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RGB for G7000

Started by VideopacBelgium, June 16, 2009, 12:45:43 AM

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VideopacBelgium

Quote from: Seob on July 23, 2009, 06:30:28 PM
@Videopakbelgium

Can you draw a circuit diagram of your pcb? I don't understand the diagram rene has put on the net. I want to build one as well.

Ok, now it works, I'll draw the final circuit diagram of the rgb pcb.
Videopac digger

VideopacBelgium

Oops! The videopac with RGB pcb has worked during four hours and the green color does not work anymore!
I checked the green wire from the scart to the rgb pcb and from the rgb pcb to the G7000, they are ok.
Videopac digger

Rene_G7400

Can you show a picture of how it looks on your TV screen?

VideopacBelgium

#18
Hi!
This is very strange!


Intro: QUEL JEU? all colors.

Baseball: no green background and strange colors.

Mr.Roboto: SELECT GAME all colors and the characters "a la Matrix" are green.

Turtles: No green

4 in a Row: Green dog, name HOUNDOG in green but the tiles are not green and red!
Videopac digger

Rene_G7400

I think there is a problem with the blanking signal, because the strange colors appear when the background color is something else than black.
(IC 653 in the circuit diagram of the G7200.)

VideopacBelgium

Rene, you are right.
I badly connected two wire, I reversed the input with the output of the inverter 74LS04 (from blanking).... 
Now it works very well.
Thanks again for your help.
Videopac digger

VideopacBelgium

Hi!
Now I try to add an RGB output on my old G7000/02 with the RGB pcb from a 7200.
I add a small pcb with IC 74LS04 and IC 74LS08.
The old G7000 works fine with the RF output, when I plug the DIN8 into the DIN8 socket, the G7000 freezes and reboots, the TV turns to RGB but I have a black screen with sound.
What about the switch inside the DIN8 socket on the 7200 pcb?
Thanks

http://www.ddrbelgium.eu/7000RGB7200.jpg
Videopac digger

Rene_G7400

If the G7000 resets you've probably caused a short circuit.
The switch inside the DIN-8 socket is useless, you should remove resistor R713 (100 Ohm according to the circuit diagram).

VideopacBelgium

Quote from: Seob on July 23, 2009, 06:30:28 PM
@Videopakbelgium

Can you draw a circuit diagram of your pcb? I don't understand the diagram rene has put on the net. I want to build one as well.

@ Seob
Hi!
It's enough difficult to draw a circuit diagram of my pcb because the 2nd one I build is not the same as the 1st, I'm soldering each element and wire step by step. If you want I can build one for you for the price of the elements, this is not very expensive.
Videopac digger

VideopacBelgium

@ Rene_G7400

Hi!
Is IC SN7400 the same as 74LS04 ? (as inverter for the rgb pcb)
Thanks.
Videopac digger

Rene_G7400

Quote from: VIDEOPAKBELGIUM on August 12, 2009, 05:14:48 PM
Is IC SN7400 the same as 74LS04 ? (as inverter for the rgb pcb)

No. You can use the SN7400 as an inverter, but the pinout is not the same.

VideopacBelgium

Hi!
Hard to find some ICs in Belgium.
Can I use one IC 74LS07 as one IC 7407 ?
Thanks.
Videopac digger

Seob

What would be the cost, for building one?
8 bits of fun

Rene_G7400

Quote from: VIDEOPAKBELGIUM on August 18, 2009, 11:48:38 PM
Hard to find some ICs in Belgium.
Can I use one IC 74LS07 as one IC 7407 ?

The RGB output levels might not be exactly the same, but I don't think it will be a big difference.
Otherwise you can find the ICs on Ebay.

Rene_G7400

Quote from: Rene_G7400 on August 12, 2009, 05:38:56 PM
Quote from: VIDEOPAKBELGIUM on August 12, 2009, 05:14:48 PM
Is IC SN7400 the same as 74LS04 ? (as inverter for the rgb pcb)

No. You can use the SN7400 as an inverter, but the pinout is not the same.

It would be better to use 'LS' versions, except maybe for the 7407.