Throw hole alternative to ZX8-CCB?

[antoniovillena]

I am trying to replicate the Pokemon ZX8-CCB board with throw hole components. There is another board also based in Pokemon ZX8-CCB

http://www.oldcomp.cz/viewtopic.php?f=88&t=1809

But it has not color inversor. My idea is something like this:

backporch.png (7.24 KiB) Viewed 2955 times

But I don't know if this circuit would work. In case of yes, can I replace the diode by a 1N4148? Can I put fixed resistor instead of potentiometers?

Regards

[zz_indigo]

I did not know that somebody is reading my blog;-)

In your schematic is lot bugs.

1.) Bad regulator (must use 3.3V version)
2.) Bad RC circuit (Resistor to Power Capacitor to Ground)
3.) Diode is reversed.

If you can revers video in my circuit. Cut wire from pin 8 to pins 4 and 5 and create connection between pin 4(5) and 9(10)

But gates in package isn't equally sensitive. In worst case you must change trimer settings when switch video from/to inversed.

[antoniovillena]

I did not know that somebody is reading my blog;-)

In your schematic is lot bugs.

1.) Bad regulator (must use 3.3V version)

I copy this from your schematics.

2.) Bad RC circuit (Resistor to Power Capacitor to Ground)
3.) Diode is reversed.

Not a bug. I've inverted the signal, so I need interchange R and C and reverse diode.

If you can revers video in my circuit. Cut wire from pin 8 to pins 4 and 5 and create connection between pin 4(5) and 9(10)

But gates in package isn't equally sensitive. In worst case you must change trimer settings when switch video from/to inversed.

Ok. I'll try it later.

[zz_indigo]

I copy this from your schematics.

My fault. Must use 3.3V regulator. see mi next post (in slovak)

2.) Bad RC circuit (Resistor to Power Capacitor to Ground)
3.) Diode is reversed.

Not a bug. I've inverted the signal, so I need interchange R and C and reverse diode.

Most gates have internal pull-up resistor. A yet to be other reasons why it's not a good idea

[zz_indigo]

If you can revers video in my circuit. Cut wire from pin 8 to pins 4 and 5 and create connection between pin 4(5) and 9(10)

Mi fault!. bad gates.

When you reverse video you don't require generate backporch.

Cut wire from pin 11 to 1,2. And create connection betwen pin 12 to pins 1,2