9 Mar
2010
9 Mar
'10
10:28 a.m.
Hi,
I need scematics of RGB to VGA converter.
I want to connect Wheel Balancer machine to computer VGA monitor.
Old monitor is VALVO VCC93/00 fixed frequency (15KHz) and have R, G, B and
common Sync signals.
I would be grateful if you can help me!
Best regards,
Jovica
9 Mar
9 Mar
3:20 p.m.
On Tue, Mar 9, 2010 at 4:28 AM, Jovica Stojoski <stojoskij at ikomline.net>wrote:
Hi,
I need scematics of RGB to VGA converter.
I want to connect Wheel Balancer machine to computer VGA monitor.
Old monitor is VALVO VCC93/00 fixed frequency (15KHz) and have R, G, B and
common Sync signals.
I would be grateful if you can help me!
Amiga people have this exact problem all the time. There's a device called
the ToastScan or something like that. They're dreadfully expensive on
ebay. But you might be able to get the plans for it. It plugged into the
RGB output on the back of the amiga and converted to VGA.
A less elegant solution would be to find an old amiga 1084 (or similar)
monitor. They're relatively cheap. It should be able to display the 15khz
signal just fine. I know it's not a flat panel LCD though.
brian
3:31 p.m.
Jovica Stojoski wrote:
I need scematics of RGB to VGA converter.
I want to connect Wheel Balancer machine to computer VGA monitor.
Old monitor is VALVO VCC93/00 fixed frequency (15KHz) and have R, G, B and
common Sync signals.
I would be grateful if you can help me!
This would seem to be WAY off topic even for cctalk, but hey-ho...
Go find yourself a Microvitec Cub or Philips CM8833 monitor -- either of
these should be easily obtainable for far less than a scan converter.
There are other monitors that should work -- the Acorn AKF17, for
instance, was a reboxed version of the CM8833, and dozens of other
companies made CRT-type TV monitors.
Converting from 15kHz fixed frequency to VGA (which has a line frequency
of 31.5kHz) would most likely involve a triple A/D converter, a
dual-ported frame buffer RAM, a triple D/A converter, and some form of
timing controller (I'd probably use an FPGA with an internal PLL -- use
the PLL to double the line rate of the incoming signal).
Another option might be an TV with a SCART input -- wire your RGB and
sync signals to a SCART plug, then plug those into the TV. Quality isn't
going to be particularly stellar, though, especially on a cheap TFT
monitor. The CM8833 et al were all designed as computer monitors, and
are far better suited to displaying text and graphics.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
5:10 p.m.
On 9 Mar 2010 at 11:28, Jovica Stojoski wrote:
Old monitor is VALVO VCC93/00 fixed frequency (15KHz)
and have R, G, B
and common Sync signals.
Chinese converters are available from a number of sources for a very
reasonable price. Consider, for example, eBay item 250593765979.
--Chuck
5:50 p.m.
Jovica Stojoski wrote:
Hi,
I need scematics of RGB to VGA converter.
we use one of these, it's almost universal , RGB/CGA/EGA/YUV to VGA
Converter
more details on the website
http://www.jammaboards.com/store/cga/ega/yuv-to-vga-converter-pcb-gbs-8220/…
only $50
=Dan
9:30 p.m.
Dan Roganti wrote:
Jovica Stojoski wrote:
Dan,
Interesting to note this is the same product mentioned by Chuck in the
previous post (aka eBay item 250593765979)
Has anyone tried this with their amigas? I've been interesting in
getting one of these for quite some time.
Keith
Hi,
I need scematics of RGB to VGA converter.
we use one of these, it's almost universal , RGB/CGA/EGA/YUV to VGA
Converter
more details on the website
http://www.jammaboards.com/store/cga/ega/yuv-to-vga-converter-pcb-gbs-8220/…
only $50
=Dan
14 Mar
14 Mar
7:37 p.m.
As previously discussed in this list, and documented on
http://www.oldskool.org/pc/cgacal , CGA monitors have circuitry to
change color index #6 to a different color. CGA also has a fourth
"intensity" pin. Does anyone know if some sort of specially-wired cable
might be able to convert 4-pin RGBI to something these kinds of
converters can take as input and everything will still look decently?
