Author Topic: Connecting a CPC+ to a 15Khz VGA monitor  (Read 3234 times)

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Offline ||C|-|E||

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #25 on: 22:57, 11 February 18 »
Thanks @||C|-|E||. Really valuable info here  :)

Do you have any extra info about these missing capacitors? I'd like to build a proper cable in the future, so I'll definitely try to add these caps.

Just in case, if I mess up something in the cable, could there be some damage to the CPC+? or is this relatively safe to perform? I'm very sentimental about this machine, so I want to avoid any risk of damaging it.

Thanks!


No, by adding the caps to the cable you won't do any damage  :)


Offline ||C|-|E||

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #26 on: 23:05, 11 February 18 »
The 4:3 monitor feels so good... Unfortunately, big CRTs are so BIG. Were there shortneck monitors?




Do you mean, CRTs with shorts tubes? heh, it is difficult because certain length is needed to accelerate the electrons with a given voltage and to have proper aperture and cover the full screen  :)  Same happens in an electron microscope, where they need to travel a particular distance before hitting the target. You could increase the voltage, but this would cause other problems.

Offline Gryzor

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #27 on: 17:18, 12 February 18 »
Do you mean, CRTs with shorts tubes? heh, it is difficult because certain length is needed to accelerate the electrons with a given voltage and to have proper aperture and cover the full screen  :)  Same happens in an electron microscope, where they need to travel a particular distance before hitting the target. You could increase the voltage, but this would cause other problems.
 


Yeah, I know, but there *were* CRT TVs with short necks. It's just that I've never seen a monitor like that.

Offline ||C|-|E||

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #28 on: 21:29, 12 February 18 »
Do you have any particular model of TV in mind?  :) I would like to have a look at them  :D

Offline Bryce

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #29 on: 10:01, 13 February 18 »
 


Yeah, I know, but there *were* CRT TVs with short necks. It's just that I've never seen a monitor like that.

Some of the really big CRT Monitors (we used to have them in our CAD department) had quite short tube lengths. I think they were Eizo or Silicon Graphics monitors.

Bryce.

Offline VincentGR

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #30 on: 14:20, 13 February 18 »
I remember some short neck TVs too, I saw some a couple of years ago in a junk yard but can't really remember if they were b/w.

Offline Gryzor

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #31 on: 15:06, 13 February 18 »
Some of the really big CRT Monitors (we used to have them in our CAD department) had quite short tube lengths. I think they were Eizo or Silicon Graphics monitors.

Bryce.


Ah yeah, the cheap stuff.


Do you have any particular model of TV in mind?  :) I would like to have a look at them  :D
   


Nothing in particular... I know I did have the top-of-line model from the last Sony CRT series ca. 2005 and for its size (32" - huuuuge!!!) it was quite short. But what the model was... no idea :(

Offline Joseman

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #32 on: 14:01, 21 February 18 »
In the end, the connections looks like this. The only change wrt the previous one is that I rewired VGA pins 10 and 5 to SCART 4 & 5.
Code: [Select]
Composite Sync (13)
   |
   |   RGB Switch (14)
   |   |           GND (5)
---|---|-----------|---
\  0 X 0 X X X X X 0 X |
 `                     |
 \ X X 0 X 0 X 0 0 X X |
  -----|---|---|-|-----
       |   |   |  GND (10)
       |   |   Blue (3)
       |   Green (2)
       Red (1)

Hi!

Today my new monitor arrived! the Benq 19" version.

I'll make the cable this afternoon, one question:

The RGB Swich to 14 (Vsync) is necessary? what is the point to connect a simple RGB analog signal to a Vsync/clock signal?

P.S. I promise to put a lot of pictures if the thing goes well!!

Offline Bryce

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #33 on: 14:26, 21 February 18 »
The CPC doesn't have an "RGB Switch" output, so I assume he's referring to the SCART pin names, in which case it will depend on how his SCART cable was built.

Bryce.

Offline adolfo.pa

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #34 on: 14:51, 21 February 18 »
The RGB Swich to 14 (Vsync) is necessary? what is the point to connect a simple RGB analog signal to a Vsync/clock signal?

To be honest, I don't know :-) I wired that PIN because I found a diagram online that did that for the Mist, so I tried and it didn't hurt. But you probably know more than me about this subject.

Are you going to put the capacitors in the cable? I got my C4CPC recently, and the vertical bars look horrible in the cartridge menu system! They're much more noticeable when using the plus extended palette for the backgrounds (although it depends on the color).

P.S. I promise to put a lot of pictures if the thing goes well!!

I'll be waiting ;-)

Good luck!

Offline Joseman

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #35 on: 15:17, 21 February 18 »
To be honest, I don't know :-) I wired that PIN because I found a diagram online that did that for the Mist, so I tried and it didn't hurt. But you probably know more than me about this subject.

You wired the 14 VGA pin to where on the cpc side?

as Bryce told there isn't this signal on the cpc side...

Offline adolfo.pa

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #36 on: 15:49, 21 February 18 »
TLDR; I don't know for sure.

To avoid the need to solder anything, I reused my CPC->SCART cable, but the thing is that the Scart head is glued together (literally), so I didn't open it out of fear of breaking it. As a consequence, I had to treat this cable as a black box; to move forward with the thing, I assumed the SCART side of it would be more or less equivalent to the Mist cable, checked other CPC SCART cables to see if things were much different, an finally tried it to see if it worked.

So yes, it is possible that the Scart RGB switch is not connected to anything.

Offline Bryce

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #37 on: 16:47, 21 February 18 »
You wired the 14 VGA pin to where on the cpc side?

as Bryce told there isn't this signal on the cpc side...

I would leave pin 14 disconnected.

Bryce.

Offline adolfo.pa

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #38 on: 14:08, 02 March 18 »
Hey @Joseman , any news about this?

Offline Joseman

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Re: Connecting a CPC+ to a 15Khz VGA monitor
« Reply #39 on: 01:28, 03 March 18 »
Hey @Joseman , any news about this?

Yes, i have a lot of photos from the monitor working on the cpc.

I've been working on another project, soon i will upload the pics.

overall is all good, i'm happy with it...