT for CRT Monitor?

[Martin.Hepperle]

> What is the exact model number of the video card?
>
> I am assuming it's an HP98204 of some flavour. The HP98204A uses (US, RS170) 
> TV rates and
> can be connected to any composite monitor that expects that. A lot of TVs 
> (rather than monitors)
> in Europe can accept that and have composite inputs still, perhaps on a SCART 
> socket.
>
> However the more normal video card in the 9000/217 (aka HP9817) is the 
> HP98204B. This does
> have a composite output but at rather odd rates. There was a specal 'HP' 
> (actually a Samsung
> chassis, and it shows!) monitor for this. I thinkl finding somethng that will 
> lock to the video output
> of that card is going to be 'interesting'
>
> Do you have the original HP monitor? If so, what model is it?
>
> -tony

Hi Tony,

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.

I find many $20 converters/scalers for composite to VGA on amazon or ebay but I 
am not sure whether such a thing would work for me. Obviously they seem to work 
for many computer games (SNES, Nintendo) and for some hobby computers like C64, 
Amiga etc. (e.g. "RCA Composite AV S-Video to VGA Converter Box").

Next I see $50 devices like "Mini Composite RCA CVBS AV To HDMI Converter 
(Input: AV; Output: HDMI)" which may also be an option, but only seem to scale 
to a fixed HDMI resolution, which may be unsuitable for the HP-resolution of 
512x400 (or 512x390?).

Finally I see $200 converters/scalers which are a bit expensive just for trying 
to see whether they work (e.g. "Atlona AT-AVS100 Composite/S-Video to 
Component/VGA Scaler").

I have also contacted Jon from the HP-Museum to see what their solution is.

Regards,
Martin

RE: Preferred way of substituting TFT for CRT Monitor?

[tony duell]

> 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
will 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

Re: Preferred way of substituting TFT for CRT Monitor?

[nierveze]

hello
this circuit
http://nootropicdesign.com/ve/downloads/LM1881.pdf
separate sync signals from composite video,it may help you with some 
level adjustement,to apply your composite video to vga screens
maybe you can find commercial products on ebay but it will be more 
expensive 

best regards
alain Nierveze

Le 15/01/2016 12:39, martin.heppe...@dlr.de a écrit :

I have got a HP 9000/217 machine with a standard video card. This card has a 
monochrome composite output (resolution is as low as about 512x400, but I might 
replace it with a higher resolution card). A small 9" HP monitor that I used 
for testing only shows me 2 or 3 bands of the image and cannot capture the signal 
properly.

All I have are modern TFT monitors which usually have VGA and/or DVI inputs, no 
separate R-G-B or monochrome jacks.

What is the preferred way to connect "old" composite video signals to a modern 
TFT monitor without losing too much sharpness? I understand that interpolation is an 
unavoidable problem.

Searching the internet did not give me a clear answer. Do you have any 
recommendations?

Thank you, Martin

RE: Preferred way of substituting TFT for CRT Monitor?

[tony duell]

> 
> I have got a HP 9000/217 machine with a standard video card. This card has a 
> monochrome
>  composite output (resolution is as low as about 512x400, but I might replace 
> it with a higher
>  resolution card). A small 9" HP monitor that I used for testing only shows 
> me 2 or 3 bands
>  of the image and cannot capture the signal properly.

What is the exact model number of the video card?

I am assuming it's an HP98204 of some flavour. The HP98204A uses (US, RS170) TV 
rates and
can be connected to any composite monitor that expects that. A lot of TVs 
(rather than monitors)
in Europe can accept that and have composite inputs still, perhaps on a SCART 
socket.

However the more normal video card in the 9000/217 (aka HP9817) is the 
HP98204B. This does
have a composite output but at rather odd rates. There was a specal 'HP' 
(actually a Samsung
chassis, and it shows!) monitor for this. I thinkl finding somethng that will 
lock to the video output
of that card is going to be 'interesting'

Do you have the original HP monitor? If so, what model is it?

-tony

Re: Preferred way of substituting TFT for CRT Monitor?

[Mouse]

> All I have are modern TFT monitors which usually have VGA and/or DVI inputs,$

> What is the preferred way to connect "old" composite video signals to a mode$

Please don't use paragraph-length lines.

Any monitor that takes DE-15 ("VGA") or DVI-A input is, electrically
speaking, taking R-G-B signals; passive adapters exist (I've seen them
from DE-15 with 13W3 and 4BNC on the other end; I'm sure plenty of
others exist).  (Be careful with DVI; there are at least two kinds of
DVI, and it's just DVI-A, AIUI, that fits this description.)

Interpolation is not unavoidable.  The better flatscreens have a way to
tell the monitor to letterbox rather than scale signals whose
resolution is less than the monitor's.  _Good_ flatscreens have an
option to scale by the largest _integer_ factor possible, thus getting
image size without losing sharp pixel edges or aspect ratio.  (It's
depressing how advances in monitor technology have improved things to
the point where monitors routinely refuse to do what pretty much any
CRT monitor from decades past would.)

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RE: Preferred way of substituting TFT for CRT Monitor?

[Dave Wade]

Assuming you are in Germany I would use an LCD TV with SCART I assume
devices with SCART inputs are available there. Does Aldi in Germany do
weekly offers as in the UK. I especially bought one of their TV's because it
had a wide range of inputs. 

Dave

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of
> martin.heppe...@dlr.de
> Sent: 15 January 2016 11:39
> To: cctalk@classiccmp.org
> Subject: Preferred way of substituting TFT for CRT Monitor?
> 
> I have got a HP 9000/217 machine with a standard video card. This card has
a
> monochrome composite output (resolution is as low as about 512x400, but I
> might replace it with a higher resolution card). A small 9" HP monitor
that I
> used for testing only shows me 2 or 3 bands of the image and cannot
capture
> the signal properly.
> 
> All I have are modern TFT monitors which usually have VGA and/or DVI
> inputs, no separate R-G-B or monochrome jacks.
> 
> What is the preferred way to connect "old" composite video signals to a
> modern TFT monitor without losing too much sharpness? I understand that
> interpolation is an unavoidable problem.
> 
> Searching the internet did not give me a clear answer. Do you have any
> recommendations?
> 
> Thank you, Martin