I ask because I have a need to do video capture of native CGA output.
Don't ask :-)
The best solution I've come up with is to use an older VGA card (1990 or
before) that comes with utilities to force it into CGA emulation --
forces 400 scandoubled lines, forces the 8x8 font, and ports react
properly to MC6845 writes. This is 95% of the way there, but it's still
a 70Hz refresh rate, not 60. All ideas welcome.
On 3/9/2010 11:50 AM, Dan Roganti wrote:
Jovica Stojoski wrote:
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
Hi,
I need scematics of RGB to VGA converter.
we use one of these, it's almost universal , RGB/CGA/EGA/YUV to VGA
Converter
more details on the website
http://www.jammaboards.com/store/cga/ega/yuv-to-vga-converter-pcb-gbs-8220/…
only $50
=Dan
9:29 p.m.
As previously discussed in this list, and documented on
http://www.oldskool.org/pc/cgacal , CGA monitors have circuitry to
change color index #6 to a different color. CGA also has a fourth
"intensity" pin. Does anyone know if some sort of specially-wired cable
might be able to convert 4-pin RGBI to something these kinds of
converters can take as input and everything will still look decently?
It's goign to take more than a cable. THere must be components involved.
I ask because I have a need to do video capture of native CGA output.
Don't ask :-)
If this is a real CGA card, there is most likely an NTSC-compatible
composoite colour output available too. It may be on an RCA phono socket
on the bracket (IBM had that), a header inside, or sometimes on pin 7
(otherwise unused) of the DE9 socket.
You might look at the IBM CGA card scheamtics. They include the circuit
to encode the RGBI signals to NTSC composite video.
-tony
10:22 p.m.
On 3/14/2010 4:29 PM, Tony Duell wrote:
If this
is a real CGA card, there is most likely an NTSC-compatible
composoite colour output available too. It may be on an RCA phono socket
on the bracket (IBM had that), a header inside, or sometimes on pin 7
(otherwise unused) of the DE9 socket.
The colors are not the same, which is why I can't use that technique.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
15 Mar
15 Mar
9:15 p.m.
On 3/14/2010 4:29 PM, Tony Duell wrote:
If
this is a real CGA card, there is most likely an NTSC-compatible
composoite colour output available too. It may be on an RCA phono socket
on the bracket (IBM had that), a header inside, or sometimes on pin 7
(otherwise unused) of the DE9 socket.
The colors are not the same, which is why I can't use that technique.
A few suggestions :
1) Have you tried adjusting the 14.3...MHz clock trimmer in the PC? The
original IBM machines (including the 5161 expansion unit), and many older
clones, have a trimmer across the crystal that's used for the 14.3...MHz
oscillator (this is divided down to get the 3.58...MHx NTSC colour
reference, of course). The IBM manuals recomend adjusting this if the
colours are misisng/incorrect. I am not sure it will do any good, but it
can't hurt.
2)If the colours are wrong but consistent, can't you modify them after
digitising them?
3) Take a look at the CGA monitor scheamtic, particularly the part from
the RGBI TTL inputs to the CRT cathodes. This will show you how the 4 TTL
signals are ocmbined to produce analogue RGB signals.
-tony
16 Mar
16 Mar
1:45 a.m.
On 3/15/2010 4:15 PM, Tony Duell wrote:
1) Have
you tried adjusting the 14.3...MHz clock trimmer in the PC? The
original IBM machines (including the 5161 expansion unit), and many older
clones, have a trimmer across the crystal that's used for the 14.3...MHz
oscillator (this is divided down to get the 3.58...MHx NTSC colour
reference, of course). The IBM manuals recomend adjusting this if the
colours are misisng/incorrect. I am not sure it will do any good, but it
can't hurt.
I have tried, and all it does is change the hue (slightly). It doesn't
make the colors any closer to their RGB equivalents.
Mind you, some of the color combinations possible in composite color
mode are fantastic
2)If the colours are wrong but consistent, can't
you modify them after
digitising them?
Not easily. It's an analog capture and there are luma/chroma cross-talk
issues that make things worse. I would only do that if desperate, and
it still wouldn't look right.
