TV ---> CGA Monitor
 

In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B- sync as
inputs. In fact there was one monitor I had that had an entire section of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?

"Steve Lewinsky" writes:

In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B- sync as
inputs. In fact there was one monitor I had that had an entire section of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?

The quick answer is: probably for the RGB, at the output of the
video chip. And, possibly for the sync.

However, there could be other issues like if the tuner doesn't see
any signal, it may simply diable the picture (and sound) elsewhere,
so there could be additional annoying details to address.

If you have a particular TV in mind, go find the Sams' Photofact for
the set and see if these signals.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

Sam Goldwasser wrote:
"Steve Lewinsky" writes:


In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B- sync as
inputs. In fact there was one monitor I had that had an entire section of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?


The quick answer is: probably for the RGB, at the output of the
video chip. And, possibly for the sync.

However, there could be other issues like if the tuner doesn't see
any signal, it may simply diable the picture (and sound) elsewhere,
so there could be additional annoying details to address.

If you have a particular TV in mind, go find the Sams' Photofact for
the set and see if these signals.

Hi Sam...

I respectfully submit that the result could be a serious
safety issue...

I believe they do (or did) require opto isolators.

Take care.

Ken

Steve Lewinsky wrote:

In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B- sync as
inputs. In fact there was one monitor I had that had an entire section of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?


A CGA monitor is TTL levels on the video and sync, while the TV is 1V
P-P NTSC or other video system so you have to convert the signals to
drive the TV as a CGA monitor.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida

"Steve Lewinsky" wrote in message
...
In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B- sync
as
inputs. In fact there was one monitor I had that had an entire section of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?



I've seen it done, it's easier to just buy a proper monitor though, they'll
usually have better convergence and geometry anyway.

"Ken Weitzel" wrote in message
news:_vtHe.82466$5V4.1839@pd7tw3no...


Sam Goldwasser wrote:
"Steve Lewinsky" writes:


In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B-
sync as
inputs. In fact there was one monitor I had that had an entire section
of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?


The quick answer is: probably for the RGB, at the output of the
video chip. And, possibly for the sync.

However, there could be other issues like if the tuner doesn't see
any signal, it may simply diable the picture (and sound) elsewhere,
so there could be additional annoying details to address.

If you have a particular TV in mind, go find the Sams' Photofact for
the set and see if these signals.

Hi Sam...

I respectfully submit that the result could be a serious
safety issue...

I believe they do (or did) require opto isolators.



Not optoisolators, but most older arcade monitors do require isolation
transformers.

"Michael A. Terrell" wrote in message
...
Steve Lewinsky wrote:

In the arcade machines that I collect, we use CGA type monitors from
Wells-Gardner, Electrohone...etc. These monitors are apparently just the
basic circuits from a TV without the tuner. They use standard R-G-B-
sync as
inputs. In fact there was one monitor I had that had an entire section
of
parts missing that was the tuner circuit and stuff.

So my question is.. on a Color TV is there a spot where I can tap in and
input R-G-B-Sync to convert a Television into a CGA monitor?


A CGA monitor is TTL levels on the video and sync, while the TV is 1V
P-P NTSC or other video system so you have to convert the signals to
drive the TV as a CGA monitor.



Arcade monitors are CGA resolution, but they're analog RGB just like a TV.

James Sweet wrote:

Arcade monitors are CGA resolution, but they're analog RGB just like a TV.


Then they are not CGA monitors. They are NTSC RGB monitors.

--
Link to my "Computers for disabled Veterans" project website deleted
after threats were telephoned to my church.

Michael A. Terrell
Central Florida