3) Take a look at the CGA monitor schematic,
particularly the part from
the RGBI TTL inputs to the CRT cathodes. This will show you how the 4 TTL
signals are combined to produce analogue RGB signals.
I would need to go to school to understand what I would be looking at.
But my brother works at UL as a tester and has an electronics degree, so
I will ask him.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
8:09 p.m.
2)If the
colours are wrong but consistent, can't you modify them after
digitising them?
Not easily. It's an analog capture and there are luma/chroma cross-talk
issues that make things worse. I would only do that if desperate, and
it still wouldn't look right. 3) Take a look at the CGA monitor schematic,
particularly the part from
the RGBI TTL inputs to the CRT cathodes. This will show you how the 4 TTL
signals are combined to produce analogue RGB signals.
I would need to go to school to understand what I would be looking at.
17 Mar
17 Mar
2:54 a.m.
On 3/16/2010 3:09 PM, Tony Duell wrote:
For the record, you are one of a kind. I say that with the sincerest
form of flattery.
Had I enough free time, I could learn it too, but I don't have much
these days. My free time in my youth was spent learning the hardware
What are you really trying to do? Waht is the machine
you are taking the
outputs from, and what are you trying to do with them?
Trying to capture the output of a program running on an IBM 5160 that
only looks correct via CGA RGB output.
I would need
to go to school to understand what I would be looking at.
Err, I didn't. For the record I have never had a single formal class in
any form of electronicvs. from the outside (ie. assembler programming), not the
inside.
I am pretty darn certain that this can't be done
with a simple cable, and
it can't be done properly with passive components. You are going to need
some simple chips to do this.
The input stage of a CGA monitor will kelp (and will show you how colour
6 is handled), but you will need to make modifications.
Fair enough; I'll retain this to show my electronics-savvy brother.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
8:06 p.m.
On 3/16/2010 3:09 PM, Tony Duell wrote:
Right. And what are you capturing it on? What inputs _exactly_ do you
have? For example, do you have separate syncs, composite sync, or
sync-on-green?
What are you really trying to do? Waht is the
machine you are taking the
outputs from, and what are you trying to do with them?
Trying to capture the output of a program running on an IBM 5160 that
only looks correct via CGA RGB output. I would
need to go to school to understand what I would be looking at.
Err, I didn't. For the record I have never had a single formal class in
any form of electronicvs.
Had I enough free time, I could learn it too, but I don't have much
these days. My free time in my youth was spent learning the hardware
from the outside (ie. assembler programming), not the inside.
I have the opposite problem. I learnt hardware first. Which means I tend
to think about probramming as to what it will do to the hardware
(somtimes at a very low level).
-tony
20 Mar
20 Mar
5:12 a.m.
On 3/17/2010 3:06 PM, Tony Duell wrote:
I'm not sure I understand the question: There is no capture device made
that can do it, so I have no device to capture from.
I do have an Extron unit that can convert RGB TLL to analog RGBH with
sync on green but it doesn't handle the *I* of RGBI, nor the recoloring
of color index #6.
I have a solution that works for 95% of the cases that don't involve
timing tricks (like switching palettes mid-screen) that is cheating, but
it seems to work: I have an old ATI VGA with a program that can put the
card into a CGA-like mode where the register writes behave like CGA and
not like VGA -- palette and background changes work like they should on
CGA, the font is 8x8 like CGA, and the output is 400 lines (200
line-doubled) and that can be captured with any vga->video converter.
It's the last 5% I'm striving for, since the stuff worth capturing is
the stuff that uses tricks to extend CGA.
Ah, but then you would like assembler -- that's where our two worlds meet.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
On 3/16/2010 3:09 PM, Tony Duell wrote:
Right. And what are you capturing it on? What inputs _exactly_ do you
have? For example, do you have separate syncs, composite sync, or
sync-on-green? What are you really trying to do? Waht is the
machine you are taking the
outputs from, and what are you trying to do with them?
Trying to capture the output of a program running on an IBM 5160 that
only looks correct via CGA RGB output. Had I enough
free time, I could learn it too, but I don't have much
these days. My free time in my youth was spent learning the hardware
from the outside (ie. assembler programming), not the inside.
I have the opposite problem. I learnt hardware first. Which means I tend
to think about probramming as to what it will do to the hardware
(somtimes at a very low level).
6:38 p.m.
On 3/17/2010 3:06 PM, Tony Duell wrote:
I'm not sure I understand the question: There is no capture device made
that can do it, so I have no device to capture from.
Ireally don't understand what you want to do. I understand you have a
5160 with a CGA card, and you want to use it with something other than
the oriignal CGA monitor. My question is what is this 'something', what
inputs does it have _precisely_.
TO work out how to interface 2 things i generally have to know what those
things are. The CGA card I know (darn it, I am using one here). The other
device I have no idea on.
-tony
On 3/16/2010 3:09 PM, Tony Duell wrote:
Right. And what are you capturing it on? What inputs _exactly_ do you
have? For example, do you have separate syncs, composite sync, or
sync-on-green? What are you really trying to do? Waht is the
machine you are taking the
outputs from, and what are you trying to do with them?
Trying to capture the output of a program running on an IBM 5160 that
only looks correct via CGA RGB output.
21 Mar
21 Mar
5:12 a.m.
On 3/20/2010 1:38 PM, Tony Duell wrote:
Ireally don't understand what you want to do. I understand you have a
5160 with a CGA card, and you want to use it with something other than
the oriignal CGA monitor. My question is what is this 'something', what
inputs does it have _precisely_.
I wish to connect a device to the CGA RGB output that will convert it to
something I can capture into a computer. Ideally that would be YCrCb as
I have a betacam sp capture card that can do very nice 8/10/12-bit
capture from an SD or HD source... but I'd settle for Y/C (s-video) at
this point.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
7:39 p.m.
On 3/20/2010 1:38 PM, Tony Duell wrote:
Ireally don't understand what you want to do. I understand you have a
5160 with a CGA card, and you want to use it with something other than
the oriignal CGA monitor. My question is what is this 'something', what
inputs does it have _precisely_.
I wish to connect a device to the CGA RGB output that will convert it to
something I can capture into a computer. Ideally that would be YCrCb as
I have a betacam sp capture card that can do very nice 8/10/12-bit
capture from an SD or HD source... but I'd settle for Y/C (s-video) at
this point.
I would avoid S-vidoe, I suspect even with separate Y and C thare's a
possibility of of colour problems
SO what you actually want is Y (including composite sync), R-Y and B-Y?
Originally you were talking aobut analouge RGB.
I am also wondeiring if you could capture the digital data as it comes
out of the CGA card. It's not that high a data rate, and it seems rather
perverse to take digital signals, comvert them to analogue and then
redigitse them again.
[I find the VGA inoptu on our LCD TV to be a bit silly. The data sexists
in digitla form in the computer, you turn it into analogue signals to
fied to the TV, and then redigitse them for display. Why?]
-tony
10:33 p.m.
On 3/21/2010 2:39 PM, Tony Duell wrote:
SO what
you actually want is Y (including composite sync), R-Y and B-Y?
As a fallback to your interesting idea (see below).
I am also wondeiring if you could capture the digital
data as it comes
out of the CGA card. It's not that high a data rate, and it seems rather
perverse to take digital signals, comvert them to analogue and then
redigitse them again.
RGB TTL, as implemented on IBM CGA+5153 monitor, is capable of producing
a visible display area of 640x200x60x4=30720000 bits of information a
second, which would be under 4mbytes a second, so technically you're
right, it's not much data to capture. It's more than that due to
overscan and retrace, of course, but even with overhead it's reasonable.
I had never thought of that as an option.
It's still beyond my abilities to design and implement, but that would
clearly be the very best option.
[I find the VGA inoptu on our LCD TV to be a bit
silly. The data sexists
in digitla form in the computer, you turn it into analogue signals to
fied to the TV, and then redigitse them for display. Why?]
As an extra option for legacy hookups. You're never supposed to use
that if your output device supports HDMI or DVI etc.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
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18 comments
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participants (8)
-
ard＠p850ug1.demon.co.uk -
brianlanning＠gmail.com -
cclist＠sydex.com -
classiccmp＠philpem.me.uk -
keithvz＠verizon.net -
ragooman＠comcast.net -
stojoskij＠ikomline.net -
trixter＠oldskool.org